Soft brakes almost to the floor on my 87 Camaro. - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

jbander · 07-18-2020, 02:02 PM

The system has been bled twice, Rear drum brakes have been adjusted(front has Disk brakes) Boost has been checked (holds pressure), check valve Ok. Push rod adjusted. New master cylinder. Bench bled the master cylinder checked out the proportioning valve(combination) , No leaks, Clear fluid. I put on the brakes to stop and the peddle goes down slowly to almost totally to the floor. I'm going to double check the new master cylinder tomorrow . Any thoughts on this any suggestions. Thanks everyone.

102SS · 07-18-2020, 02:22 PM

How is your manifold vacuum?

Is the vac hose from the booster to the manifold cracked?

George-CZ · 07-18-2020, 03:14 PM

The problem will be inside the brake cylinder.
I'd bet on a damaged rubber band.

I would take out the brake cylinder, disassemble it and reseal it.
...with the help of new rubber bands, of course.

Black_SS10 · 07-18-2020, 09:31 PM

master cylinder is leaking internally.

Sparko · 07-18-2020, 10:10 PM

I've bought "new" master cylinders for older vehicles before that were defective. Idk if they dry rot on the shelf or of it was sold as new but was a crapily rebuilt one. That would be where I start since it does seem like a leak-by.

07-18-2020, 02:02 PM	#1
jbander Drives: 1987 Camaro Join Date: Apr 2019 Location: Minnesota Posts: 14	Soft brakes almost to the floor on my 87 Camaro. The system has been bled twice, Rear drum brakes have been adjusted(front has Disk brakes) Boost has been checked (holds pressure), check valve Ok. Push rod adjusted. New master cylinder. Bench bled the master cylinder checked out the proportioning valve(combination) , No leaks, Clear fluid. I put on the brakes to stop and the peddle goes down slowly to almost totally to the floor. I'm going to double check the new master cylinder tomorrow . Any thoughts on this any suggestions. Thanks everyone.

07-18-2020, 02:22 PM	#2
102SS waiting at the tree Drives: SIM 2010 2SS/RS A6 Join Date: Apr 2013 Location: Niagara Falls Posts: 3,135	How is your manifold vacuum? Is the vac hose from the booster to the manifold cracked? __________________ 2010 2SS/RS A6 ZL1 Rims 60ft 2.03 13.08 at 107.82 (4/28) 2009 Pontiac G8 3.6L the DD

07-18-2020, 09:31 PM	#4
Black_SS10 SomeguyK Drives: 2010 Black 2SS/RS Join Date: Nov 2014 Location: FL Posts: 1,947	master cylinder is leaking internally. __________________ TMS 427, Dart iron Block, Forged assembly, Frankenstien heads, AGP TT 62/62 BB turbo's, AGP/Fore triple fuel system, Tilton clutch, Holley 1 7/8 shorties, Technostalgia tail lights,Oracle, Aeroforce, MGW shifter,Flowmaster, Pegasus subframe bushings,BMR trailing & toe arms,Z28 UCA bushings,Zl1 rear sway bar,Prothane,BMR,Goodridge brake lines,Ridetech HQ coilovers,3.91,Trutrac,billet caps,DSS axles,HE offest,built TR6060,1LE diffuser,Havoc spoiler,SSclones,20in MRR 017, Pirelli P Zero, Nitto NT555RII More to come.

07-18-2020, 10:10 PM	#5
Sparko Drives: 2010 Camaro 2SS Join Date: May 2019 Location: Rochester, NY Posts: 152 View My Garage	I've bought "new" master cylinders for older vehicles before that were defective. Idk if they dry rot on the shelf or of it was sold as new but was a crapily rebuilt one. That would be where I start since it does seem like a leak-by. __________________ 2010 Camaro 2SS 2018 Charger GT+ 2005 Cavailer LS S/C - Sold '87 HD FXRT - Wrecked pending repair

07-18-2020, 03:14 PM	#3
George-CZ Drives: 2010 2SS LS3 and 1978 STROKER 383 Join Date: Feb 2018 Location: Czech Republic Posts: 1,592	The problem will be inside the brake cylinder. I'd bet on a damaged rubber band. I would take out the brake cylinder, disassemble it and reseal it. ...with the help of new rubber bands, of course.