brake dragging 5ktq

[Doyt W. Echelberger]

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.

I don't drive the car every day, and with this brake drag problem I drive 
it even less. Maybe I drive it one week and then not the next at all, or 
let it sit two weeks at a time.

Last week I drove the car 4 miles, going about 55mph for the first two 
miles.  I could feel a brake drag when I pulled out of the driveway.  On 
the highway for about two seconds the drag slowed the car down a little bit 
and then seemed to let up, so I kept going.

At the two mile mark I stopped and walked around the car, looking at the 
rotors and feeling the wheels for heat.  The driver-rear rotor was glowing 
a medium red and the wheel was hot...too hot to touch. I figured it was 
cooking the grease out of the hub and it scared me a little. Never saw it 
glow red that way before. Pretty alarming.  The other wheels were normal.

I turned the car around and drove it back home at a _greatly_ reduced 
speed, maybe 25-30 mph, and parked it, thankful that the trip didn't 
require a flat bed. Then I went inside and let it cool off for a few days 
while I thought about it.

OK, so it cooled off. Wonder if it will do that again? Did the same 2 mile 
drive, and there was some brake drag, but when I stopped and did the same 
walk-around, all the wheels felt normal except the driver-front, which was 
warmer than my hand but not hot enough to make me pull my hand 
away....maybe 140 degrees F ? That rear rotor was normal.  Now the front 
driver caliper was acting up.

Big mystery. Gotta take the system apart and look at everything first. 
Drove to shop, let everything cool for a day, put car on a lift and pulled 
all 4 wheels and checked calipers and tested the pins that usually hang up, 
and checked both rear emergency brake cables and levers.  Up on the lift 
everything working and loose like it should be.

Put the wheels on and drove it on the streets again and the brakes started 
dragging again, so I parked it and sat down to write the list.

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.