williamarthurascs

I recently purchased a 62 on a 58 frame (MUTT) and completed a brake overhaul. All shoes, drums, cylinders, hardware, fluid, rear brake hose and steel lines, and rear axle shaft bearings. I have adjusted the shoes multiple times but the left rear get's smoking hot after driving about 5-10 miles. I removed the linkages inside the drum for the emergency brake thinking maybe a cause of dragging but no change. Can someone give me a clue as to what might be causing a single wheel to overheat after all of this maintenance? I am down to condeming the rear differential gear cluster causing the axle to overheat?

davekp78

Did you add self adjusters? If so, the left might be backwards.

Frankie the Fink

It is most likely, "...all this maintenance". To field strip it; heat is the result of friction, which is produced by two surfaces rubbing against each other - in this case the drum and shoes. The only individual parts in that instance are:

1) the rubber brake hose,
2) the small metal line that connects the rubber line to the main hard line
3) the wheel cylinder, and,
4) the various springs, nail pins, etc...

Your first move should be to take the OTHER rear wheel off and closely compare the components and assembly. Post pictures if you like. Make sure you have the leading and trailing shoes properly oriented, and, you did lube the 6 "slide points' on the backing plate lightly ? Right ?

williamarthurascs

Wheel assembly with parking brake removed for testing

Thanks for the inputs
No self adjusters are installed
New rubber brake hose from the main brake line running down the frame that connects to the NEW brass connector and NEW steel brake lines running across the diff housing
New wheel cylinders l and R
New hardware, springs, retainers, clips etc
Primary shoe (shorter pad) forward
Backing plate slide points dressed down smooth with light angle grinding and lube
No difference, axle and drum get smoking hot (enough to burn your flesh) after only driving a short distance and only 10 routine brake applications.
What next?

dplotkin

Any evidence of dragging on the other wheels, just not as much? Rear brake hose known to be good? Anyone replace a master cylinder or fool around with the pushrod adjustment, if any? Is there for whatever reason a residual valve in the line somewhere?

Dan

Bill Pilon

Sounds like a defective wheel cylinder, or shoes need to be arc ground. I never replace brake shoes without truing up the drums and arc grind the shoes to mach the drum.

Always have great brakes from day one.

Bill

williamarthurascs

no residual valve, and no tampering with master cylinder (common to all four wheels), no evidence of brake drag anywhere except left rear. New wheel cylinder (replaced 2X) and new drums, and new rear brake hose and metal line as stated ealier. Disassembled 3:08 rear and found axle gear shim on left axle warped and gaulled with center worn oversize. Suspect axle was overheating due to defective gear shim and heat transfering out to wheel assembly causing brake overheating condition. Jury is still out on this fix.

steampunk c1

Axle bearing maybe

williamarthurascs

As previously stated BOTH L and R axle bearings have been replaced with NEW bearings and no fix for overheating

Frankie the Fink

Hmmm....let us know if that was it.

HilltopClassicCars

If you have an IR temp gun, I'd take readings immediately after a test drive to determine the hottest items. If the axle in the area of the bearing is hotter than the brake drum, your issue is probably related to the bearing. If instead the brake drum is the hottest item, then it probably is related to the brakes.

I'd try backing off the adjuster on that side to the point just beyond having no drag of the shoes against the drum and take it for another ride, perhaps the shoes are just adjusted out a bit too far?

dplotkin

I follow you but I would think any bearing failure that would allow the brake assembly to conduct that much heat would seize itself.

But I agree that brakes adjusted too tight will get them hot, the servo effect of the shoes will make them hotter and the hot fluid will expand and push them against the drums more...and so on. At that point he would smell them, not just feel them.

Dan

HilltopClassicCars

I don't think it's a bearing issue but ruling it out is painless with an IR temp gun. He did say the drum gets "smoking hot" and "no evidence of brake drag anywhere except left rear" so the left rear is clearly dragging, the question becomes is the dragging a cause or symptom of the problem?

If they are getting smoking hot, I'd think there would be a fragrance as well.

Frankie the Fink

That's why I'm keeping mum until the jury is finally in....

williamarthurascs

oh there is plenty of odor as well as excessive heat! (sorry I did not mention that) still waiting on the rebuild and install of the differential to see if the issue gets resolved by way of the side gear shim issue

williamarthurascs

Well the 308 is out, the 411 is in and the left rear brake assembly still overheats? I am at my wits end with this POS. Next step, capping off the rear brake line at the rubber hose and running front brakes only to see if the LR heats up without fluid pressure going to the wheel cylinder. Possible partial blockage in the steel line connecting the front T to the rear T? But why would the left rear brake drag and not the RR when they both operate using the same steel line? A real riddle, wrapped in a puzzle within an enigma.

Frankie the Fink

All right - I'm back to post #3...

williamarthurascs

All the points that you made, and suggestions in post 3 were completed LONG before post 16. The problem still exists!! Most difficult brake issue I have encountered in 45 years as an ASE certified mechanic.

Frankie the Fink

Well MikeM always suggest taking the drum partially off and having somebody operate the brakes so you can actually see what happens... A sticking wheel cylinder, collapsing brake rubber hose or binding somewhere may just show itself this way. Just because parts are new don't mean they're good...

After your helper lets off the brakes you should be able to rotate the drum(s)...

williamarthurascs

Been there, done that, drums rotate freely. Star adjuster backed completely off (max shoe to drum clearance) drum will actually slide off easily when wheel gets removed (brake pedal position suffers LOW). In this condition, after a short drive, the drum is hot enough to fry an egg on?