Toyota Repair: Brake drag, wheel speed, 22r engine

Question
Hi Ted,

I have a 1987 Toyota 2 wheel drive pick-up.  The most basic pick-up Toyota made, with a 22R engine.  I have a front brake drag problem just identified.  I want to give a little history in case it helps you diagnose the problem.

Around July, I felt a bumpy ride, and pulled over to see if I had a flat tire.  I discovered that I'd left my parking brake on for about 4 miles.  After that, I still occasionally felt/heard a knocking or bumping related to wheel speed.  On one trip to the airport, it was very significant, but cleared up later.  I thought that I'd better check the rear brakes to see if something had broken due to driving with the parking brake on that one time, but both drums/shoes seemed to be in normal condition.  There appeared to be no drag there.  I rotated the tires, and though I didn't inspect the front brakes carefully, nothing seemed amiss there either.  This was ~2 months ago, and I don't remember noticing the problem much after that.  Yesterday, I took the truck out for a drive, after not driving it for a week or so.  When I first moved it, there was some resistance, and a pop feeling or sound when it moved. I looked back in the driveway, half expecting to see that I'd run over something.  Now, I'm sure that the pop was the rotor being moved from stuck pads on it. I drove 5 miles to my friend's, and noticed toward the end (maybe it was present earlier, but I just didn't notice it, but I think that it worsened later in the trip) the same sort of bumping related to wheel speed, along with drag.  The parking brake wasn't at fault. I got out when I arrived, expecting to find a flat tire, but the tires were fine.  I felt the wheels and found one of the front wheels hot and smelling like something burning.  I drove it home today, and it seemed normal today, without the intial movement "pop" either.  I removed the wheel and don't see an obvious problem with the caliper.  The pads are not too worn (they're quite thick still).  The disc is not obviously out of round, or bumpy.  It could be scorched (I don't know how to determine that), but it's smooth and not scored as far as I can tell. The wheel turned freely when I first tried it.  Wanting to see how braking would affect it, I depressed the brake a few times, then tried the wheel again, and found that it had become stuck.  A few minutes later, I put the tire back on, and I was able to turn it with a little effort.  I jacked up the other front wheel to test it; it turned freely.  

So, I don't know why this problem seemed to coincide with my driving with the parking brake on, but the problem is definitely with the right front brake dragging.  As far as my ability/experience, I have a Haynes book that covers my model.  A few years ago, I watched a friend replace my pads and repack my bearings.  I changed the rear linings alone. I don't have a large C-clamp to depress the caliper piston, but I might get one.  My book doesn't give an orderly troubleshooting algorithm for this problem.  By the way, there is no brake fluid leak. I'm not sure whether the problem could be in the master cylinder, brake line, or at the caliper.  What I need is direction on how to approach this problem, what I should do first, then next if that doesn't diagnose/solve the problem.   

Thanks in advance,
Scott

P.S. Since I'm sure that I will ask a follow-up, and it's much easier to reply directly, would you send a copy of your reply to me directly at slaird141@comcast.net?  Thanks.

Answer
This caliper is of the two piece/ sliding pin design, the part of the caliper that contains the piston slides on pins as the pads wear down, these pins may be rusted and sticking, the first thing I would recommend is to disassemble the caliper and check for any rust on the pins, if this is the case you may have difficulty removing them.