Rear "Anti" lock brakes

[original91]

New to the forum. Am original owner of a 91 Eddie Bauer(red).

Kept up, all original.

Have had a problem with the rear brakes locking up with hard braking(especially on the freeway). Brakes are brand new, even had a well established mechanic do it. He said it was the module under the dash(tried to say it was a $500 part) Anyway, I changed the module myself after finding one thru my local parts supplier for $89. I also swapped the sensor, which had a small area that looked like the gears had chaffed it. Still locks up and frankly is scary at times. Albeit, I've driven this thing all 17 yrs so you'd think I'd know, but even the mechanic was guessing(with my wallet no less)

Anyone want to guess as to what is going on?
wpevsner@earthlink.net
Thanks

 

[Potomac30]

Disclaimer: I'm only offering internet based stuff here... not actual experience.

If the rear brakes are locking up when not necessary due to the anti-lock brake feature, maybe you should disable the anti-lock. And if you're the original owner of a 1991 Explorer, then you're old enough to remember how to drive without anti-lock brakes.

Welcome to the forum, there's a lot of good information here and a lot of helpful people. Jump in people and help an old school explorer.

 

[original91]

Thanks Potomac30, I'll give it a try. I just couldn't figure if they are anti lock why it would be the rears.
I already try to drive like I don't have antilocks, but tell that to the guys that slip in the space you create and then realize it when they get too close and jam on their brakes...especially for this old geezer...maybe it's just my reaction time ain't what it was in April 1990 when I bought mine.

 

[burtonbrd138]

are the rear brakes on that year drums? Could be something to do with the internal working of the actual drum itself.

 

[XxxMonoxideChild]

all 1st gens have drum's.

sounds like your rear brake wheel cylinder is not adjusted correctly.

 

[SPORTEXP]

Could the wheel cylinders be leaking fluid on the liners causing them to lock up easily? I too don't think it's in your ABS system. But in the mechanical drums themselves.

 

[pugsy]

When I re-did my rear brakes last fall, I just used cheapy drums and kind of over adjusted the shoes with the star wheel adjuster. Nonetheless, they heated up and warped a bit, so when I would hit the brakes hard, one side would lock up at times due to the warping. I replaced the drums and adjusted the shoes properly and haven't had the lock up issue since.
Maybe you're having a similar problem.

 

[beauboy]

I too have an original 91 (not an Eddie Bauer). You only have rear anti-lock brakes (RABS). Other than the sensors, you have a master control module and a master control valve in the system. I had the same problem as you described. Your symptoms demonstrate that the problem could be in either unit. If your mechanic replaced the module and that didn't fix it, then perhaps you should replace the control valve. After chasing my problem for a number of months with no success, I had the whole system replaced to the tune of about $1000. Considering the age of my Ex, it was well worth it.

 

[original91]

Hey thanks guys(or gals as the case may be):

Unfortunately Beauboy seems to have the most logical answer for the circumstances. The mechanic turned the rear drums with the new pads and I dbl checked the adjustment, and it does appear correct. He replaced the cylinders springs etc.( all but the drums), and I put in a new module and sensor, so unfortunately the control valve(which ain't cheap or easy to do) is probably the culprit. I know then the bleeding process requires some special device to do it properly.

Original91

 

[jackieman402]

Hey thanks guys(or gals as the case may be):

I know then the bleeding process requires some special device to do it properly.

Original91

No, per Ford, that's only for 4-wheel antilock systems (see below for an excerpt from the service manual). You only have rear antilocks so you don't need it. That control valve is fairly expensive though ($175 from Autozone).

http://www.autozone.com/R,2301871/v...partType,01578/shopping/partProductDetail.htm


Here's the shop manual instructions:

REMOVAL & INSTALLATION
1. Disconnect the brake lines from the valve and plug the lines.
2. Disconnect the wiring harness at the valve.
3. Remove the 3 nuts retaining the valve to the frame rail and lift out the valve.
4. Installation is the reverse of removal. Don't overtighten the brake lines. Bleed the brakes.




WARNING
Vehicles with 4-wheel anti-lock brakes require an Anti-lock Brake Adapter (T90P-50-ALA) and Jumper (T93T-50-ALA) in order to bleed the master cylinder and the Hydraulic Control Unit (HCU). Failure to do so will trap air in the HCU unit, eventually causing a spongy pedal. The tools are not required for caliper or wheel cylinder bleeding procedures.

 

[Potomac30]

good post J-man. I noticed on the aZone site that you get $61 back for the old core, so the price is $115. Looks like an easy do-it-yourselfer.

 

[beauboy]

Wow! That's pretty cheap. I wish I'd had this forum when my brakes were acting up. I could've done the work myself and save a ton of money. Best of luck.