[64speed]

I put my new hydraboost and clutch master cylinder on today with the Bowler Transmission clutch master adapter that bolts behind the brake booster to put the master cylinder in perfect geometry with the old pushrod. It comes with a bracket that you mount to the clutch pedal that allows you to connect the pushrood on the wilwood master because it does not thread out anywhere near long enough to reach the factory hole plus it would be in a bind if it did. I have two questions. First I got the bracket on the pedal and got the linkage hooked to it and all tightened down. The pedal has pretty decent travel but it feels like it bottoms out the master cylinder. Does anyone know if thats ok? Does anyone have any pictures of any pedal stops for an A body? I am guessing there is no way to insure this is correct until its plumbed and the throwout bearing is in the car. I am under the impression that the pedal stop is more to keep the throwout bearing from over extending that from the master bottoming out. Second, those of you with hydroboost. How much pedal travel do you have. I dont have much. I have about an inch to and inch and a half of travel and thats all the pedal goes. Seems like they are gonna be really touchy if thats the case. I mean if they work they work but do I need to be prepared for a trip thru the windshield before I get used to them haha?

[HWYSTR455]

Mine wasn't long enough either, I used a different clevis and rod to attach to the brake pedal. I too am using a Wilwood master, and I had to measure the booster pin depth, and modify the insert that goes in the master. Your pin protrusion from the hydraboost unit needs to be measured, and ensure there is the proper gap, just like you do with a typical booster. That is a critical clearance.

Master Power Brakes, and others, make a pin measurement tool, they are like $25.

Here's one: https://www.macsautoparts.com/ford_m...E&gclsrc=aw.ds

Usually, in a car/model that came with either manual/power brakes, there are 2 holes in the pedal body. For a hydraboost, I think you use the manual brake one, which is the upper hole. The objective is to ensure you have a straight shot for the rod to move towards the unit, no angle. If there's an angle, it will bind. There is also a factor of pedal ratio, but it doesn't matter with the hydraboost. With a vacuum booster, the lower hole provides a higher ratio, and that is why boosters are angled on a firewall.


Now for the HYD throwout, the throwout usually has an adjustable collar to adjust the at-rest clearance. Follow the instructions that come with the T.O. you have. With some HYD T.O.s, if there's too much clearance the cyl inside could eat up the seal faster. Leaking HYD T.O.s are a common thing by the way. But you just want to make sure the T.O. is properly adjusted.

In theory, once the T.O. travel reaches it's max travel, only thing that would really happen is that psi would increase. Same with max travel of the pressure plate.

After that's right, then you work on pedal throw and travel. I believe it's ok to have the pedal throw be longer than the travel of either the master, but it could wear out the master faster.

On the pedal/rod/master side, with manual brakes, the pin would just slam against the bore inside the master and stop. After a while of pounding on it, that bore could wear out faster. I think with a hydraboost, once the pin reaches max travel, the psi would just increase. That's not that bad of a condition, but it's a waste of leg and time. Sure there's a way to figure out what the travel of everything is, and you can limit the pedal travel to that amount.

With mechanical linkage, you take up all the slack, and then adjust for proper clearances, so it's very easy to do. If there's excessive pedal throw, you can limit the travel by replacing the OE rubber bumper with a bolt and 2 nuts, and adjust as needed. You can throw a rubber cap on the end of the bolt to deal with the click and/or rattle.

Hope that helps, sure someone else will chime in too.


.

[64speed]

I wish I could get a good picture of it. Bowler Transmission makes a bracket that bolts directly to the firewall to position the Wilwood master perfectly and then the make a bracket that bolts to the pedal that has the hole exactly where you need the hole to be when it is up flush with the brake pedal. I set it up today and then I mashed the clutch pedal and it felt like I bottomed out the master. I read about pedal stops but not sure how to fab one. As far as the hydraboost it’s a CPP matched set. I know some people call them Chinese junk but I have always had good luck with them. I will look and see what hole the pin is in.

[64speed]

Ok I moved the pedal pushrod for the hydroboost to the top hole. Full travel now.

[Tom Vaught]

Just saw this thread, Agree, that is where it goes.

Tom V.

[64speed]

Well I found a pedal stop that mounts to the pedal and is adjustable between 1 and 6 inches so that problem is solved.

[Lemans64]

Where did you find the pedal stop?? Is it a Universal thing or made for a 64?

[64speed]

This is awesome

[64speed]

The clutch master is still under warranty. I am kinda worried that I damaged it bottoming it out trying to get the geometry right. It’s not hooked to anything and has no pressure. The warranty will be out by the time it’s time to use. Should I swap it now?

[geeteeohguy]

Originally Posted by 64speed

The clutch master is still under warranty. I am kinda worried that I damaged it bottoming it out trying to get the geometry right. It’s not hooked to anything and has no pressure. The warranty will be out by the time it’s time to use. Should I swap it now?

Yes.

[Tom Vaught]

Hydra boost brakes take some time to get used to.
You CANNOT DO a Gorilla Stomp on them like a typical brake system.
They require a driver that has the ability to soft pedal the brake (as Bob Bonderant used to say).
Just because you used to push the pedal 4 inches on your old vehicle is no reason to think that
you should have the ability to do the same with a hydraboost system.

And another good part bites the dust due to .................................................

Tom V.

[64speed]

I talked to Wilwood today, they said no reason to exchange it as long as there was no fluid in it and it didn’t mash the plunger out the other side so no Tom a part was not destroyed. I did have to push it in several times to get it setup and I was not familiar with its travel nor am I clairvoyant. Better now than when everything is setup and blow up the throwout bearing

[Tom Vaught]

1) Manual Brake activation with the proper Master Cylinder size and brake lever ratio from the pedal to the master Cylinder take a given "force".

2) Power Brakes obviously have an "assist" capability from the vacuum of the engine and the pressure of the atmosphere to enable a softer pedal for the same braking ability.

3) Obviously Hydroboost applications allow engines with boosted engines to have the same brake capabilities as NA engines with Power Brakes.

In all cases there are relationships between the parts as far as how effective they work for a given pedal force.

Learning about brakes by experimentation is a good way to get yourself and your family members hurt. You should really farm the job out to a Hydroboost brake expert's shop.

Ford first used the Hydroboost systems on the 1996 Mustangs (large scale production) and some truck applications. The systems do work very well if set up properly. The key word being set up properly.

Mark at Luhn Performance has done several of the Hrdroboost systems in the past for Pontiac people.
None of the stuff he does is shade tree or half assed.

Just saying.

Tom V.

[64speed]

The hydroboost is a matched kit.... I don’t know more that I could do. I have the master cylinder in the top hole and now the pedal feels right of course it has no resistance though. As far as the clutch master I bought that pedal stop and will use it to sneak up on perfect clutch engage/disengagement. I’m not an engineer, I am doing the best I can and I personally think it’s turning out pretty good. Also I matched the master by recommendation. It is 1 1/8 bore. My best friend holds about 27 ASE certs. When I plumb the hydroboost he is gonna be here

[chuckies76ta]

I have the hydro-boost in my car. The pedal doesn't have alot of travel to activate the brakes. As mentioned, it doesn't take much force to brake. It will definitely lockup the front wheels. Takes a bit of getting use too, but they work great. I put a cooler on my system as I found the power steering fluid getting very hot.

Your not gonna damage the master cylinder by bottoming it out. As long as you haven't forced the crap out of it. It will only travel so far and then stop. It''s better once installed to leave a bit of travel at the end of engagement on the clutch master cylinder. You can accomplish that with the use of that clutch pedal stop unit you bought. I made my own travel stop and custom plate. The one thing these clutch master cylinders don't like is side forces or side loading while engaging the clutch. You need the clutch rod as straight as possible. Also, they talk about too much travel on the hydraulic bearing which will blow the seal out. So make sure you install and adjust the bearing properly.

Charles

[Tom Vaught]

Originally Posted by 64speed

It is 1 1/8 bore. My best friend holds about 27 ASE certs. When I plumb the hydroboost he is gonna be here

.

Not sure where you wound up with brake calipers on the front and rear of your vehicle.
Those parts will determine what size diameter Master cylinder diameter you need.

Example: With two large bore single piston calipers on a non power brake application, you almost need the SMALLEST Master Cylinder Piston Diameter to have sufficient pedal force to the calipers. You would like to be close to 1000 psi force to the calipers. In some cases, the measured pressure is around 600 psi on a gorilla stomp and you can barely stop the vehicle.

The smaller piston in the master cylinder helps that a little bit but when you have 6 piston calipers on the front on each side they consume a lot of fluid to move a few thousands of an inch "CPM" Caliper Piston Movement.

With a hydroboost system you can put a much larger master cylinder piston in the system and still have enough force to make the brakes work properly without excessive brake pedal force.
You trade brake pedal movement for brake caliper force against the brake rotors.

There are many "interactions"
You don't just bolt on some brake parts and expect the stuff to work properly unless you buy a ENGINEERED BRAKE SYSTEM, not individual components from 4 different places.
It also helps to have some concept of how the parts actually work together.

You are not a Brake System Engineer, I am not, and neither is your friend with 27 ASE certs. Buy a system from a known Hydroboost company for a similar vehicle like a 1966 Chevelle and use the parts they have matched up for that system vs thinking you know what you are doing or walking like a blind man across a busy New York street during rush hour.

The typical result is someone dies. Maybe not you (in your vehicle) but maybe someone in the vehicle that you rear-ended.

Tom V.