Questions on 96 booster mc swap

[1989 comanche mj]

Ive done the searches and read the write ups.  I have a 96 xj parts truck and grabbed the booster spacer master cylinder and prop valve.  The spacer is aluminum by the way, I know there was some discussion about it.

 

My questions are (Application will be my 92 comanche)

 

Does the pedal end need to be modified shaped or ground?  I saw on the writeup he did, but not sure if he was using a different rod.

 

Are the lines from the master cylinder into the prop valve bubble flared or standard flared?  I read they were bubble flared at the mc, but not sure about downstream.   I am using the prop valve from a 98 grand cherokee with 4 wheel discs, because I have the ford rear in there.  It works great.

 

Also, does anyone know if this booster will work on a 94 YJ?  My wrangler has the ford rear also, and the brakes are terrible on it.  It doesn't have the 4 wheel disc prop valve though.

 

Also, how can I post pictures?

[Incommando]

Pics have to be hosted like on Photobucket or such.

[cruiser54]

No mod needed to the rod. No need to swap prop valve. 

[1989 comanche mj]

Cruiser54, you have a explorer 8.8 disc rear in one of your trucks?  I have swapped these rears into 6 trucks and the brakes always work better with the 4 wheel disc prop valve.

[Eagle]

Cruiser54, you have a explorer 8.8 disc rear in one of your trucks?  I have swapped these rears into 6 trucks and the brakes always work better with the 4 wheel disc prop valve.

 

The Comanche front combination valve has NO proportioning function in it. All proportioning is taken care of by the rear, height-sensing valve. That should be readjusted if converting to disc brakes.

 

Putting an actual proportioning valve in the front will only reduce the braking force to the rear, and it has no provision for the bypass line so if you change the front combination valve to a proportioning valve, you have to abandon the height sensing proportioning valve.

[1989 Eliminator]

Check out my DIY booster swap in my signature. It outlines which ends are bubble and standard flared.

[cruiser54]

MJ is a different duck with the load sensing valve.

 

On my XJ with rear discs, I just swapped the guts of the prop valve from the same zJ I got the rear discs from. 

 

On the MJ it is more complicated, On the one with drum rears, I eliminated the load sensing valve and the prop valve. Ran the lines for the front brakes in a T. Figured out which real line went to the rear brakes themselves and used an adjustable prop valve. 

 

The MJ with discs on the rear, I've done the same except I haven't installed the adjustable prop valve into the rear line yet.

[1989 comanche mj]

Cruiser54, On my 92 with the disc explorer rear I eliminated the height valve in the rear and ran a single new line back.   Along with the 98zj 4 wheel disc prop valve.  It stops good, but has 35 inch tires on steel wheels so it could probably stop better.

[cruiser54]

Cruiser54, On my 92 with the disc explorer rear I eliminated the height valve in the rear and ran a single new line back.   Along with the 98zj 4 wheel disc prop valve.  It stops good, but has 35 inch tires on steel wheels so it could probably stop better.

Sounds like a decent setup.