check master cylinder... may need to bleeed the brakes (purge air from the lines) i notice my sister's jeep brakes felt spongy today and just topped of the m.c. will topped it off as far as topping a m.c. off goes. which is NEVER FULL! never fill to the top, there is a line on the side.

 

hi there i was thinking on how can i fix the brakes on my jeep it worn the disc brake pads. what is the real problem of it? please help me with this. thanks a lot.

 

Having more or less brake fluid wont correct a brake issue (unless it's empty). As long as there is fluid in the line, they will work identically each time. Now, if the brake fluid is old then it's likely been absorbing moisture (that's what brake fluid does) and should probably be bled off, a full system bleed. Moisture doesn't compress, brake fluid does.

If you are experiencing this locking up/squishing problem frequently it could be the rear linings. Does it only do it when it's been sitting, and/or it's damp outside. Shoes get temperamental in damp situations then relax a bit once they are warmed up. The next option would be a faulty wheel cylinder. The master cylinder may be failing. A master cylinder is basically a piston pushing the fluid to the calipers and wheel cylinders. The piston has seals around it, and when they begin to leak you get the feeling of the pedal going to the floor with no braking. This is due to fluid bypassing the seals, therefore the piston moves but doesn't push the fluid. Then when it engages, there is built up pressure which immediately applies fluid pressure. I do believe the proportioning valve is built into the master cylinder too. The proportioning valve sends the proper pressures to the front and rear brakes. If the pressure is modified, you may be getting too much pressure to the rear brakes, forcing them to lock up.

First suggestion would be to bleed off the entire system. That should be the cheapest. Check the rear brakes to learn if a wheel cylinder is leaking. The next step would probably be to replace the master cylinder.

This is a long shot, but if the parking brake system isn't properly adjusted, it may cause what you're experiencing due to the linings being very close to the drum. That essentially means that they barely move before they are fully engaged.

Keep us posted as to how it's reacting, or if you take any actions that seem to help, or don't help.

 

Hey, I also have a 04' Colorado. My brake pedal felt really stiff one day, and before I knew it, I could smell my brakes burning. I had it towed to a brake shop where I know the owner. His mechanic looked it at, and all four brakes were locked. Then out of nowhere, the brakes unlocked and were fine, and I drove it out that day. The next day, I drove it everywhere I needed to go, and on the way home I felt the brake pedal getting stiff again, and yet again, my brakes started to smoke. I pulled over and had it towed to a chevy service department. I heard that the problem could be an ABS sensor, but my ABS light has never come on, nor was my check engine light on. It has been 2 days, and chevy has not come up with a diagnosis. Any ideas on what this problem could be? If you have any ideas, could you give me an estimate of what you would think it would cost tyo fix? I just want to know if this service department is trying to rip me off, just because I have never taken my truck to this chevy service department, and I do not know anybody that works there.

Thanks,
Andrew.