91 abs to 96 booster

We did the swap, everything went well, in was a direct bolt in. only big trouble was flaring the lines. Got everything tighten up bled the pee out of it, still not happy with the pedel travel. Does the paportional valve have to be straight? to get the booster in we bent it over almost to a 45 degree angle. Would this have any effect? That was great info a few weeks ago about this cause the abs was going out. thanks

at an angle, i would be worried that you could get an air bubble(s) trapped at the highest point. maybe thats the problem with the travel of the pedal?

im lookin at doing this swap is it a hard thing to do?

I did the same swap a year ago...wasn't happy w/ the pedal feel either. It wasn't as strong as I expected - everyone said you'd be able to lock up the tires at 50mph if you wanted - I'd be lucky if I could lock them up at 10. My '97s brakes are far better than the swapped in '91.

As far as it being hard - no, not too bad. It takes awhile though. Just take your time - be extra thorough - it is your brakes afterall.

I did this, swapping everything from the donor = booster, mastercylinder, portioning valve, and brake pedal assembly. I don't get what you are talking about having the portioning valve at an angle? It stayed attached to the master cylinder and went in just like the donor.

I found the brake pedal assembly to be different between the 2 vehicles, AND installing the late model non-ABS assembly was necessary to allow full travel on the the new booster rod.

Fantastic brakes with this running 31" tires and lots of extra weight. . .

Thanks for the come back. There was no portioning valve on the master, the booster was going to rub on the p-valve so i just bent the lines toward the motor. actually when i hook up the system the master started to leak out the back, put on a new one. Is the p-valve different from the 91 abs to the 96? i can lock the brakes up at 50 but have much pedal travel!

Triple4x4 said:

Thanks for the come back. There was no portioning valve on the master, the booster was going to rub on the p-valve so i just bent the lines toward the motor. actually when i hook up the system the master started to leak out the back, put on a new one. Is the p-valve different from the 91 abs to the 96? i can lock the brakes up at 50 but have much pedal travel!

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It's been years since I swapped it out, and I can't recall if the portioning valve was different but, it seems like it was. What I remember being a specific issue was the brake pedal assembly. The booster rod reaches through the fire wall. . . The pin that it fits onto on the brake pedal lever was in a different place on the two systems. . . had I not switched out (or modified) the brake pedal assembly, the original ABS pedal assembly would not have pushed correctly on the booster - sorry no pics but, I hope this makes sense.

The 91 era ABS also takes a smaller brake cylinder than non-abs so I swapped those out too. . .

Another option if you dont want to keep ABS is a WJ booster and master cylinder.

thanks 3X that makes a ton of sence, going to change it all out. the 91 is a daily driver. got an 86 mj that i will use the wj in.