Need info on Jeep MC

[Richard]

Could someone with access to Jeep service manual check something for me?

I just got a 95 4.0L YJ brake master cylinder and want to verify the port plumbing. Is the rear 10mm port for front brakes and the front 12mm port for the rear like earlier YJs? Just seems strange that the larger port is for the rear.

 

[J33P]

Isn't there just 1 to the rear? MY TJ is like that, 1 line runs to the T on the axle tube.

 

[Richard]

The MC has a single port for each. They're supposed to go to a combo block which then splits the front.

 

[dwcjwerfner]

Richard are the lines 2 different sizes? Or just the nuts?

Dwayne

 

[Baja]

On mine (93 XJ) the nuts were different sizes but the lines were the same. I just cant remember which one was the rear.

 

[dwcjwerfner]

Yeah that is sort of my point, is there really that much more pressue on one line than the other that it needs a bigger nut? Maybe the discs on the front would make create more pressure? I don't see that, I figure that being that the same booster is powering a similar port on the MC that the pressures should be equal. Any mechanics that know different want to correct me? So if this is the case it should not matter which port you plug into.

Dwayne

 

[Richard]

I don't know about the lines on a 95, I'm putting this in my '89 with 3/16" lines everywhere. The nuts are different and this is likely to ensure they go to the right brakes, so there must be a reason for it.

All Jeep M/Cs I've seen have the front port going to the back brakes and vice versa, so that's what I did yesterday and it worked somewhat, though I'm still having issues including a brand new M/C leaking into the booster that I have to replace :banghead:

 

[Richard]

And BTW, 95 was the only year with this MC, it has a plastic reservoir and mates to a dual diaphram booster.