Hot Hubs!

[Americanrider]

My first clue was using 1/8 of a tank to drive accross town. The motor was running fine but no grunt. I pulled into a parking lot and grabbed each hub with my bare hands. The rears where cool but the front ones where very hot all the way down to the locking knobs.
(RED HIGHLITED AREA ON PIC)

I eased it back home and put the ol' girl up on jacks today. I pulled the pass side and the bearings are good, plenty of grease. If anything the lock nuts where a hair on the loose side. I spun them off with a screwdriver, didn't need the 44 hub socket at all.

The next thing I noticed was the backing plate/Caliper mount was a bit loose on all 6 bolts. (see yellow arrows) I could move it about 1/8 of an inch back & forth. So... here is my theory...

If the backing plate shifts then the caliper binds, dragging the brake pad on the rotor and causing heat buildup. Would the brake pad heat travel that far down the hub? Tell what you think? Am I missing another cause? So far I have only pulled the right front. Will do the left side tonight and re-post.

This is on my 67 K20, D-44F from a 1975.

[K5KRAZIE]

The heat from the rotors will dissapate through to the bearings/lockout. Especially if they get hot enough....

[Mudder]

Yep, brakes will get'em real hot.

[special-K]

You hit the nail on the head.I recently had a simular problem on my`Burb.I paid for new brakes(incl.rotors & calipers),I know,I was busy.They didn`t get the spindle nuts tight on one side and that alone was causing drag and heat.I noticed alot of brake dust built up in a short while a few months after the brake job.Usually it`s undetectable.That,and the brakes kept squeeling.I ended up tearing the whole thing down and re-servicing the hole assembly.The rotor got lumpy and the caliper had been cooking,so it was sticking,too.I needed to replace those again,WTF?

[Americanrider]

Late last night I pulled the drivers side. Nothing out of the odinary (bearing wise) but I did find large mounts of brake dust and a bit of shiny shavings all over the caliper mount plate. After a close look at the calipers I noticed the floating sleeves for the mounting bolts had no lube.

Color me stupid, I installed this together back in January in the middle of a cold rain. I figure since the calipers stopped floating back & forth it must have been like driving with the brakes on. It's always the short cuts that come back to bite you. It's a cheap fix and glad I didn't "SMOKE TEST" a bearing set in the middle of a busy road.

[Blazer1970]

That may be it. How old are the brake hoses? Old brake hoses will swell shut on the inside, basically creating a check valve. When you apply the brakes there is a lot of pressure to force the fluid through, but then the hose closes off and holds the pressure on the caliper creating the problem you are seeing. This is a very common problem with old brake hoses.

[special-K]

Don`t feel bad about 1/2-assing it.I did brakes recently on a truck and in a few days they were grinding like I never put pads on,ever.I noticed heavy brake dust,too.I looked into it and I had thrown one pad(caliper side)on backwards.The plunger pressed two pretty little cresents into my brand new pads and the backside did a nice job of grinding grooves into the rotor.Talk about "DOAH!"And I thoght I could do brakes blindfolded.Musta been stress.