KKRRSS

A few months ago I found a black boot under the front of my truck (see image, object at the bottom). I removed the caliper pin and replaced the boot, thought it was a one-time fluke. The boot is oriented with the large flange facing 'inward' towards the engine. There doesn't appear to be much that keeps this boot in place. None of the other boots (3 others) are even loose. Now today, I go out to bleed the brakes and this boot was hanging on my 1mm.

Why is this thing coming loose? Should the flange be facing outward so that it can't slide through the hole in the caliper? I wonder if these were all installed incorrectly at the last brake job? The Haynes manual isn't detailed enough to show this/explain this.

Also, I looked at the rear drums and there is no way I can get a bleed wrench on there and turn it.... what gives with this? How to bleed the rear drums when there doesn't appear to be any room to do it.

Last question: I want to bleed the brakes because my left rear wheel has begun locking up for no reason at all. It's intermittent and very unsettling.

KRS

torquefan

At some point, someone has installed rebuilt calipers on your truck. During rebuilding, they will hone out the slide bores that your rubber bushings sit in, to remove rust. I have seen many rebuilt calipers where that bore has become too large to hold enough tension on that bushing. If you have already tried a new bushing and it still pops out, it's time for another set of calipers.

Regarding the rears, it is definitely tight in there, and there won't be enough room for one of those 90 degree bleeder wrenches, but a decent 6 point box-end wrench will do the job, provided your bleeder screws aren't seized in there. At this age, you may want to start out with new wheel cylinders. If you have one wheel locking up, I would first inspect the rear brakes for contamination from a leaking axle seal. Bleeding won't usually correct that issue.

Robert Rausch

If your rear brake is locking up you should ask yourself if you've been backing up a lot lately, especially going backwards down a long hill. If the answer is yes, you've probably just automatically tightened the brake adjustment star-wheel too much. Just back it off with a screwdriver and with the wheel off the ground.

KKRRSS

Do I pull the wheel to do this?

nickg

I second the fluid leaking on the shoes causing lock up, usually gear oil or a leaky wheel cyl, best to pop the drum off for a looky see. bleeding it wont cure it, even if it as air in the system it could not, would not, cause a wheel lock up.

I dont buy into the self adjuster tightening too much, there would be other issues at play if you have a lock up issue because of this, the adjustment mech can only apply so much force to the star wheel, purely just by the way its designed.


sorry Robert
20+ yrs as a mechanic, never saw that happen, and its never taught that it could happen, more than likely if you have something like that happening, and you do back it off and it seems to cure the issue, something is wrong and your just masking it, by backing it off

KKRRSS

Will pull drum in the morning... never had these off so I'm in uncharted territory here. Done lots of disc brakes, never a drum.

KKRRSS

Robert Rausch

Well, it happened to me nickg! I had a buddy who had a steep driveway with no place to turn around at the top. I'd drive up and then back down in reverse, hitting the brakes pretty regularly in order keep my reverse speed down. After maybe 7-8 times doing this, one day I noticed the truck was pulling just a little, and left rear brakes smelled hot. After a few more times backing down that steep drive, the left rear brakes really tightened up, and began to lock up on gravel. That got my attention, and I jacked the truck up, crawled under with a screwdriver and loosened the star wheel. Everything returned to absolute normal--no pulling while braking, no hot brake smell. I had no leaks--it was obviously the backing down that steep driveway, and applying the brakes that tightened them up.

KKRRSS, if that is your problem, you'll only have to jack the wheel/tire off the ground and adjust the star wheel as it says in the Service Manual. It's not hard.

blackimpala

If you have trouble getting the drums off try this, with the rear on jack stands
Wheels off a couple of lug nuts on part way, start the engine put it in gear let the rear drums spin, slam on the brakes. The drums should be loose if not you may need to back off the adjuster until the rige on the drum will get over the shoes.

Floyd

Robert Rausch

Ditto what Floyd says. Just be sure you put a couple of lug nuts back on before you spin the drums or they will come off and bang around the inside of your shop. Don't ask me how I know this!

KKRRSS

Drum and shoes were normal, a little worn but nothing out of the ordinary.

Napa was closed

Checker didn't have the drums

So, I buttoned it back up. That was a miserable 1.5 hours worth of work.

I'm not sure that I'll ever, ever, ever work on my truck again.

Where is there a good shop (or home mechanic) that knows these 3/4 ton diesel trucks? Anyone?

KRS

KKRRSS

New rotors, new pads on the front; new left front caliper (sheared off the bleed screw), speed bleeders all around, 2 qts flushed through.

Brakes still a little spongy; wondering if I have a rubber line going bad, going to check it out this weekend.

KRS