Right right see that now - so far the worst part of the swap has been the lines crossing behind the engine and fishing them out. I disconnected one line on the drivers side and the entire reservoir emptied out the open tube on the passenger side, ran down the engine bay and found its way down my LCA. Luckily I put a whole bunch of rubber mats down in my garage before starting this project in anticipation of that
LKN, that is the high pressure pump that supplies the accumulator with high pressure brake fluid. This is also the part that wears out and has the lifetime warranty on it.
On further research and trial and error, when you do the 1995-1996 upgrade to a 1991-1994 XJ with ABS, you must also replace the brake pedal just like what was stated in the write up by Steve Ward posted by Green Mesa. The reasoning behind this is that the ABS master cylinder is installed at 90 degrees to the fire wall and the 1995-1996 power brake booster is installed at a slight downward angle. This causes the pin that the power booster shaft hooks to on the pedal to be approximately about a little more than an inch lower on the brake pedal assembly. If you look at my post #112, you can see where the original pin location was (the upper hole)and where I had to move it to(the lower weld).
Yes, there is enough flex in the power booster shaft to make it fit onto the higher pin on the original ABS brake pedal assembly, but you will be forcing the shaft into the power booster on an angle and it will eventually destroy the power booster. Don't ask me how I know. You might get away with it for a while, but it will fail. Find a 1995-1996 brake pedal at a local junk yard, it's easy to replace. Or you could move the pin if you can fab, but it would be safer with a factory brake pedal.
Hello warlock thanks for chiming in appreciate it. My predicament is now that the guy that help me with adjusting the booster Rod all the way in because he said it was touching a inside the master cylinder now I have brake softness. So where do I adjust out my brake pin? From what I've read it's supposed to have a .20 Gap between the master cylinder Cup and the PIN any opinions would be appreciated.PITA
Hello warlock thanks for chiming in appreciate it. My predicament is now that the guy that help me with adjusting the booster Rod all the way in because he said it was touching a inside the master cylinder now I have brake softness. So where do I adjust out my brake pin? From what I've read it's supposed to have a .20 Gap between the master cylinder Cup and the PIN any opinions would be appreciated.PITA
I did not swap out the pedal could that be my problem? at 20 miles per hour it takes about 2 car lengths to stop not good! I bled the system with about 2 quarts of brake fluid never could get the lines to run all the way clear though using the power assisted bleeding system!
Agree with Green Mesa. If the swap details are good, that's about the only thing other than a leak. And you would know if you had that.
It's ironic you posted about this today. I just started researching again on this topic last night and plan on starting to rip into mine today.
Green Mesa I have a 91 and my brake light switch looks like the pic posted earlier. I won't have a need to drill out or notch the end of the brake pedal rod to make it work and it doesn't sound like Pezman needed to either.
Sounds like we're going to have to swap the brake pedal too. Wonder if the pin the rod connects to being in the incorrect location is preventing the rod from moving a full stroke. If the brake pedal angles outward toward the back of the jeep, moving it up would indeed cause more stroke.
So here's where I'm at, and I'm stuck. It seems this cube looking box is attached to the metal bracket with the 4 studs going through the firewall. It's buried down in a pocket in the wheel well, and it's in a bind. I can't get it out or the bracket off.
Any words from the wise here? I had to take the master off to get this far.
That sucks. Can you get the four bolts off from inside the firewall? Or is it a hidden bolt holding you up? I've been going through the pics in the thread and can't really tell if there are extra bolts towards the fenderwall
Here's a picture I grabbed from the web. It looks like there is a bolt holding the bracket to that box (pressure modulator I think). I have absolutely no clue how Jeep assembled this or how this guy in this pic got it out in one piece.
Pezman, Yes, you should change to the 1995-1996 brake pedal.
I think your buddy adjusted the booster shaft to short. Here's how to adjust the booster to MC shaft:
1-Pull the master cylinder off of the power booster.
2-Adjust the adjuster on the end of the booster shaft to make the shaft longer (turn nut on shaft counter clockwise I think. Check it to see whichever way makes it longer. I used a pair of bent end needle nose pliers to hold the lower end of the shaft so it doesn't spin and a small socket on the adjuster).
3-Take the master cylinder and slowly install back onto the booster by hand only, do not use the nuts and don't push hard. You are looking to feel when the master cylinder contacts the shaft. If you lengthened the booster shaft long enough, you will notice that the master cylinder contacts the shaft before the MC housing contacts the booster housing. You should see a space between the MC and the booster while looking at the assembly from the side.
4-At this point, using trial and error, start adjusting the shaft shorter (go a little at a time) until the MC body contacts the booster housing. Make sure that the two housings are touching solidly and completely bottomed out. When you get to the point where the MC touches the shaft and booster housing at the same time (without forcing it), shorten the shaft 1/2 of a turn shorter.
5-Your shaft will be correctly adjusted.
6-Put everything back together
7-Also, I highly recommend getting and installing that spacer that goes in between the booster and firewall. There is a chance that since you are not currently using it, there could be a small amount of preload on the input shaft of the booster and that could be adding to the problems with your brake system. There is a reason the factory used that spacer.
LKN, Don't even bother trying to separate the "box" from the bracket with the four studs that go through the firewall. You need to remove the 4 nuts from the inside of the passenger compartment, the ones near the brake pedal. Then pull that whole assembly out of the engine compartment. Hold onto all the nuts and bolts to reuse on the new booster.
Even if you are buying the Master cylinder and booster from an auto parts store, I highly recommend getting the spacer and the brake pedal from a donor vehicle at a junk yard. I did this swap and my brakes work excellent.
On a side note, I used that bracket that the high pressure pump used to hang from to mount my relocated vacuum canister that used to be mounted behind the right side of the front bumper.
LKN, Don't even bother trying to separate the "box" from the bracket with the four studs that go through the firewall. You need to remove the 4 nuts from the inside of the passenger compartment, the ones near the brake pedal. Then pull that whole assembly out of the engine compartment. Hold onto all the nuts and bolts to reuse on the new booster.
Even if you are buying the Master cylinder and booster from an auto parts store, I highly recommend getting the spacer and the brake pedal from a donor vehicle at a junk yard. I did this swap and my brakes work excellent.
On a side note, I used that bracket that the high pressure pump used to hang from to mount my relocated vacuum canister that used to be mounted behind the right side of the front bumper.
Yeah - to clarify I was able to get it out, but only after I removed one of the bolts holding the bracket to the modulator. It wasn't budging otherwise. Wasn't enough clearance between the wheel well and the firewall to get the studs going through the firewall to clear.
Also, the spacer you're referring to is the thin white foam sheet? It's more of a gasket in my case. Is there a thicker spacer on the donor? I don't recall that when I pulled the booster from the JY.
Yeah, there is an aluminum spacer between the booster and that gasket. I'm not using mine and the brakes are good but maybe they would be more solid if I did. My concern was that I would lose that much more pedal travel and they are soft enough that I could use all the travel I can get.
Okay thanks Warlock. so definitely get the spacer, what is that about 3/8 of an inch? Or smaller? Basically get it from a 95 or 96 donor? Cuz I'm at wits end with this soft pedal so I'm going to the junkyard Saturday and I will ask for the spacer also.
