01 ABS prop valve cause non-ABS disk to drag?

Hey gang, swapped out the ABS D35 in an 01 XJ (4.0L, auto) for a Tera60R with disks...and it seems that there's a bit more than 'normal' drag on the rear calipers. Enough to the point that one of the calipers has started to change color, though it has only been driven LITERALLY 2 miles. Up in the air you can spin the wheels, which turn relatively freely, but they stop just a little bit sooner than expected. I can't help but think that the proportioning valve is keeping just a little more resistance in the back for some reason. Brakes have been bled and Tera thinks the same thing we do.

Anyone know without speculating? I've got plenty of speculation on hand, but am out of stock on hard evidence.

Thanks in advance.

Still trying to work this through.

I'll take ideas now.

all i can say is buy and adjustable prop valve or attempt the tried and true ZJ prop valve...


another idea:
when the rear ABS tone ring lines were disconected, are they shorting? maybe causing the ABS system to apply the brakes?

another idea:
Have you pulled the ABS fuse so that the system at the master and booster stops working?

when i swaped from the ABS d35 to the non-abs ford 9" i have had no issues, but i went from drums to drums... maybe calipers are different?

XJ_ranger said:

all i can say is buy and adjustable prop valve or attempt the tried and true ZJ prop valve...


another idea:
when the rear ABS tone ring lines were disconected, are they shorting? maybe causing the ABS system to apply the brakes?

Click to expand...

One thing we're thinking...

another idea:
Have you pulled the ABS fuse so that the system at the master and booster stops working?

Click to expand...

Yes, still dragging...which makes us think that the prop valve is the cause.

when i swaped from the ABS d35 to the non-abs ford 9" i have had no issues, but i went from drums to drums... maybe calipers are different?

Click to expand...

Well, where we're stuck is that in our experience switching to calipers makes for a squishy pedal...requiring more proportioning to the rear. Pedal is nice and solid, brakes are properly bled, etc. Stops just fine, just draggin' a bit.

I did a disc swap onto a 8.25 to take the place of my D35 with drums....the way I understood the situation was that drums require a lot more brake fluid than discs do, I swapped in a ZJ proportioning valve from a ZJ with 4 wheel discs at the same time as my disc swap (didn't feel like bleeding twice so I have no experience with the XJ prop valve on discs) but I can tell you that my brakes work really well now and don't drag....I got mine for $8 plus $6 ship on ebay...keep your eyes open for one.

Got the issue fixed today. Teraflex sent out new backing plates because we noticed that the pads were wearing on the top of one, bottom of the other. New backing plates fixed the problem. Both backing plates were bad. Tera took care of us though.

Thanks for the help.