XJ rear disc conv=problem

[XJ-Vince]

I have a 91 XJ with no ABS. I aquired a 87 44 rear end with a disc conv. Being about the fourth owner I dont know the make of the conv. I'm guessing SSB. Any how I installed the rear end, plumbed the brakes and they're scary!!

The pedal is low and very front biased.

I played with the proportioning valve and took out one o-ring to by-pass the restrictor on the rear side to allow a little more volume to the rear. This helped a little.

I have installed a new oem master cyl. and bled them with a pressurized bleeder can. The system is air less after 1/2 gallon out each corner.

I think the booster is good. The pedal goes down when you start it.

I think I need a different master cyl. , with more volume,to the rear.

Step on the brakes - stop slowly, mostly all front
2-3 pumps - better
4 pumps- great
5-6 pumps- getting rear biased
pump it like crazy and the rear locks up

I talked to the guys at SSB and they said they had a master cyl that might fix it for $160.

I think there should be a good swap out there at a decent price, a parts store rebuild would be nice.

A ZJ master cyl maybe

What about mid 80's GM cars like the Firebird T/A with rear disc and no ABS?

sorry I'm so long winded , thought I would spit it all out at once.

Thanks in advance for any help.

[Dukes69]

Originally posted by XJ-Vince

I played with the proportioning valve and took out one o-ring to by-pass the restrictor on the rear side to allow a little more volume to the rear. This helped a little.

Just a thought, is it an adjustable proportioning valve your talking about? If not, you might need one, so you can adjust between front and rear. Wilwood makes a nice one, as do someother companies.
-Chris

[XJ-Vince]

Originally posted by Dukes69
Just a thought, is it an adjustable proportioning valve your talking about? If not, you might need one, so you can adjust between front and rear. Wilwood makes a nice one, as do someother companies.
-Chris

no, its the stock one

[Chris L]

Contact MJR {mike rollins} on this board. He has a lot of experience with XJ brake upgrades and is a jeep tech. He should be able to help.