82-92 F body brake help

MYLINRACING · 07-14-2015, 09:59 PM

I have a 86 trans-am and it has a Ed Quay master cylinder and pedal setup. I have Aerospace disc on the front and drum brakes on the rear, also have a 10 pound residual valve on the rear drums. I can not get the car to hold above 2200 rpms without it creeping in the lights I want to get it to at least 3000 rpms. Any suggestion on what to try next?

thanks

HandOverFist · 07-15-2015, 01:09 AM

Four piston on the front? Add four pistons to the rear and it will hold just about anything you throw at it. Two-step helps a bit also.

rod butcher · 07-15-2015, 07:48 AM

Check brake pressure front and rear. It should be above 1000 - 1200 psi. The rear brakes hold the car. We used to use extra thick shoes and uncut drums in the old days to hold it on the line. Now a dual caliper set-up in the rear is the norm. Our small block car holds at 3400 on 2 step with 4 wheel disc.

Lee Valentine · 07-15-2015, 06:12 PM

Have an 87 came to Ply. Violate master cylinder stock brakes front and rear holds at 3200 no problem.Foot braking or 2 step.

Jim Whitehead · 07-15-2015, 08:46 PM

Rear brakes out of adjustment. I have 86 F-Body 305 stocker can hold at 3500 no problem. Front disc rear drum. Buy two sets of rear brake shoes use all four of the big shoes. Resurface drums for smooth and even contact.

Eman · 07-19-2015, 11:47 AM

Quote:

Originally Posted by MYLINRACING

I have a 86 trans-am and it has a Ed Quay master cylinder and pedal setup. I have Aerospace disc on the front and drum brakes on the rear, also have a 10 pound residual valve on the rear drums. I can not get the car to hold above 2200 rpms without it creeping in the lights I want to get it to at least 3000 rpms. Any suggestion on what to try next?

thanks

You either have an incredibly tight converter or a brake problem.
My 3rd gen has a Chrysler MC, 1.032 bore with a factory pedal modified to 6:1 pedal ratio by raising the rod attachment point. Factory disc on the frt. and Ford drums on the back and all stainless flex lines. I have held at 4k on the starting line with no problems. Drum brakes will hold a car better than disc as they are self energizing. That is why emergency brakes work better in fwd than reverse.
Use basic hydraulics to determine your problem. To increase rear brake application use the largest bore wheel cyls you can find for your brakes. I use 2 sets of shoes and only install the long secondary shoes in both positions, more surface area. No need for residual ck valves if the MC is on the firewall. Should be no need for a prop valve and if you do install one use an adjustable one in the frt. line to stop frt. brake lockup at the stripe.

Nick_Siebert · 07-20-2015, 10:14 AM

Do yourself a favor and buy yourself a set of Strange, MW, or Lamb front brakes instead. I went through the same problems in the same style car with Aerospace, they told me it was all kinds of things causing problems and I finally got fed up and ordered a new set of Strange brakes, fixed all of them immediately.

Signman · 07-20-2015, 06:06 PM

Wilwood MC 260-4893 1 1/16 in. bore

The 1 1/8 bore is recommended but makes the pedal really hard and you will have to put some leg in it. The smaller bore makes the pedal a little spongy and better feel at different RPM. Step down really hard and you will be late.
Run Aerospace on all four and can hold to 3500.

brian schuetta · 07-22-2015, 12:11 PM

Did you drill the hole for the Clevis to attach to the brake pedal lever higher than stock? These cars never had two holes drilled in the pedal lever like older ones that came with manual and power brakes. I drilled mine around an inch or so higher, copied a 69' Camaro dimension. I used four primary shoes and I think 7/8" or 1" brake cylinders from a 69' station wagon.

07-14-2015, 09:59 PM	#1
MYLINRACING Junior Member Join Date: Dec 2004 Location: CHARLESTON Posts: 63 Likes: 11 Liked 1 Time in 1 Post	82-92 F body brake help I have a 86 trans-am and it has a Ed Quay master cylinder and pedal setup. I have Aerospace disc on the front and drum brakes on the rear, also have a 10 pound residual valve on the rear drums. I can not get the car to hold above 2200 rpms without it creeping in the lights I want to get it to at least 3000 rpms. Any suggestion on what to try next? thanks __________________ Andy Mylin 1987 Pontiac trans am 2441 I/SA

07-15-2015, 01:09 AM	#2
HandOverFist VIP Member Join Date: Oct 2013 Location: Gulf Breeze, FL Posts: 1,651 Likes: 8 Liked 33 Times in 16 Posts	Re: 82-92 F body brake help Four piston on the front? Add four pistons to the rear and it will hold just about anything you throw at it. Two-step helps a bit also. __________________ Rich Taylor I/SA - 321

07-15-2015, 07:48 AM	#3
rod butcher Member Join Date: Dec 2005 Posts: 252 Likes: 297 Liked 132 Times in 27 Posts	Re: 82-92 F body brake help Check brake pressure front and rear. It should be above 1000 - 1200 psi. The rear brakes hold the car. We used to use extra thick shoes and uncut drums in the old days to hold it on the line. Now a dual caliper set-up in the rear is the norm. Our small block car holds at 3400 on 2 step with 4 wheel disc.

07-15-2015, 06:12 PM	#4
Lee Valentine Senior Member Join Date: May 2004 Location: Brookfield, CT Posts: 708 Likes: 13 Liked 319 Times in 68 Posts	Re: 82-92 F body brake help Have an 87 came to Ply. Violate master cylinder stock brakes front and rear holds at 3200 no problem.Foot braking or 2 step. __________________ Lee Valentine 1661 STK

07-15-2015, 08:46 PM	#5
Jim Whitehead Member Join Date: Mar 2003 Location: MA. Posts: 287 Likes: 153 Liked 150 Times in 41 Posts	Re: 82-92 F body brake help Rear brakes out of adjustment. I have 86 F-Body 305 stocker can hold at 3500 no problem. Front disc rear drum. Buy two sets of rear brake shoes use all four of the big shoes. Resurface drums for smooth and even contact.

07-20-2015, 10:14 AM	#7
Nick_Siebert Junior Member Join Date: Jul 2007 Location: Wamego, KS Posts: 38 Likes: 55 Liked 51 Times in 11 Posts	Re: 82-92 F body brake help Do yourself a favor and buy yourself a set of Strange, MW, or Lamb front brakes instead. I went through the same problems in the same style car with Aerospace, they told me it was all kinds of things causing problems and I finally got fed up and ordered a new set of Strange brakes, fixed all of them immediately.

07-20-2015, 06:06 PM	#8
Signman Senior Member Join Date: Oct 2003 Location: Lower Slower Delaware Posts: 535 Likes: 22 Liked 269 Times in 99 Posts	Re: 82-92 F body brake help Wilwood MC 260-4893 1 1/16 in. bore The 1 1/8 bore is recommended but makes the pedal really hard and you will have to put some leg in it. The smaller bore makes the pedal a little spongy and better feel at different RPM. Step down really hard and you will be late. Run Aerospace on all four and can hold to 3500. __________________ Frank Ferrucci I/SA 1271 "Be Thankful for the Gifts You are Given"

07-22-2015, 12:11 PM	#9
brian schuetta Member Join Date: Apr 2005 Location: san antonio tx Posts: 259 Likes: 5 Liked 28 Times in 15 Posts	Re: 82-92 F body brake help Did you drill the hole for the Clevis to attach to the brake pedal lever higher than stock? These cars never had two holes drilled in the pedal lever like older ones that came with manual and power brakes. I drilled mine around an inch or so higher, copied a 69' Camaro dimension. I used four primary shoes and I think 7/8" or 1" brake cylinders from a 69' station wagon.