Inconsistant Brake Fade

1971 Jeep CJ5
225 V6, all drums, stock axles

For the first couple times I press the brake, the jeep catches just fine, but if it's held down for more than a few seconds it'll almost sink to the floor. We can't find any fluid squirting anywhere or soaking the inner drums. But havn't pulled off the reservoir cover cause that's the biggest pain in the bootarski. The jeep does occasionally pull to one side or the other, but I figured that was just mis adjustment of the front brakes and having the hweel just slightly turned (huge amounts of play)

 

Most likely it is your master cyclinder. That stock stuff can only last so long. I had the same problem and reworked the whole brake system. Ended up changing the master cyclinder last after it completely blew out on the trail.

 

Ha ha I know about the pain in the butt-rooskie. R) But pull it and verify proper fluid level anyway. BTW using a small screwdriver for leverage via the access plate in the floorboard is the best way I know of to get the clamp-thing off.

 

I had the same problem. Pull up to a stop light and get on the brake. The brake would hold for a minute then just sink to the floor. It was the master cylinder. I got a new one from Krage for around $100.00 (I think). Installed it in about an hour but I'm sure others could have done it much quicker.

 

you can get a master cylinder from auto zone for alot cheaper. it dosen't look like the origal but it works just fine.. have one in my '71 for 2 years and has not given me any trouble.

 

Been running a 72-76 MC for three years with no problems. 22$ Rebuilt from GI Joes. Needed a couple of fittings to convert line sizes(can't remember what they were). Total cost about 25$