Another Master Cylinder Question

I've been trying to get the brakes working on the CJ3A (single resevoir type master cylinder). While trying to bleed the brakes, there was no fluid getting to the rear wheel cylinders. I assumed it to be a master cylinder problem. I loosed the brake lines at the master cylinder and fluid pumps out of the front line outlet, but not from the rear outlet. Does this mean the master cylinder is bad or would a rebuild kit fix it? I assume I need a whole new one since I think the rebuild kits only replace the plunger, etc.

Jim

 

could be plugged
I'd take the fitting off and check it out

 

I've got a TJ home with the same problem. I threw out the master cylinder because it was dirty, and the proportioning block underneath it was plugged with crap as well. Blew it out with the compressor, and good to go, it's just sludge.

Paul

 

Did you try bench bleeding it first? You need to make sure ALL the air is out of the MC and that requires full compression of the plunger. The pedal may not allow a full stroke of the plunger. If you have access, try disconnecting the pedal and use a screwdriver or other tool to depress the MC plunger completely. If not then remove the MC and do it on the bench.

 

Thanks for the suggestions. I didn't realize the fitting comes off. I think I'm going to take it apart and see what conditions the parts and pieces are in. If the bore isn't too pitted, then I'll try rebuilding first.

Jim

 

you may have to replace those 2 copper washers as well
seems I can never get them to reseal after having had them off