hydroboost
Oct 11, 2011 17:43:26 GMT -5
Post by sigmfsk on Oct 11, 2011 17:43:26 GMT -5
AZ Blues and I had some detailed discussion over on BBC about "hydroboost" starting around here. Here's a summary and pics and info of what I ended up receiving.
-------------------
I plan on using the stock front rotors, with 2002 Viper calipers, but I hadn't really worked out what to do for a power booster / master cylinder. Being that it all needed to be replaced, there seemed no sense in burdening the car with an old cast iron master cylinder. But it's not obvious what to replace the master cylinder with. The master cylinder is a 4-bolt (pic 1).
I could install a newer 2-bolt master cylinder with the adapter in pic 2 from
www.arengineering.com/mastercyl/mastercar/mastercar.html
But rather than go through all that trouble, why not just replace the booster & master cylinder together with a newer setup.
The guy that makes the 2-bolt adapter is
> ...partial to the [master cylinder] unit used in the 5th Avenue cars
www.4secondsflat.com/AR%20Engineering.htm
so why not use a master cylinder / power booster combo from a 1985 5th avenue (pic 3)?
Maybe no good reason. It might just bolt right up.
But I'm also thinking of a hydroboost - where you replace your vacuum powered booster with a hydraulically powered booster (from the power steering pump).
If you have (vacuum) power brakes and the engine dies, you get a few pumps before all the residual pressure is gone. Similarly, with (power steering) power brakes and the engine dies, you also get a few pumps. So there seems to be no difference there. And I wouldn't have to worry about vacuum (engine producing enough).
I talked with these guys:
www.hydratechbraking.com/Mopar_E_Body.html
about hooking me up with something for a 1974 Dodge Monaco.
When attempting to get parts for this car, the attitude of prospective sellers seems to fall into one of the following camps:
1) derision
2) begrudging assistance
3) regular good assistance
4) awesome assistance - neat project!
Larry the 8-track expert was a #4; I don't think anyone could ever match his enthusiasm.
Hydratech was a solid #3. My plan is to get the power booster with rod, take it to local auto parts store and see how a 1985 5th avenue setup compares, and then send the booster to Hydratech and see what they can come up with.
------------------
AZ Blues wrote:
I have been involved with installing Hydroboost systems in three street rods, and they are tricky. They can be a nightmare to bleed, and they are really grabby and unpredictable when they are not bled correctly; for example at higher RPMs, the pedal can stick to the floor with the slightest bit of air in the system or if the return line to the pump is slightly kinked. They also tend to weep a bit at the input shaft seal, and there is no replacing that without an entire new shaft assembly, because it's all swedged together and opening one up requires that you cut it off. And the accumulator is under very high pressure and is dangerous to mess with. Rebuilds are expensive and hit-or-miss, and if you go all aftermarket, you'll have $500 or more into it. Some vehicles like diesel pickups need them, because diesels don't make vacuum, but if you don't need it - best to just pass on it.
--------------------
I thanked him, then responded:
I spoke with the motor guys and I learned that my motor won't make enough vacuum to run a power booster. So it seems that my options are:
1) manual brakes
2) vacuum pump to run power booster
3) replace power booster with hydroboost
And I'm thinking that I'll always hate driving if I pick 1. And if I have to add on some ridiculous contraption, I'll be happier with #3 over #2, presuming it works.
The Swartz Performance link
www.schwartzperformance.com/
from the testimonial page at hydratech on the hydratech site:
hydratechbraking.com/testimonials_old/
shows a Dart Swinger and Cadillac. The Dart is clearly a "hydratech" brand model (pic 1).
The Cadillac (pic 2) is a hydroboost of some sort - doesn't look like a "hydratech" brand.
pic 3 is of a 69 Camaro with a hydratech
It's only 937 HP, but I guess that's enough to go pickup the groceries.
pic 4 is another nice Camaro with a hydratech
> [from AZB] if you don't need it - best to just pass on it.
Well, I'm thinking I might need it.
But, I'm wondering if your experience has been specifically with "hydratech", or just hydroboost setups in general (reusing factory setups from boneyards, or other brands). I'll proceed with caution, but it looks like some folks are having some success (I hope).
-------------------
AZ Blues responded:
Two of the systems I have done were rebuilt parts store boosters with custom mounts and lines, one was an aftermarket kit for a Chevy truck from one of the 4 wheeler dealers. It was a nice kit that worked well.
The Hydro-Boost unit is a Bosch design (and brand name) that dates back to the early '70s. The oldest vehicle that I saw one on was a '73 LTD Squire wagon, and they were used an all kinds of Lincolns, big GM cars, and trucks to 2 ton from the '70s-on. Most recently they were used in Mustang Cobras because a regular booster wouldn't fit the engine bay with that big honkin' 4 cam modular motor. They are popular in street rods for the same reason - compact design with no vacuum can - but usually longer than a vacuum booster - so make sure you have the room. Shouldn't be a problem in a C-barge.
All of the boosters are made by Bosch, and all are rebuilt stock units from one application or another, and several companies sell kits to put them in vehicles that they didn't come in. HydraTech and the others make custom machined aluminum mounts, push rod assemblies, hydraulic lines, and sometimes pedals to adapt these units, but they rely on rebuilders for the units themselves. There are two basic types of units: inline accumulator (the little reserve pressure can) and the more common side mounted accumulator. The systems operate at up to 2,500 PSI BTW, so make sure the high pressure lines are in very good shape and away from anything that can abrade them.
The booster takes a little bit of getting used to, because it is very powerful and does not have the mushy feeling associated with most vacuum boosters. They are a true one-toe system no matter what they are installed in. It's very important to use an appropriate master cylinder, because one with a piston that is too small will have too much pressure, and with the fast-acting nature of the booster, will try to toss you through the windshield if you hit the brakes too hard. Believe me on that one. In most systems, a piston size of about 1-1/8" works well. Many systems also need an adjustable proportioning valve to the rear line to cut the pressure on rear drum brakes, so they don't prematurely lock up. Not a problem if you convert to rear disc, a recommended upgrade to a heavy car.
One important tip, which you are doing but that anyone considering Hydro-Boost should heed, is that if you convert to this system, EVERYTHING associated with the P/S system, including the steering box, has to be replaced with competently rebuilt parts - and all lines MUST be new. Everywhere. P/S lines can look OK on the outside, but they wear internally and break down inside first, shedding little flakes of rubber which wreak havoc with the many screens and fine passages inside the Hydro-Boost unit, so you start off all new.
Ordinarily, I'd just suggest you go with a less radical cam so you can make vacuum to run a regular booster, but you seem to have your heart set on a fairly radical 550+ HP RB motor - which is appropriate in a big heavy car like these, because it will end up feeling about like a Mustang or Camaro with 400 HP - which isn't a bad thing.
Below is a Hydro-Boost setup that I did in a '37 Ford pickup.
Lowered street rod with under floor booster meant no room for a vacuum unit - it would have scraped the ground on a tall speed bump. The original application for this unit was late model Ford diesel Super Duty pickup. All custom lines, No kit used.
-------------------
me again:
> All of the boosters are made by Bosch, and all are rebuilt stock units from
> one application or another, and several companies sell kits to put them in vehicles
> that they didn't come in. HydraTech and the others make custom machined
> aluminum mounts, push rod assemblies, hydraulic lines, and sometimes pedals to a
> dapt these units, but they rely on rebuilders for the units themselves.
Ahhh, good to know. Both that:
1) everyone is using the same Bosch unit
2) HydraTech might be well situated to help with a "custom" 1974 Monaco setup.
> The systems operate at up to 2,500 PSI BTW, so make sure the high pressure lines
> are in very good shape and away from anything that can abrade them.
I see that the HydraTech kits come with hoses with the ends for the hydroboost alrady crimped on, and the user cuts the lines to length and crimps the ends for the power steering gear and pump:
Hydratech Braking Systems :: Hose, Fittings and Adapter Listings
www.hydratechbraking.com/hose_fittings.html
There's a video here about installing the fittings, although it didn't make clear that part of the work was already done
www.V8TVshow.com - Hydroboost Brake Booster Cures Bad Brakes
v8tvshow.com/content/view/125/73/
Looks similar to standard AN fitting installation.
> The booster takes a little bit of getting used to, because it is very powerful and
> does not have the mushy feeling associated with most vacuum boosters. They are
> a true one-toe system no matter what they are installed in.
That seems to be a universal description:
> ...you need to watch and make sure that you don't kiss the steering wheel, and
> that he has to peel his eyeballs off the windshield.
Corvette Forum - View Single Post - Brake Upgrade Help !!!
forums.corvetteforum.com/1544228048-post10.html
> It's very important to use an appropriate master cylinder, because one with a
> piston that is too small will have too much pressure, and with the fast-acting nature
> of the booster, will try to toss you through the windshield if you hit the brakes too
> hard. Believe me on that one. In most systems, a piston size of about 1-1/8" works
> well.
I see this thread:
C6 Z06 brakes, Hydratech Booster, and Master Cyl. ?'s
www.pro-touring.com/showthread.php?29173-C6-Z06-brakes-Hydratech-Booster-and-Master-Cyl.-s
talking about hydratech recommending 1 1/8" and a guy going to try a 1" anyway. No updates on how that worked out.
I'll keep you posted on what they recommend for my setup.
> Many systems also need an adjustable proportioning valve to the rear line to cut
> the pressure on rear drum brakes, so they don't prematurely lock up. Not a problem
> if you convert to rear disc, a recommended upgrade to a heavy car.
Upgrading to rear discs wasn't a priority for me, but with swapping out the c-clip axles for bolt-in axles, it kind of made the swap to discs an easy upgrade. So I'll have a disc/disc setup, with a disc/disc master cylinder, and proportioning valve.
> One important tip, which you are doing but that anyone considering Hydro-Boost
> should heed, is that if you convert to this system, EVERYTHING associated with the
> P/S system, including the steering box, has to be replaced with competently
> rebuilt parts - and all lines MUST be new. Everywhere. P/S lines can look OK on
> the outside, but they wear internally and break down inside first, shedding little flakes
> of rubber which wreak havoc with the many screens and fine passages inside
> the Hydro-Boost unit, so you start off all new.
A good point. All that will be new. After the bead blasting, it's almost cheaper to install new stuff than re-install the old stuff.
> Ordinarily, I'd just suggest you go with a less radical cam so you can make vacuum
> to run a regular booster, but you seem to have your heart set on a fairly radical
> 550+ HP RB motor.
And how!
> Below is a Hydro-Boost setup that I did in a '37 Ford pickup...All custom lines, No
> kit used.
Thanks AZB for your detailed info and pic. They will help me in my discussions with Hydratech and my decision to get one or not.
-------------------------
I then moved forward with the hydratech plan:
Jim from hydratech received my power booster, pic 1
He said they could hook me up, and their best match would be a custom job that was similar to their Chrysler e-body kit:
Hydratech Braking Systems :: '70-'74 Chrysler E Body Hydraulic Brake Assist System Listings
www.hydratechbraking.com/Mopar_E_Body.html
Notice that their kit
> Eliminates the factory stamped steel firewall re-inforcement plate
On the phone, he referred to it as a "filler plate". You can see it in the picture of my booster.
pic 2:
is a good reference pic from
B Body Mopar Forums - View Single Post - Power booster mounting problems!
www.forbbodiesonly.com/moparforum/showpost.php?p=91158&postcount=7
> The backing plate is for firewall reinforcement, otherwise the firewall will flex
> under braking.
On the phone, Jim asked if I had a particular desire to keep the filler plate, and I said no, and he said that was standard (for their kit to replace the power booster and filler plate).
But looking at pictures, it seems that their billet mounting plate does not have the same surface area mounting as the original filler plate (pic 3).
I wonder if its that way just for looks (no mounting plate looks "cooler" than a huge mounting plate)? I suppose that if this unit requires less power on the pedal to operate the brakes, then someone may not be pushing the pedal hard enough to bend the firewall, so the backing plate may not be needed. But if Ma Mopar decided that a backing plate was needed to keep the firewall from flexing under extreme foot stomping, I'd rather like to keep it (or have the new billet mounting plate have the same mounting locations).
He recommended the new 2-bolt Chrysler master cylinder, 1 1/8" bore, used from 83-93. They have it with either a black or white reservoir (pic 4).
He said that a 1 1/8" bore MC was a setup that has worked well for them. 1" was way too small. I asked about 1 1/4" and he said it was doable, but 1 1/8" was more common and they had good feedback on it. He gave the following examples of how much the brake pedal would typically move with a 1 1/8" bore:
0.5" : backing out of driveway then stopping
1.0" : stopping normally
2.0" : "climbing all over" the brakes
I'm thinking of using their kit, but KEEPING the backing plate. I think it will look fine clean and painted. Please let me know if you have any thoughts on it.
---------------------
and I continued:
So I'm talking with Jim of Hydratech, explaining to him that I would like to keep the vacuum booster backing plate, as I don't want to lose any firewall rigidity. He was thinking of doing away with the backing plate and I got to his line of reasoning:
1) the only surface area of the backing plate that actually bolted to the firewall was the part covered by the white gasket in pic 1.
2) being that no other part bolted to the firewall, the backing plate could be done away with, because the billet aluminum block between the firewall and the hydroboost would be much stiffer than the backing plate.
Remember that the Mopars that they sell kits for are:
> 1964 - 1974 MOPAR B BODY VEHICLES -
> GTX / ROADRUNNER / CHARGER / CORONET / FURY / SUPER BEE / BELVEDERE
> 1970 - 1974 MOPAR E BODY VEHICLES -
> BARRACUDA / CHALLENGER
> 1964 - 1974 MOPAR A BODY VEHICLES -
> DUSTER / DART / VALIANT / DEMON / EARLY BARRACUDA
And this line of thinking (that the backing plate doesn't bolt to the firewall anywhere else other than the white gasket area) appears correct for these cars. I provide pics 2,3,4 from e-bay showing 1971 b/e/a body cars.
But I sure am glad I take pictures. Pic 5 shows that on the Monaco, the backing plate DOES bolt to the firewall outside the white gasket.
It spreads the load from the fender across the firewall.
Just another cool aspect of working on a 1974 c-body. Now I can say, "of course the backing plate attaches to the firewall outside the white gasket area".
--------------------
and my last update:
I got my setup back from Hydratech. I'm pretty happy with it so far.
pic 1: with backing plate installed.
Recall that hydratech wanted to make the unit so that it would NOT reuse the backing plate. But I found that the Monaco (unlike their standard a/b/e body lineup) uses the backing plate to help support a firewall to fender bracket:
www.bluesbrotherscentral.com/forum/bluesmobiles/10217-theres-new-marin-county-sheriff-town-8.html#post123500
So they made this model such that it is designed to be used with the backing plate (adjusting the standard aluminum block thickness and pushrod length as necessary).
pic 2: showing back without backing plate
pic 3: front
pic 4: The only important dimension that looked different than stock was the width of the pushrod receptacle that mates to the clevis on the brake pedal was narrower than stock. Spacers can take care of that, although it wouldn't hurt to simply make a sturdier piece that was the correct size.
[regarding the dimensional note regarding pic 4, I asked hydratech about it, and Jim responded:
> ...the brake pedal rod adapter is specifically designed to be self aligning to the
> connection on the pedal, and we actually do not specify that any shims / washers be
> used (as they can induce linkage binding)...
Instead of
> we do not specify that shims be used
I thought they might mean
> we specify that shims not be used
but I can't find that anywhere in the documentation. Anyway, it looks like it's good to go as-is.
]
My paperwork doesn't show this as a 1974 Dodge Monaco kit. It is listed as a 70-74 Mopar E Body (71-74 B Body) Level III Hydraulic Brake Assist System with PS line set (Mopar spec MC pushrod) Hybrid Model.
Hybrid Model? What? It should be called the Bluesmobile model!
--------------------------
Thanks AZ Blues for your input and info!
--------------------------
From archived info starting here:
www.bluesbrotherscentral.com/forum/topic/8327-theres-a-new-marin-county-sheriff-in-town/page__view__findpost__p__118178
-------------------
I plan on using the stock front rotors, with 2002 Viper calipers, but I hadn't really worked out what to do for a power booster / master cylinder. Being that it all needed to be replaced, there seemed no sense in burdening the car with an old cast iron master cylinder. But it's not obvious what to replace the master cylinder with. The master cylinder is a 4-bolt (pic 1).
I could install a newer 2-bolt master cylinder with the adapter in pic 2 from
www.arengineering.com/mastercyl/mastercar/mastercar.html
But rather than go through all that trouble, why not just replace the booster & master cylinder together with a newer setup.
The guy that makes the 2-bolt adapter is
> ...partial to the [master cylinder] unit used in the 5th Avenue cars
www.4secondsflat.com/AR%20Engineering.htm
so why not use a master cylinder / power booster combo from a 1985 5th avenue (pic 3)?
Maybe no good reason. It might just bolt right up.
But I'm also thinking of a hydroboost - where you replace your vacuum powered booster with a hydraulically powered booster (from the power steering pump).
If you have (vacuum) power brakes and the engine dies, you get a few pumps before all the residual pressure is gone. Similarly, with (power steering) power brakes and the engine dies, you also get a few pumps. So there seems to be no difference there. And I wouldn't have to worry about vacuum (engine producing enough).
I talked with these guys:
www.hydratechbraking.com/Mopar_E_Body.html
about hooking me up with something for a 1974 Dodge Monaco.
When attempting to get parts for this car, the attitude of prospective sellers seems to fall into one of the following camps:
1) derision
2) begrudging assistance
3) regular good assistance
4) awesome assistance - neat project!
Larry the 8-track expert was a #4; I don't think anyone could ever match his enthusiasm.
Hydratech was a solid #3. My plan is to get the power booster with rod, take it to local auto parts store and see how a 1985 5th avenue setup compares, and then send the booster to Hydratech and see what they can come up with.
------------------
AZ Blues wrote:
I have been involved with installing Hydroboost systems in three street rods, and they are tricky. They can be a nightmare to bleed, and they are really grabby and unpredictable when they are not bled correctly; for example at higher RPMs, the pedal can stick to the floor with the slightest bit of air in the system or if the return line to the pump is slightly kinked. They also tend to weep a bit at the input shaft seal, and there is no replacing that without an entire new shaft assembly, because it's all swedged together and opening one up requires that you cut it off. And the accumulator is under very high pressure and is dangerous to mess with. Rebuilds are expensive and hit-or-miss, and if you go all aftermarket, you'll have $500 or more into it. Some vehicles like diesel pickups need them, because diesels don't make vacuum, but if you don't need it - best to just pass on it.
--------------------
I thanked him, then responded:
I spoke with the motor guys and I learned that my motor won't make enough vacuum to run a power booster. So it seems that my options are:
1) manual brakes
2) vacuum pump to run power booster
3) replace power booster with hydroboost
And I'm thinking that I'll always hate driving if I pick 1. And if I have to add on some ridiculous contraption, I'll be happier with #3 over #2, presuming it works.
The Swartz Performance link
www.schwartzperformance.com/
from the testimonial page at hydratech on the hydratech site:
hydratechbraking.com/testimonials_old/
shows a Dart Swinger and Cadillac. The Dart is clearly a "hydratech" brand model (pic 1).
The Cadillac (pic 2) is a hydroboost of some sort - doesn't look like a "hydratech" brand.
pic 3 is of a 69 Camaro with a hydratech
It's only 937 HP, but I guess that's enough to go pickup the groceries.
pic 4 is another nice Camaro with a hydratech
> [from AZB] if you don't need it - best to just pass on it.
Well, I'm thinking I might need it.
But, I'm wondering if your experience has been specifically with "hydratech", or just hydroboost setups in general (reusing factory setups from boneyards, or other brands). I'll proceed with caution, but it looks like some folks are having some success (I hope).
-------------------
AZ Blues responded:
Two of the systems I have done were rebuilt parts store boosters with custom mounts and lines, one was an aftermarket kit for a Chevy truck from one of the 4 wheeler dealers. It was a nice kit that worked well.
The Hydro-Boost unit is a Bosch design (and brand name) that dates back to the early '70s. The oldest vehicle that I saw one on was a '73 LTD Squire wagon, and they were used an all kinds of Lincolns, big GM cars, and trucks to 2 ton from the '70s-on. Most recently they were used in Mustang Cobras because a regular booster wouldn't fit the engine bay with that big honkin' 4 cam modular motor. They are popular in street rods for the same reason - compact design with no vacuum can - but usually longer than a vacuum booster - so make sure you have the room. Shouldn't be a problem in a C-barge.
All of the boosters are made by Bosch, and all are rebuilt stock units from one application or another, and several companies sell kits to put them in vehicles that they didn't come in. HydraTech and the others make custom machined aluminum mounts, push rod assemblies, hydraulic lines, and sometimes pedals to adapt these units, but they rely on rebuilders for the units themselves. There are two basic types of units: inline accumulator (the little reserve pressure can) and the more common side mounted accumulator. The systems operate at up to 2,500 PSI BTW, so make sure the high pressure lines are in very good shape and away from anything that can abrade them.
The booster takes a little bit of getting used to, because it is very powerful and does not have the mushy feeling associated with most vacuum boosters. They are a true one-toe system no matter what they are installed in. It's very important to use an appropriate master cylinder, because one with a piston that is too small will have too much pressure, and with the fast-acting nature of the booster, will try to toss you through the windshield if you hit the brakes too hard. Believe me on that one. In most systems, a piston size of about 1-1/8" works well. Many systems also need an adjustable proportioning valve to the rear line to cut the pressure on rear drum brakes, so they don't prematurely lock up. Not a problem if you convert to rear disc, a recommended upgrade to a heavy car.
One important tip, which you are doing but that anyone considering Hydro-Boost should heed, is that if you convert to this system, EVERYTHING associated with the P/S system, including the steering box, has to be replaced with competently rebuilt parts - and all lines MUST be new. Everywhere. P/S lines can look OK on the outside, but they wear internally and break down inside first, shedding little flakes of rubber which wreak havoc with the many screens and fine passages inside the Hydro-Boost unit, so you start off all new.
Ordinarily, I'd just suggest you go with a less radical cam so you can make vacuum to run a regular booster, but you seem to have your heart set on a fairly radical 550+ HP RB motor - which is appropriate in a big heavy car like these, because it will end up feeling about like a Mustang or Camaro with 400 HP - which isn't a bad thing.
Below is a Hydro-Boost setup that I did in a '37 Ford pickup.
Lowered street rod with under floor booster meant no room for a vacuum unit - it would have scraped the ground on a tall speed bump. The original application for this unit was late model Ford diesel Super Duty pickup. All custom lines, No kit used.
-------------------
me again:
> All of the boosters are made by Bosch, and all are rebuilt stock units from
> one application or another, and several companies sell kits to put them in vehicles
> that they didn't come in. HydraTech and the others make custom machined
> aluminum mounts, push rod assemblies, hydraulic lines, and sometimes pedals to a
> dapt these units, but they rely on rebuilders for the units themselves.
Ahhh, good to know. Both that:
1) everyone is using the same Bosch unit
2) HydraTech might be well situated to help with a "custom" 1974 Monaco setup.
> The systems operate at up to 2,500 PSI BTW, so make sure the high pressure lines
> are in very good shape and away from anything that can abrade them.
I see that the HydraTech kits come with hoses with the ends for the hydroboost alrady crimped on, and the user cuts the lines to length and crimps the ends for the power steering gear and pump:
Hydratech Braking Systems :: Hose, Fittings and Adapter Listings
www.hydratechbraking.com/hose_fittings.html
There's a video here about installing the fittings, although it didn't make clear that part of the work was already done
www.V8TVshow.com - Hydroboost Brake Booster Cures Bad Brakes
v8tvshow.com/content/view/125/73/
Looks similar to standard AN fitting installation.
> The booster takes a little bit of getting used to, because it is very powerful and
> does not have the mushy feeling associated with most vacuum boosters. They are
> a true one-toe system no matter what they are installed in.
That seems to be a universal description:
> ...you need to watch and make sure that you don't kiss the steering wheel, and
> that he has to peel his eyeballs off the windshield.
Corvette Forum - View Single Post - Brake Upgrade Help !!!
forums.corvetteforum.com/1544228048-post10.html
> It's very important to use an appropriate master cylinder, because one with a
> piston that is too small will have too much pressure, and with the fast-acting nature
> of the booster, will try to toss you through the windshield if you hit the brakes too
> hard. Believe me on that one. In most systems, a piston size of about 1-1/8" works
> well.
I see this thread:
C6 Z06 brakes, Hydratech Booster, and Master Cyl. ?'s
www.pro-touring.com/showthread.php?29173-C6-Z06-brakes-Hydratech-Booster-and-Master-Cyl.-s
talking about hydratech recommending 1 1/8" and a guy going to try a 1" anyway. No updates on how that worked out.
I'll keep you posted on what they recommend for my setup.
> Many systems also need an adjustable proportioning valve to the rear line to cut
> the pressure on rear drum brakes, so they don't prematurely lock up. Not a problem
> if you convert to rear disc, a recommended upgrade to a heavy car.
Upgrading to rear discs wasn't a priority for me, but with swapping out the c-clip axles for bolt-in axles, it kind of made the swap to discs an easy upgrade. So I'll have a disc/disc setup, with a disc/disc master cylinder, and proportioning valve.
> One important tip, which you are doing but that anyone considering Hydro-Boost
> should heed, is that if you convert to this system, EVERYTHING associated with the
> P/S system, including the steering box, has to be replaced with competently
> rebuilt parts - and all lines MUST be new. Everywhere. P/S lines can look OK on
> the outside, but they wear internally and break down inside first, shedding little flakes
> of rubber which wreak havoc with the many screens and fine passages inside
> the Hydro-Boost unit, so you start off all new.
A good point. All that will be new. After the bead blasting, it's almost cheaper to install new stuff than re-install the old stuff.
> Ordinarily, I'd just suggest you go with a less radical cam so you can make vacuum
> to run a regular booster, but you seem to have your heart set on a fairly radical
> 550+ HP RB motor.
And how!
> Below is a Hydro-Boost setup that I did in a '37 Ford pickup...All custom lines, No
> kit used.
Thanks AZB for your detailed info and pic. They will help me in my discussions with Hydratech and my decision to get one or not.
-------------------------
I then moved forward with the hydratech plan:
Jim from hydratech received my power booster, pic 1
He said they could hook me up, and their best match would be a custom job that was similar to their Chrysler e-body kit:
Hydratech Braking Systems :: '70-'74 Chrysler E Body Hydraulic Brake Assist System Listings
www.hydratechbraking.com/Mopar_E_Body.html
Notice that their kit
> Eliminates the factory stamped steel firewall re-inforcement plate
On the phone, he referred to it as a "filler plate". You can see it in the picture of my booster.
pic 2:
is a good reference pic from
B Body Mopar Forums - View Single Post - Power booster mounting problems!
www.forbbodiesonly.com/moparforum/showpost.php?p=91158&postcount=7
> The backing plate is for firewall reinforcement, otherwise the firewall will flex
> under braking.
On the phone, Jim asked if I had a particular desire to keep the filler plate, and I said no, and he said that was standard (for their kit to replace the power booster and filler plate).
But looking at pictures, it seems that their billet mounting plate does not have the same surface area mounting as the original filler plate (pic 3).
I wonder if its that way just for looks (no mounting plate looks "cooler" than a huge mounting plate)? I suppose that if this unit requires less power on the pedal to operate the brakes, then someone may not be pushing the pedal hard enough to bend the firewall, so the backing plate may not be needed. But if Ma Mopar decided that a backing plate was needed to keep the firewall from flexing under extreme foot stomping, I'd rather like to keep it (or have the new billet mounting plate have the same mounting locations).
He recommended the new 2-bolt Chrysler master cylinder, 1 1/8" bore, used from 83-93. They have it with either a black or white reservoir (pic 4).
He said that a 1 1/8" bore MC was a setup that has worked well for them. 1" was way too small. I asked about 1 1/4" and he said it was doable, but 1 1/8" was more common and they had good feedback on it. He gave the following examples of how much the brake pedal would typically move with a 1 1/8" bore:
0.5" : backing out of driveway then stopping
1.0" : stopping normally
2.0" : "climbing all over" the brakes
I'm thinking of using their kit, but KEEPING the backing plate. I think it will look fine clean and painted. Please let me know if you have any thoughts on it.
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and I continued:
So I'm talking with Jim of Hydratech, explaining to him that I would like to keep the vacuum booster backing plate, as I don't want to lose any firewall rigidity. He was thinking of doing away with the backing plate and I got to his line of reasoning:
1) the only surface area of the backing plate that actually bolted to the firewall was the part covered by the white gasket in pic 1.
2) being that no other part bolted to the firewall, the backing plate could be done away with, because the billet aluminum block between the firewall and the hydroboost would be much stiffer than the backing plate.
Remember that the Mopars that they sell kits for are:
> 1964 - 1974 MOPAR B BODY VEHICLES -
> GTX / ROADRUNNER / CHARGER / CORONET / FURY / SUPER BEE / BELVEDERE
> 1970 - 1974 MOPAR E BODY VEHICLES -
> BARRACUDA / CHALLENGER
> 1964 - 1974 MOPAR A BODY VEHICLES -
> DUSTER / DART / VALIANT / DEMON / EARLY BARRACUDA
And this line of thinking (that the backing plate doesn't bolt to the firewall anywhere else other than the white gasket area) appears correct for these cars. I provide pics 2,3,4 from e-bay showing 1971 b/e/a body cars.
But I sure am glad I take pictures. Pic 5 shows that on the Monaco, the backing plate DOES bolt to the firewall outside the white gasket.
It spreads the load from the fender across the firewall.
Just another cool aspect of working on a 1974 c-body. Now I can say, "of course the backing plate attaches to the firewall outside the white gasket area".
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and my last update:
I got my setup back from Hydratech. I'm pretty happy with it so far.
pic 1: with backing plate installed.
Recall that hydratech wanted to make the unit so that it would NOT reuse the backing plate. But I found that the Monaco (unlike their standard a/b/e body lineup) uses the backing plate to help support a firewall to fender bracket:
www.bluesbrotherscentral.com/forum/bluesmobiles/10217-theres-new-marin-county-sheriff-town-8.html#post123500
So they made this model such that it is designed to be used with the backing plate (adjusting the standard aluminum block thickness and pushrod length as necessary).
pic 2: showing back without backing plate
pic 3: front
pic 4: The only important dimension that looked different than stock was the width of the pushrod receptacle that mates to the clevis on the brake pedal was narrower than stock. Spacers can take care of that, although it wouldn't hurt to simply make a sturdier piece that was the correct size.
[regarding the dimensional note regarding pic 4, I asked hydratech about it, and Jim responded:
> ...the brake pedal rod adapter is specifically designed to be self aligning to the
> connection on the pedal, and we actually do not specify that any shims / washers be
> used (as they can induce linkage binding)...
Instead of
> we do not specify that shims be used
I thought they might mean
> we specify that shims not be used
but I can't find that anywhere in the documentation. Anyway, it looks like it's good to go as-is.
]
My paperwork doesn't show this as a 1974 Dodge Monaco kit. It is listed as a 70-74 Mopar E Body (71-74 B Body) Level III Hydraulic Brake Assist System with PS line set (Mopar spec MC pushrod) Hybrid Model.
Hybrid Model? What? It should be called the Bluesmobile model!
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Thanks AZ Blues for your input and info!
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From archived info starting here:
www.bluesbrotherscentral.com/forum/topic/8327-theres-a-new-marin-county-sheriff-in-town/page__view__findpost__p__118178