Please be patient this is a long post!!!!

2 weeks ago I towed about 5,000lbs 65 miles with my 98 expy (5.4 RWD 160 miles).

Afterwards it had developed an annoying rear end squeak.

I changed out the U-joints in the driveshaft and most of the noise went away, but there is still a noise at low speeds.

In addition, sometimes when I pull off there is a clunk before you move and if you put it in drive it doesn't move forward until you give it gas.

All of the above led me to think that the rear brakes were dragging. I just took the wheels off now and the drivers side was very hot, but there are a few things I cant explain.

With the wheels off, I got my wife to start the car, put it in drive and ease off the brakes. What's weird is that both sides are squeaking not just the side that was hot. Also I noticed that both rear seals seem to have a slow leak. The fluid level in the diff is about 1/2 inch low and both brake dust shields are oily

I'm going back now to lube up the floating shafts on the brake calipers and back off the parking brake a little, but I'm concerned there is a bigger problem I'm not identifying.

1 - Any comments or advice please!!??
2 - How long are the axle shafts if I decide to pull them to replace the bearings & seals?
3 - I don't have a very big garage, so maybe I'm best off doing this outside or removing the whole axle first???

Quick update

The drivers side disk seems to be warped. I don't have a dial indicator, so I'm going to drop it at O'reilleys.

 

I would be worried about the master cylinder not letting go completely. But that is based on very old experience, not intimate knowledge with a 98'. Used to be, if a line was plugged, or the proportioning valve was messed up, the brakes would stay slightly engaged, like you are describing. Since it seems to be both sides, makes me wonder if the problem is "upstream" from the calipers.

Good luck. Hope others chime in.

Oh -- the clunk makes me worry about the pinion gear and crush sleeve in the rear dif. But "clunks" can occur as well if the shackes are shot on the rear springs, allowing the whole rear end to rotate slightly when you put it in gear, as torque moves to the wheels.

 

OK

Last night I put on new pads and rotors. I also replaced the caliper bolts. Then I backed the parking brake right off.

It was late, so I didnt take it for a long test drive, but the squeak was gone as was the clunk. If you put it in drive it doesn't need gas to get moving.

This morning when I got to work however there was a HORRIBLE burning smell coming from the back and both rear wheels were hot, so clearly I haven't fixed the root problem.

I don't think its the master cylinder because I replaced it only a year ago....... is there another way the brake lines can get blocked? Something must be holding the pressure to those rear calipers.

For what it's worth, it was not difficult to push the slave cylinders back into the caliper when I was replacing the pads.

 

Are you sure its not your parking brake that is dragging? There is a wierd pair of pivots that cause the rear parking brake shoes to expand and contract and they invariably rust up and keep the parking brake from releasing. BTDT!!

 

Thanks PDQFord.

I don't think it's the parking brake because I backed if off the whole way.

I guess I could try remove the parking brake shoes and see if the heat goes away. With the current set up you can push the parking brake to the floor and it doesn't slow the car down at all.

I did some google research and saw recomendations to rebuild the caliper and/or replace the rubber brake lines.

The caliper rebuild kit is like $12, so that might be the next step. I don't see how replacing that rubber line is going to help. I feel like I'm clutching at straws here.

 

The rubber line replacement is to address a problem where the inside of the line can degrade and a flap of rubber comes loose and can act like a check valve and not let the calipers retract.

 

The saga continues.

This weekend I replaced the calipers and brake hoses and bled all 4 brakes. Now I have new rear calipers, hoses, pads and rotors.

So to recap:
Squeak - gone
Brakes binding - gone
Brakes overheating - gone

all to be replaced with a new problem. The pedal now feels very spongy. The stopping power is fine, but the pedal goes all the way to the floor if you push it hard.

I bled the brakes in the following order

passenger rear (right rear)
drivers side rear (left rear)
passenger front (right front)
drivers side front (left front)

I think there is air somewhere in the system.......... but where??? I went through 2 bottles of brake fluid bleeding the brakes.

 

Did you use the pump and hold method or a vacuum pump to bleed the brakes?

 

Moto Mel

I've never used a vacuum pump before. Would it do a better job?

Just to be 100% clear this is the procedure I used:

I ran a clear tube from the caliper into an empty bottle
Wife pushes brake pedal
I open bleed valve thingy
brake fluid and air runs into bottle.
wife holds pedal down
I close bleed valve
wife releases brake pedal
repeat until no more air comes out.


If your answer is that I need to use a vacuum pump, do you have any advice on which one is best?

 

You might be able to get a loaner "Manual Vacuum Pump" from Advance A.P. or AutoZone. If not, they do sell them. "Mity Vac" is the product's name I believe. You could use the vacuum from your engine if you make a trap to catch the fluid and not let it into the engine. My son made a trap using a cheese dip jar and a couple of metal tire valve stems and it has worked great for years for us. The vacuum method works much better than the "pump 'em up and hold 'em" method.