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03-21-2021, 01:14 PM | #1 |
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2002 F body brake pressure
I know this has been beat to death subject, but how much brake pressure do you need to hold a 2002 f body on the starting line. We have 4 piston aerospace on the front 4 piston strange on the rear. After 3 pumps we have 1000 psi on the rear. It seems to wants to pickup the front end and then slides the front tires. Do you think moving the rod up on the brake pedal would get more brake pressure? Or a larger bore on the master cly.? Thanks Tom
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Tom Meyer 5240 SS Stock ??? |
03-21-2021, 03:23 PM | #2 |
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Re: 2002 F body brake pressure
Couple of questions here. Which end is plumbed to which end of master cylinder? And where is the pressure gauge plumbed into?
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03-21-2021, 04:19 PM | #3 |
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Re: 2002 F body brake pressure
Rear brakes are on the front of the master and the pressure is taken at the bleeder on the rear caliper. The car when we got it had braided hose, we switched it to hard line. The car has good pedal and stopping it is no problem. Tom
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Tom Meyer 5240 SS Stock ??? |
03-21-2021, 06:10 PM | #4 |
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Re: 2002 F body brake pressure
Have you tried more pressure? Aerospace sells a pad that holds better, I got 400 rpm. I don’t know if the will fit the calipers you have, compare to your front pads. Some people do run dual rear calipers.
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03-22-2021, 09:41 AM | #5 |
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Re: 2002 F body brake pressure
1000 psi should be enough to hold it. Smaller bore master cylinder and moving the rod up will make the pedal easier and should allow more pressure.
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Jimmy "Cooter" Hidalgo, Jr. 4865 E/SA '04 GTO 4865 SS/GA '99 Firebird |
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03-22-2021, 11:02 AM | #6 |
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Re: 2002 F body brake pressure
Most of the probable issues have been mentioned .
Excessive hose length , bore size ect. Pedal ratio is very important , unless you're an Olympic weight lifter . Using a larger bore will give more volume but LESS pressure with the same pedal ratio and travel . With a 6 to 1 pedal ratio and a M/C bore of 1 1/16 to 1 3/32" you should be hitting at least 850-900 # on the first pedal hit . Have someone pump the pedal while you watch the calipers as they are applied and watch and feel for deflection or movement in the caliper itself and also the rotor. Proper alignment is extremely important with after market race brakes due to the light weight of the mounting brackets and light weight rotors . I've seen many brake issues cause by misaligned rear housing ends . Its especially a problem on older GM housing ends that are usually heavily rusted and warped. Any movement here will make it harder for the brakes to get a full ,positive hold .
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Tom Goldman 1500 SG , 1506 STK Last edited by Tom Goldman; 03-22-2021 at 11:04 AM. |
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03-22-2021, 01:35 PM | #7 |
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Re: 2002 F body brake pressure
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03-28-2021, 03:18 AM | #8 |
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Re: 2002 F body brake pressure
Tom My car was plumbed backwards initially causing excess pressure on the rear brakes. I bent the backing plates before I changed the lines around. Mine has front disc with drum rear. Hard to find good help
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03-28-2021, 08:09 PM | #9 |
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Re: 2002 F body brake pressure
Thanks for all the help. Tom
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Tom Meyer 5240 SS Stock ??? |
03-29-2021, 11:17 AM | #10 |
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Re: 2002 F body brake pressure
When we ran an automatic, we had dual rear caliper Mark Williams brakes (and MW in front as well) and would put about 750psi of brake pressure (on a gauge in the car) - and that would hold 43-4500rpm without issue. On the 2-step the car wouldn't move at all either in the front or the rear no matter how loose we had the front or rear shocks. The brakes held the car rock solid. I'm not sure about the master cylinder, but I assume it was whatever Mike Pustelny from MPR Race Cars would suggest.
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