Hot Rods Trouble shooting brakes

Danny do you have a adjustable proportional valve in the line?

 

My 2 cents. Only have built 1 SR and still having trouble with brakes but whenever I see others with problems I send them to MPBrakes. They had a wonderful booklet/catalog with much useful info and I heard great things about the advice they gave over the phone. Pedal ratio cylinder bore , pushrod lenght, spring return and gap, orientation of wheel cylinders for proper bleeding. , pad materiel, rotor diameter versus car weight and on and on. Seems more like a dollar and 2 cents. Sorry. My problem is a leaky combination valve. Thats another thing. What was put in for the proportioning valve.

 

I have this weekend off if you think I can be a help to you.

 

Gas money and beer ?

 

Are you a school teacher ? HRP

 

I plan on crawling under the car tomorrow afternoon and checking several thing that have been suggested. HRP

 

I've done that more times than I can count....but Danny would be better off if the beer drinking doesnt start till AFTER the work is done.

 

What about the lunch or dinner at Ruth Chris Steak House?

Gary

 

Any progress Danny?

 

Harry,I haven't had too much time to work on the brakes,there are a few things I have tried but they have not helped,I have may pal Earl coming over tomorrow afternoon,his shop is closed on fridays and he has done hundreds of brake jobs and offer to give me a helping hand.

I have convinced myself the master cylinder is the culprit but I have a lot of faith in Earl and he assures me he can tell me fairly quick if the master cylinder is the problem and he says he has the gauges to test . HRP

 

My friend Earl just left and we have come to the conclusion the pedal ratio is completely wrong and we need to get it on his lift to make access easier.

I am going to take it to his garage Tuesday. HRP

 

Not enough travel I take it?

 

Austin Speed Shop built the mechanics? Probably a mixup between owner/service mgr.
With all the power assists installed in 'Street rods' these days, the pedal may have been intentional for a 4-to-1 Power setup. Then changed at last minute...

 

Correct.

From what i understand they built the frame but the owner did all the brake work. HRP

 

Got a pic of the floor/pedal arrangement ?

 

Not any photos of the frame. HRP

 

Even the top side. You'll be looking for space and probably a new hole.

 

Best I have to offer . HRP

 

Bummer, It will be interesting to see what he put under there for a pedal assembly and if you can fix the ratio or will have to go to a different assembly.

 

Well I've seen it at least half a hundred times.




Two different pedals power 4:1 vs manual 6:1. Dimension "B" is usually the same about 2" and dimension "A" is what changes , 12":2" for manual and 8":2" for power. Sometimes the monkey with "B" a bit too.
The foot pedal needs to travel 6" or 4" also means the pedal is that far above the floor.

Some times that just won't fit and since it needs to fit and stop, well Sometimes you need to cheat the ratio. What's worked for me absolutely perfectly before is a small bore master and a itty bitty booster with down sized front caliper Pistons. The '95 geo metro master with 13/16 bore and booster are the smallest I know of & Speedway has GM style calipers in 3 different sizes, smaller stock and larger. Doing this I've got a 3:1 ratio to work flawlessly and the pressures were great. I've had to move the booster back and use a brake rod just because there's no room.

Now 32 fords have been done a million times without the issues you're having, wonder what's different?

Looking at your pedals now, how could you move the foot pad & hole to the firewall ?
Then dodge the steering column with your foot headed from gas to brake?

 

Hey Danny, I sent you the old mirrors and the new prop valve. I meant to send you the tracking info but I got distracted and forgot. Post Office said they would be there Saturday (tomorrow).

After doing a little investigating I found out my buddy who recommended the prop valve that's on the car now runs drum brakes on both ends of his car. So that might be the issue.

This new Wilwood valve is disc/drum and has a built in adjustable prop valve.

Hopefully that's it.

The next car I build I'm gonna run the under dash master with the hanging brake pedal. I'm done with floor mount masters.

 

So I heard you say you got the problem fixed,
What did you do to correct it?

 

Not 100% happy but I modified the brake pedal pretty much like the drawing you posted.

I have brakes but like I said I will keep playing with it until I am satisfied. HRP

 

I am having the same trouble with my brakes on my 27t, I found the raybestos mc39027 master cylinder on rock auto,but it doesn't seem to have the deep brake rod hole is there a specific, other than manual brake,number I should be looking for?

 

Yes and bleeding the system is a huge task

 

Danny, I only did a disc brake setup on one of my builds. It worked fine. I used 66 Volvo 122S front brakes / 67 rear Chevelle Drum rear brakes / Master cylinder 68 Chevelle Drum Type / Distribution block 68 Chevelle / Proportioning Valve Kelsey-Hayes # 74155
Not sure if any of this is relevant . If I remember correctly the drum brake master cylinder was necessary because the Volvo brakes had their own residual check valve and a disc brake master would cause lockup.
Good luck with it all. MB