Seizing front wheels after drive

[Roler]

Background: the xj has been sitting a lot the past year. Previous drive around the block, left wheel barely able to spin towards the end, wheel cap literally melted of the wheel, hanging on by some melted strings of plastic.

Rebuilt the calliper piston on that side. Already had replaced the rubber brakelines both sides before that.

Didn't get to drive it till yesterday (waiting for new alt). Test driving around the neighbourhood for 15 min, towards the end both front wheels severely dragging, like driving up a steep hill, only just made it back up the driveway.

Lifted the front thinking it must have been the right front wheel sticking since I had not done that piston yet. However both wheels minimal movement.

Let it cool for 2 hrs after which both wheels showed some movement again. It was dark outside and didn't crack the bleeders at the time to see if that would free them up.

So am I looking for a common 'denominator' for BOTH wheels seizing up now?
Would a bad master/proport valve cause this?
Rubber brake lines already replaced.
Doing the piston on the left side didn't prevent it from seizing up again.
Time for new calipers all together?

Ps: I have ALWAYS had a spongy break pedal.
Replaced master cylinder a few years ago without making a difference to it so swapped the OEM back in and returned it. Hissing sound when applying brake. But these are issues not related to the seizing brakes I think.


Appreciate your ideas or experiences with this
Cheers

[FARWEST]

Your on the money with the master cylinder or proportional valve 'sticking'...pressure isnt being released fully after braking....other thing to check is that the caliper pistons are free to return in the housing...brakes being brakes it is a simple hydraulic system...'somewhere' in that system the preesure isnt 'free' to release...GOOD LUCK !

[humdingerslammer]

I had a similar thing happen to the front wheels of a brand new Celica. The whole brake booster system was changed and no problem after that... car did 320000 km.

[Roler]

Looking into the proportionate valve, maybe to replace this too.

- Internet gives a valve for the 87-96 Cherokee but gave trouble finding a PV2 proportioning valve for the 97. Are the pre-97 so significantly different that they can't be used on the later years?

-Would an aftermarket PV2 proportioning valve work?

Anyone experience with this?


Have disc front, drum rear. Not looking for conversion to all discs.

[awg]

No experience, but I would be inclined to dismantle, check and refit what you have first, I believe an internal part can become jammed

Have you done any Internet Research ?

I would obtain a valve for your year through private or wrecker network, if one is NLA via Rock Auto

[Roler]

Originally Posted by awg

No experience, but I would be inclined to dismantle, check and refit what you have first, I believe an internal part can become jammed

Have you done any Internet Research ?

I would obtain a valve for your year through private or wrecker network, if one is NLA via Rock Auto

Yes a part can get jammed, even when you bleed the brakes. I forgot the name of it but it's what closes off one part if there is a leak.

Oh Yes I've been on the net for days trying to sort this, even looking into rebuild kits for the proportionate valve. It's not a part that has much info.

Rockauto not giving much for my year.
And what I find online is either 87-96 and then 99-01.