I don't think that my mechanic knows what he is talking about BRAKE PROBLEMS!!!

[natedog437]

I have been having brake problems for the longest time. Everything has been replaced on my brake system like my master cylinder, pads, rotors, etc. There is still no pedal. There is no air in the lines and the car will stop, but it is only seconds after it has been on the floor. I thought it may be the brake booster, but my mechanic is saying the master cylinder is fine and it isn't my brake booster, it's the combination valve which consists of a metering valve, a differential switch and a proportioning valve. He is telling me that it is bad because I'm not getting any rear caliper braking. Could he be correct? The pedal feels completely mushy till it hits the floor and then has enough pressure to stop, the master cylinder that he put on has been tested and is good, and there is no air in the lines. Please help!

[InsanityInc]

The MC is probably adjusted wrong.

[NISTECH]

Test his theroy. pull the ebrake up to hold the car and apply the rear brakes. how does the pedal feel now? If the ebrake doesnt hold the car repetativly pull up on it till it holds the car and you can do this test.

[natedog437]

Test his theroy. pull the ebrake up to hold the car and apply the rear brakes. how does the pedal feel now? If the ebrake doesnt hold the car repetativly pull up on it till it holds the car and you can do this test.

I did the test and I think that I don't have any rear brakes! When I pull up the ebrake, it holds them, but when it is engaged it is still mushy. It doesn't start getting tight though till up at the top and my friends ebrake starts getting tight after about 2 clicks on his 240. I'll pull the ebrake up and down a few times then leave it up and push the brake bedal and it is still mushy. What does this mean?

Test his theroy. pull the ebrake up to hold the car and apply the rear brakes. how does the pedal feel now? If the ebrake doesnt hold the car repetativly pull up on it till it holds the car and you can do this test.

[180fan]

The ebrake being on, does it effect the pedal feel at all? I thought the ebrake works mechanically rather than hydraulically. You can adjust the ebrake with the adjuster nut at the bottom of the ebrake handle.

If the proportioning valves are bad, then replace your master. They're in there. Do you have any kinks in the rubber lines that could be keeping air in? Or did you check your bleeders to see if they're slowly seeping fluid out?

[natedog437]

It doesn't affect the pedal feel at all. It still feels mushy.If the proportioning valves were bad, would the master cylinder still be reading good pressure when tested?

[NISTECH]

Can you pump your brakes and build pedal pressure?

How did he pressure test the master??