Need help, master cylinder

Jonsey181 · #1 10-25-2009, 04:41 PM

I just purchased a cheapo junker 1989 cutlass supreme Int. series for $200 just a project car to fix up and sell, i replaced everything almost I can think of and the car is running in great shape, except the rear brakes. I can not get fluid to them! the front brakes I bleed and they work perfect, and the last thing I want to do is replace the master cylinder So can you guys give me some ideas of what could be wrong. When I looked at the back brakes the parking brake (which is broke) was hung up so I unlocked the back wheels manually, and im guessing since the parking brake says "pump to set" that it is hydraulic? could it have broke while it was set on and kept valves closed in the master cylinder not allowing fluid to move into the cables? I know the brake lines are not blocked seeing that I just replaced them, I am not sure the condition of the equalizer but I know fluid is not getting back there.... any help would be apprecietad thanks!

Jonsey181 · #2 10-25-2009, 05:44 PM

can anybody help me with this?

maxwedge · #3 10-26-2009, 06:42 PM

Pump to set just activates the internal actuator in the caliper it is not hydraulic, this brake system was troublesome from day one, there was a recall to replace the lower caliper slides with stainless steel replacements as they rusted and froze. The fluid goes thru the proportioning valve after the m/c, that could be bad. Try actuating the button on the end of the prop valve to see if fluid gets to the rear. What bleeding method are you using, if it is the vacuum pump type you will need to pull that button out.

Jonsey181 · #4 10-27-2009, 03:07 PM

Thanks for the response! the proportioner does have a busted bleeder on it, so I am thinking I will be getting a new one, but I still cant get fluid into the rear lines from the master cylinder any valves up there that could be stuck? this double resevoir on this cylinder has me confused... im a diesel guy aint seen them much! Im thinking im just gonna take the master cylinder apart and do some tinkering, anymore ideas? help is appreciated!

maxwedge · #5 10-27-2009, 06:39 PM

Crack the line to the rear brakes at the m/c see if fluid comes out then do the same at the prop see if fluid comes out under pressure, have someone step on the brake pedal of course.

marcel43 · #6 03-31-2010, 04:01 AM

Quote:

Originally Posted by maxwedge

Crack the line to the rear brakes at the m/c see if fluid comes out then do the same at the prop see if fluid comes out under pressure, have someone step on the brake pedal of course.

I'm having the same problems with my 96 cutlass. I believe the problem is in the brake module. I noticed that a very small ball bearing has wedged itself into one holes that distributes the fluid, and has stopped the flow. i dont think i can get out that ball bearing, its so small.

Looks like i'm getting a used brake module, hard to find. New is way too much. Hopefully this will resolve the problem.

marcel43 · #7 03-31-2010, 07:23 PM

Quote:

Originally Posted by marcel43

I'm having the same problems with my 96 cutlass. I believe the problem is in the brake module. I noticed that a very small ball bearing has wedged itself into one holes that distributes the fluid, and has stopped the flow. i dont think i can get out that ball bearing, its so small.

Looks like i'm getting a used brake module, hard to find. New is way too much. Hopefully this will resolve the problem.

*** my braking problem has been solved, I bought a used Master Cylinder and ABS Module together from an auto wreckers. It wasn't hard to change, I did it by myself. Two nuts (15mm or 5/8 socket) hold it on. I did have to get assistance in bleeding the brakes. The brakes are working great

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