YJ Master Cylinder

[redrock]

I have a 1988 jeep wrangler 33" tire and the brakes feel soft, I recently added disc brake conversion kit but they felt soft long before the kit.

My question is how do you know if the master cylinder is bad?

Thanks for your help

 

[1badweb]

i used a 2000 dodge ram 1500, then took the ears down a little with the dremel tool, it fit just fine. there are tons out there, just go get one from a savage yard or LKQ in springville and do some slight modifications.

 

[redrock]

Thank you

 

[Jinx]

As with any new master cylinder, I recommend bench bleeding the heck out of it...

It will amaze you how much air you will get out of it...

 

[Bobzilla]

I have a 1988 jeep wrangler 33" tire and the brakes feel soft, I recently added disc brake conversion kit but they felt soft long before the kit.

My question is how do you know if the master cylinder is bad?

Thanks for your help

If the brakes felt soft long before the disc brakes were installed, could be the master cylinder seals are pushing past the fluid in the master cylinder.
I have an ongoing issue on my 87 YJ disc brake conversion with Chevy D52 calipers on my rear axle. I removed the original 87 YJ master & single diaphragm booster and installed a 95 YJ dual diaphragm master & booster, I still have a soft pedal with to much pedal travel.
The 95 YJ master is a 1" bore for disc/drum rear brakes, because of the size of the calipers I'm using I need to go to a 1 1/8" or 1 1/4" bore master cylinder, so I ordered a 2001 F-150 4 wheel disc brake master, I have not received the part yet, when I install I will update, I will leave a link I used to help with my soft pedal issues, good luck.

home.4wire.com/erik/4runner/brakes

 

[redrock]

I upgraded my master cylinder, added one out of a 2000 1500 dodge. Had to do some small modifications to make it work. Also found I needed a new power booster. Definitely huge improvement, I still think the YJ stock brake pads are to small to stop the 33" tires and or bigger for that fact. This has been a learning experience for sure.