1990 W350 brake problems

[ezcurra]

Hello,

I just bought a 1990 W350 truck. The brakes have some problems that I'm trying to diagnose.



The previous owner replaced the master cylinder and front brake calipers. After running fine for a while, he found the pedal to be low and a bit soft, and the ABS and BRAKE lights on the dash came on. From reading the manual, this could mean three things: Low vacuum, hydraulic problem (Imbalance F/R?) or that the parking brake is on. The fluid on the reservoir seems to be a bit low (on both ends), but there are no apparent leaks on the wheel cylinders or elsewhere I could see.

The truck stops fine and very powerfully, but the pedal continues to be low.

Any ideas?

Thanks,

Mikel

 

[dpuckett]

Has anything been done to the rear brakes? If they are out of adjustment, or getting worn on owrn drums, that will make your pedal a little low. Also, has all the old fluid been flushed out of the system? That, too, can make for mushy brakes. If that fails, check the pushrod length going into the master cylinder.



Daniel

 

[mysteryman]

you might like to read my posts on brakes. check them out