brake dragging 5ktq

[Ado Sigal]

To substitute the proportioning valve with known good one or straight 
through block, could be the way to pinpoint the problem.

Cheers,

Ado

>
>On Nov 20, 2006, at 10:17 PM, Doyt W. Echelberger wrote:
>
>  
>
>>Gotta check with the wisdom of the list. My 87 5ktq brakes are not 
>>fully
>>releasing, and at times are dragging significantly....but only on the
>>driver side, and not in a predictable pattern.
>>
>>
>>OK, what are the facts/history:  I've been running the car with the ABS
>>electricals disconnected where they plug in at the ABS controller 
>>under the
>>back seat.  Did that because the sensors were getting confused by the
>>corrosion on the cogs in the hubs, and cleaning the cogs didn't stop 
>>the
>>shudder during the last few yards of a rolling stop. Disconnecting the
>>electricals of the ABS worked fine for about 5 years, and I really 
>>didn't
>>miss it very much.
>>
>>Replaced the MC a few years ago because it was very old and was 
>>causing a
>>creeping increase in pressure as the brake fluid heated up on a long
>>drive.....but that involved both front calipers grabbing, and 
>>replacing the
>>MC corrected the condition.
>>
>>The pads and calipers and rotors and flexible lines are not the 
>>originals
>>and are all only a few years old, as are the hard brake lines. I even
>>replaced all the rusty old brake lines at the rear, when I replaced 
>>the gas
>>tank last year. And the brake fluid is about a year old.
>>
>>If a channel of the MC were causing a problem, I'd expect some drag in 
>>a
>>front and a rear on opposite sides. I've had a bad MC and it acted 
>>different.
>>
>>So, I suspect a problem somewhere in the old ABS unit under the hood in
>>front of the driver.  It is rather mysterious, and I don't know much 
>>about
>>it, and it's electricals are disconnected. But it has the ability to 
>>affect
>>one wheel at a time because I think that is how it worked to perform 
>>its magic.
>>
>>There you have it.  Any lister been there and done that and fixed
>>anything?  I'd like to drive this old workhorse another winter.  I'm
>>considering re-attaching the ABS electricals and letting it chatter a 
>>few
>>times, if it will still  do that.  Maybe chattering will change 
>>something.
>>
>>That's about all I can think to do.
>>
>>Replies appreciated.
>>
>>Doyt Echelberger
>>still alive and living in Ohio and trying to keep an amazing old car 
>>going.
>>
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