wildspear

93 ZJ, 4.0L I-6, trans?, transfer?

I just bought my ZJ and havent looked it over very much. The brakes are bad, pedal to the floor (motor running or not) with no brakeing power at all. Fluids are good, pads and rotors are good, PO changed the master about a month or so ago. From the little bit of details I've provided what should I be looking at? booster?

freegdr

another master if booster is bad brake pedal will be very hard not soft ,leaking fluid

wildspear

He said the master was a "reman" and not new. So it could be a bad master then. Thanks.

Bustedback

I would try bleeding the system, the PO may not have done a good job of bench bleeding the master before installing it.

wildspear

Hey broke the bleeder valve and couldn't bench bleed it. He bleed it after it was installed on the rig. Is it possible that it didn't receive a good bleed and that could be causing my issues?

kojoff

YES YES YES.

wildspear

I took a quick look at the master today but I didn't notice any bleeder or any broken bleeder. I did notice that the fluid was down, so I filled it and started pumping the brakes. I got resistance with the pedal, I started it up and no resistance. I checked the fluid and it was down some, I filled it. This went on about five or six times.

Now I have resistance at the pedal when the rig is turn on, and the rig will stop now. Very good!!! The pedal still goes about half way to floor but it will stop the rig on a dime.

I haven't bleed anything (got distracted by all the other things this jeep needs to have done) today. Is the pedal going half way to the floor an issue? Should I still bleed the brakes to make sure all my bases are covered?

The brake light was on but now it's off.

wildspear

Sorry to bring this thread back.
The fluid is gone from the resivor, I looked around and noticed "bubbled paint" on the booster under the master. I seem to have a leak where the master connects to the booster. Bad seal, I would assume. Is this seal replaceable? Is there a way to test the booster to make sure it is still good?

razor02097

All the booster does is make it easier to apply the pressure needed to stop the vehicle. It is pneumatic and not hydraulic. The master cylinder is the beginning of the hydraulic part and the wheel cylinders and calipers are the end.

If you are getting a brake fluid leak under the master cylinder then it is probably leaking from a defective seal. If it is leaking from one of the lines going to the proportioning valve then it is likely due to cross threading or a bad double flare on the line.

wildspear

I checked the master out, while I was poking around I notice the 2 large rubber hoses (sorry I don't know the exact name of the hoses) that go to the master were leaking where it attaches to the master. The OP never put the hose clamps back on after he replaced the master. I placed the clamps back on and I cleaned up the fluid, so we'll see if it continues to leak.

I did notice that while I have the GC running, and I apply pressure to the brake pedal, the RPM's increase. Is it suppose to do this? My Cherokee doesn't do this that I noticed.

Bustedback

Hose clamps on brake hoses? I'm scared now.

wildspear

LOL!! it's those darn clamps that you have to squeeze to loosen, they clamp the hose on each end going from the master cylinder to the ABS. I'll take the flames but I have no idea what those things are called.

freegdr

what he said x100

wildspear

Are you guys going to force me to post pics....? I'll do it, I will

Bustedback

I need pics.