richrex11

My front passenger tire locks up! Generally this is a good thing, except its the only one that does.

I have a 91 laredo, with the awesome bendix9, so i went and grabbed a brake booster, master cylinder and prop valve off a 97 cherokee... mostly a perfect fit, i was stoked on that!

made sure all my lines went to the correct locations on the p.v. and now for whatever reason my front passenger tire locks up under slight braking.
the stopping power is easily doubled from what i had before, so that is a plus.

The down side is I just took it down a dirt road at about 20-25 mph and stepped on the brakes to get a feel for it, the front right dug in and the whole rear end slid out to the left and actually spun me around 180 degrees.
Normally I wouldn't mind but there will be snow and ice soon and I drive daily with my 3 year old son, and the last thing I want to do is spin out uncontrollably...

Any thoughts or tips? anything I should look over? or anything I missed when swapping the brakes?

any help is greatly appreciated.
thanks in advance

BuckB91XJ

Sounds to me like your problem is more likely a bad caliper than a bad master cylinder.

richrex11

i was thinking it was possibly that... thats really the only thing i could think of being that only that wheel grabs so hard...

is it possible that i got the lines coming off the prop valve wrong? like the one that i have now going to the fr. passenger wheel is meant for the back? thats why there is more pressure?

Disoriented Hillbilly

I have the same junk system in the same year rig. Do yourself and your kid (i have three boys i tote around in mine) and get new calipers, pads, shoes, cylinders, & springs for your rig. Even if his isn't the prob (but my guess would be it is-i had a front pass caliper locking), you really should do this for safety's sake and peace of mind.

Now, if you can come help me do my swap out......... O.o

What all did u have to get to do the swap since its fresh in your mind?

richrex11

appreciate the replies guys... i got it fixed!

It was the prop valve, had the passenger side and the rear lines switched which was putting waaaaayy to much pressure on that side. On my way home today it actually seized up completely. Thankfully i was by myself and was able to pull off the highway. Not good going 60 and feel everything pull to the right then just stop all together... and boy that was alot of smoke! ha

so i did take your advice and got myself a whole new setup, calipers, pads... and of course having the prop valve feed the correct lines definitely helped out too.

The swap itself was pretty straight forward actually. Get a good donor, I actually went to pick-n-pull on a random day. Just so happened to be half off day, so things were looking good already.
Found a '97 xj that looked like it just rolled on the yard, literally... the roof was smashed! it only had 54xxx on it even.

Anyhow got the booster, master and prop valve off that unlucky jeep for $25! i was stoked, still am really. The swap was fairly smooth, biggest thing is just take your time and make sure you know which lines are going where... And looking at other jeeps, doesn't help.

The prop valve on my '91 w/abs, my neighbors '91 w/o abs, my buddies '94 w/o abs and another friends '96 w/o abs all look like an identical piece, however each of there lines are being fed in different ways. its lame, i know.

but aside from the parts i pulled from the junkyard, the only other things i needed was a flaring tool(borrowed from a bud) and a tubing bender(bought a lil one at kragen/o'rielly for $3), and a grinder to give me a little more clearance down by the peddle. The pushrod on the stock abs unit and the new replacement are about an inch off. The donor is longer, if you're handy you can chop an inch or so out of the middle and tack weld it back together.
I, on the other hand, am not so I just modified the brake bracket a little for the extra clearance. it works.
Thats it really as far as parts go. I wish I would have taken pics along the way, but it really is a bolt on process...

Pull out all the abs crap, the computer is under the back seat, a couple fuses here and there, and the motors on the passenger side as well as the high pressure ball and the crappy master/booster/pv combo that the abs uses.

bolt the new one in...it uses the stock holes, no drilling is required and everything should clear fine, take the airbox and washer reservoir out of the way to give you some room to work. Bend up your lines and screw them back in and bleed your system. thats it...

before i did all this i checked all over the place for some "how-to's" and found some really really good ones that gave me the confidence to tackle this and i'm glad i did! its sooooo worth it. i'll find the links and put them up for you.

Disoriented Hillbilly

Thx bro.
Good lookin out. Will have to do this soon. Jeeps bday is comin up soon. Been a year already! They grow up soooooo fast! He wants a winch (thinks hes 20!), but alas-i believe he will have to settle for a new muffler and hi flo cat instead. Come to think of it, my rig is 20. Actually 21 being they came out year before. Eh, Jeeps these days. What do they know.

richrex11

so i looked again, this guy on here did this write-up and it was the one i followed actually... pretty much spot on. there are some others out there, but this is by far the most comprehensive.

Good luck with the swap!

https://www.cherokeeforum.com/f2/con...r-brakes-1631/