Grand Cherokee Master Cylinder and Brake Booster Swap

[dellstopjeep]

have any pictures of where the shims would go as Im a little lost how I would do that???

 

[dellstopjeep]

You did not grind it in the same position as the stock one. I ran into this. You kind of only have one chance at it. I ended up installing a high pressure switch in the line of the master. it was only ten dollars.

high pressure switch? pictures of could ya explain as im a little confused on what i would buy

 

[roxj]

will this swap work on an 84 with the 2.8 v6 and auto

 

[bcmaxx]

high pressure switch? pictures of could ya explain as im a little confused on what i would buy

something like this:http://www.nextag.com/Brake-Light-Switch-71815910/prices-html?nxtg=26220a1c052e-2B90E535C78F2FA4
=

you'll need a tee as well

 

[dellstopjeep]

well today turned out somewhat successful, laid down a bead on the pedal rod then ground it down again, took a couple tries, I was real cautious but third time I got it dialed in. BTW, bleeding master in rig is a real real messy job. I was able to use the brake lines already on the master from the wj as they had flex lines attached which made them great for reusing. All thats left is bleeding brakes and realizing I did a horrible job bleeding the system!

 

[HKB3]

high pressure switch? pictures of could ya explain as im a little confused on what i would buy

best pic I could find on the web

I will be doing a 99WJ booster swap into my 87 MJ soon also swapping in a disk brake 8.8. Still doing my homework on the load sensitive prop valve in the rear and how to go about removing safely.(Mostly how to run the brake lines).

 

[yossarian19]

Is the WJ master cylinder different from the ZJ / 98 XJ master cylinder? I know the boosters are different but I keep running in to 1" bore on the MC between all 3 jeeps.
Just wondering if I can swap booster only and see an improvement...

 

[XJLI]

just did this on my 93- it was literally bolt in. the brake switch gets triggered by the pedal so i didnt have to modify the rod at all, and didnt use any spacers. hardest part was bending the lines and that goddamn rear proportioning valve fitting was a bitch to turn, had to borrow a crows foot wrench to get it tight enough not to leak. stopping power is INTENSE now, i drove down the block slammed on the brakes and locked up all 4 33s. my friend and i hit our heads on the dash first time testing the brakes.

definately worth it

 

[warlock4x4]

I just did this swap to get rid of the crappy ABS system in my 90 XJ. Now what has to be done to get rid of the "check ABS" light in the dash? Was thinking I could just pull the bulb, which requires taking the dash apart, but if there is an easier way I am open

Thanks
Chris

 

[XJLI]

hokay, another drive and my pedal is definitely too spongy... but not air in the system spongy... more like.. too much power booster spongy? might be a vacuum leak, it sounds like im stepping on a cat when i hit the brakes sometimes. i still have at least twice the stopping power as i used to. everyone else who did this has a firm pedal?

 

[bcmaxx]

hokay, another drive and my pedal is definitely too spongy... but not air in the system spongy... more like.. too much power booster spongy? might be a vacuum leak, it sounds like im stepping on a cat when i hit the brakes sometimes. i still have at least twice the stopping power as i used to. everyone else who did this has a firm pedal?

my pedal was,and is not firm, it does have some travel and a little spongieness. my first booster failed and would hiss on application, it was buggered. Put another booster in, and the brakes are great! I bled and re-bled the brakes to ensure there is no air in there.

 

[XJLI]

im probably gonna bleed them again tomorrow just to be sure, theres definitely no booster hiss, it literally sounds like a cat meowing :laugh:

the brakes are awesome but like you said, the pedal does have more travel.

 

[Jeepm@n]

Your stepping on a cat not the brakes. You should be nice to your pussycat. lol Anyway's it is the booster. I'm willing to bet it has a small leak.

 

[89xj]

I just did this swap to get rid of the crappy ABS system in my 90 XJ. Now what has to be done to get rid of the "check ABS" light in the dash? Was thinking I could just pull the bulb, which requires taking the dash apart, but if there is an easier way I am open

Thanks
Chris

on my 89 that i did the swap to, i had an empty spot in the fuse block for abs(because i dont have abs), if yours has a fuse in the fuse block, take out the fuse and see if the light goes out.

 

[warlock4x4]

on my 89 that i did the swap to, i had an empty spot in the fuse block for abs(because i dont have abs), if yours has a fuse in the fuse block, take out the fuse and see if the light goes out.

Thanks, did not think of that.

I drove it today after bleeding the brake twice and I to have a very spongey pedal. Goes almost to the floor. I will bleed them again tomarrow and see but this spogey pedal stuff does not seem right

 

[89xj]

Thanks, did not think of that.

I drove it today after bleeding the brake twice and I to have a very spongey pedal. Goes almost to the floor. I will bleed them again tomarrow and see but this spogey pedal stuff does not seem right

the pedal should not go to the floor. did you adjust the rear brakes/drums? if they are out of adjustment, you will get too much pedal travel.

 

[warlock4x4]

Well that was something I wsa thinking of today. So tomarrow I am bleedding them again (just to be sure) adjusting the rear brakes.

Thanks for the reply

 

[dodge90wood]

Thanks Starboard M

Web Wheeler
The write up was great I took your advice and bought a booster and m/c off of a 2000 grand cherokee. I still have to do the install but hoping that it will help. I had a question though do I need the proportioning valve that will accompany the booster or will the old xj valve do just fine?

 

[89xj]

Thanks Starboard M

Web Wheeler
The write up was great I took your advice and bought a booster and m/c off of a 2000 grand cherokee. I still have to do the install but hoping that it will help. I had a question though do I need the proportioning valve that will accompany the booster or will the old xj valve do just fine?

unless your going with rear disc brakes, you keep the xj proportioning valve when doing the wj swap. i kept the prop valve when i did the wj swap on my 89.

 

[warlock4x4]

How different are the prop valves. The one that came off the donor looks just like the one on my 90 with ABS. I still have a pedal that goes to the floor (well almost) after doing this swap.