Master cylinder?

[svr]

Ok here's the set up, 57 3100 pickup, 235 with T5 trans, C4 front and rear suspension with 12" stock 88 corvette disc brakes all around. Looking for a master cylinder with booster that will go under the floor in the stock location. Brackets and mounting I can handle ok. What size bore on the master cylinder will work best? Am looking at a 1" bore master with a dual chamber 8" booster or do I need a 7" booster for more room? I know I will have to have a disc disc proportioning valve and residual valves for both the front and rear with this set up. Have considered a hydra boost set up but am not very familiar with how they work. All thoughts and suggestion welcome. Thanks

[Daze57]

check out Ogre,s thread he has done the hydro boost set up .
i am thinkin about goin that route also .

[mongocanfly]

Hydroboost brakes are great..especially for low vacuum engines. It simply uses hydraulic pressure from your power steering pump ..it takes up very little space..

[mongocanfly]

And it seems like we got more than one ogre depending on how you spell it..here's the build you want though..http://67-72chevytrucks.com/vboard/s...d.php?t=501998

[Coupeguy2001]

I put hydroboost on my 57.
works great

pressure from the pump goes to the hydroboost first. then there are two returns for the hydroboost. One goes to the pressure side of the power steering, and the other return has a rubber hose back to the inlet of the pump.
The rubber hose from the hydroboost and the rubber hose from the steering are teed together and go to pump inlet.
I made a bracket to mount hydroboost under floor, made a square adapter plate to rotate hydroboost 90 degrees, and used a remote reservoir so reservoir didn't hit the floor of the cab.
I pulled master and hydroboost from a 96 chevy dually.
two things,
hydroboost rubber hose fittings come in different sizes so if you have too much brake, use a larger fitting, and more fluid will go to the pump quicker. also, that fitting can affect your steering effort. if pressure is higher, steering will be easier.
I made all my lines and ran them in the frame, out of sight and harm's way.
Also, I cut the reservoir off the original master cylinder, and used what was left as a pedal bracket.

[dsraven]

hydroboost may be the best alternative for space and operation. they are easy enough to hook up. a second return line to the ps pump would be nice. they work whether you have vac wipers, low vac engine or whatever. like said, check ogres build and also check the hydrovac page on google for connections ,operation etc

[svr]

Thanks guy's, looks like hydroboost is the way I want to go, just bought a mustang hydroboost alla Ogre, small and compact it seems, may have to put a second return in the pump reservoir or try to T it first and see if it works. Will try the mustang proprietary valve first, if the balance isn't right might have to convert to an adjustable one. Question is with the unit frame mounted in the stock location will it need residual valves, might have to wait and see, master will be close to level with the calipers. Anybody else feel free to chime in.

[dsraven]

here are a couple of examples, looks like the same pic except one was from gm the other is off the net-pirate 4x4 site.
seems like it would take less space. you would need a p/s pump though. maybe another groove on the pulley to run the p/s pump.

[solidaxel]

Originally Posted by Coupeguy2001

I put hydroboost on my 57.
works great

pressure from the pump goes to the hydroboost first. then there are two returns for the hydroboost. One goes to the pressure side of the power steering, and the other return has a rubber hose back to the inlet of the pump.
The rubber hose from the hydroboost and the rubber hose from the steering are teed together and go to pump inlet.
I made a bracket to mount hydroboost under floor, made a square adapter plate to rotate hydroboost 90 degrees, and used a remote reservoir so reservoir didn't hit the floor of the cab.
I pulled master and hydroboost from a 96 chevy dually.
two things,
hydroboost rubber hose fittings come in different sizes so if you have too much brake, use a larger fitting, and more fluid will go to the pump quicker. also, that fitting can affect your steering effort. if pressure is higher, steering will be easier.
I made all my lines and ran them in the frame, out of sight and harm's way.
Also, I cut the reservoir off the original master cylinder, and used what was left as a pedal bracket.

What did you use to get the nut off of the hydro unit, or did you re fab the mounting plate?
For larger fittings are you talking about the 18 & 16mm fittings on the Hydrovac?

[dsraven]

here is a quick how to for the backyard guy who doesn't want to invest big bucks in a socket for the hydroboost nut

http://www.madwash.com/removenut_brakebooster.html

[solidaxel]

Looks good, Thanks
I will try them both!
I think I will try the second one, and clamp the angel in a vise

[Coupeguy2001]

I used a pipe wrench to break it loose. The threads are left hand I believe, so if you loosen it normally, you are tightening it.
I used metric to us standard adapters,from Ebay that are aircraft fittings compatible and used 3/8 and 7/16 tubing with AN fittings and made my lines.
I just made a Tee fitting work at the pump inlet using larger Tee and necked it down to where it goes in the pump.
I had a hose shop make the flex line from the line I made to the pump out pressure line.
So far, the only problem I have is the master cylinder has a check valve built into it for the rear brakes, and I had to gut the 10 PSI pressure residual valve so I did not trap fluid going to the rear brakes. I did not want to make another line to eliminate the residual valve, so I took out the internals.
Also, the accumulator went dead, and I had to buy a junk hydroboost with a good accumulator to install on mine. I also bought the tool to change it. Don't try to fix an accumulator.They are under about 350 PSI pressure, so don't mess with them.
Just work the master till it's relieved the reserve pressure, and the accumulator should just come off easy with the snap ring.
Try googling
my 57 revitalized

That's how I found my thread easiest the last time.
Some of the pics have gone away through time, but most of them are there.

[whitedog76]

I just recently pulled a hydroboost setup off of 03 Chevy van. (Last Saturday to be precise.)

It is about as simple of a setup as it gets.

I originally had planned on using a Jeep pedal assembly, but the pedal and bracket from the van came out super easy. Only one bolt held it on after the Hydroboost was removed. The bracket is very stout, looks like it will retrofit to the truck with ease. 4 bolt holes, center hole for the booster, that's all she wrote.

[Russell Ashley]

Chevy and GMC Astro vans had hyro boost so could also be a junk yard source. I definitely would go that route if I were at that point in my truck build, but passed that point a few years back.

[whitedog76]

The Astro van Hydroboost is at a crazy angle, so the mounting bracket will need to be modified. The 1500 series van is perpendicular, so it's easier to work with if mounting to the firewall or even modifying for under the floor.

It may be possible to use the Astro Master Cyl. on the van unit since it has a slightly smaller bore (1 1/4 vs. 1 3/8).

Just my $.02

[_Ogre]

Originally Posted by svr

Thanks guy's, looks like hydroboost is the way I want to go, just bought a mustang hydroboost alla Ogre, small and compact it seems, may have to put a second return in the pump reservoir or try to T it first and see if it works. Will try the mustang proprietary valve first, if the balance isn't right might have to convert to an adjustable one. Question is with the unit frame mounted in the stock location will it need residual valves, might have to wait and see, master will be close to level with the calipers. Anybody else feel free to chime in.

truk uses the mustang prop valve, it seems to work fine
as for residual valves: the location is borderline so i plumbed them in (easy with a bare frame)
i used the gm pump with the speedway flow reducer and everything works ok together
if i had to do it again i would use a ford pump since it has the correct flow and pressure

truk uses the stock pedal and swing arm, while i made the mount from scratch an easier plan has surfaced
cut both ends off the stock mc and run a heim joint thru the old mc to the new mc, this keeps the stock brake pivot
this also makes the hydroboost bracket a lot easier to fabricate



if you bought the mustang hydroboost and want a remote reservoir use the fittings and tank off a nissan quest/mercury villager



reservoir mounted on firewall

[svr]

Thanks Ogre, I am useing C4 R&P with the camero power steering pump, will see if they match ok or not without the restrictor. One question did you T the return line or use a double return pump? My mustang master should be here in the next day or 2.

[Coupeguy2001]

I have a friend that made the brass inserts for the holes where the plastic reservoir is supposed to mount.
That way, I don't need to get to it under the floor.
I used AN fittings, and ran aluminum tubing up to the firewall.
I mounted the remote reservoir where the original voltage regulator used to be.
I later made the plate between the masterr and the booster 1/4 inch since that one distorted so much.

Master is from a 1996 chevy Dually with a big block. 1 1/4" bore

[_Ogre]

i T'd the return line worked fine for the last 30,000 miles
with the c4 r&p you should be fine, never had a problem with the hydro just the steering
did you order a must hydro & mc or just the mc?
i picked my hydro up at a jy, when i needed a new mc oriellys had one in stock

[solidaxel]

I located a Mustang Hydro boost and the dia. of the bore in the M C is a 1 1/8" the 1 1/4" from the truck "may" be a little large for your vehicle, just say'n

[Coupeguy2001]

Seems to work ok, been in the truck for 6 years, and the the pedal effort is almost nothing.

[svr]

I have complete hydro and master, arrived today. From the research i've done the C4 master was 15/16 and the mustang is supposed to be 1". Not sure what the leaverage ratio was on the corvette or the mustang pedals but its going to be what ever the stock pedal was, sounds like it works. Going to make a square socket to take the nut off the hydro end so I can make a new mount that will keep it straight, mine has a slanted mounting plate. I like the brass inserts you have coupe, I have a lathe you have me thinking now, maybe 1/2" x 1/8" brass pipe bushings cut down to fit for materialq, gotta get the calipers out. Coupe what did you use for a reservoir?

[solidaxel]

Originally Posted by Coupeguy2001

Seems to work ok, been in the truck for 6 years, and the the pedal effort is almost nothing.

Sounds like you have a "proven" brake system

[Coupeguy2001]

I know that there has to be several part numbers for the hydroboosts.
Since I got my pieces out of a truck that was functioning with front disc, rear drum, my thinking was that even though the rear wheel cylinder might be smaller than the dually, the front calipers will be smaller too.
I could have gone with a smaller bore master for more braking force, GM must have thought they balanced their brake system based on empty weight and loaded weight.
The thing i do not have is the bias valve that is tied to the rear axle to the truck frame.
That valve increases the rear wheel pressure to the brakes.
For instance, when the truck is empty, the distance to the axle from the frame might be 8 inches. at that height, the bias valve closes the fluid pacth to the rear brakes by half.
When loaded, the truck sits 4 inches away from the axle, and the bias valve is fully open, allowing full braking pressure from the master as boosted to go to the rear cylinders.

At first, I was going to put that in, but since I hardly carry anything in the back that weights over 100 lbs, I left if out, and tried the existing setup.

The only thing I notice is that in the mornings, within the first mile of driving, the rear brakes are locking up on panic stops.
When it warms up, the rears are ok.
I have a proportioning valve in the rear brake line, and I kept turning it down little by little so now, it isn't noticeable at all.

[svr]

Lets see if these pics work, hydro and master are mounted, how do i tell which is the front port and which is the rear on both the master and the prop valve?