Stumped by drum brake/hub assembly

Stumped by drum brake/hub assembly

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ChemicalChaos

Original Poster:

10,397 posts

161 months

Friday 27th February 2015
quotequote all
Afternoon all,

As part of my weekend work I'm trying to disassemble a drum braked axle to rebuild the cylinders with new seals. I am trying to remove the backplate complete with cylinders and shoes still attached letter, to work on the lot of it together on the bench.
Based on my experience with Land Rover axles, once the brake line has been disconnected from the cylinders, the backplate simply unbolts from the axle tube and slides off over the hub bearings.
This axle is from a 40s/50s US light truck, possibly GM, but I don't know which. The backplate is held onto the axle with 6 bolts, 4 of which I removed, 2 of which the nuts had rusted to nothing (probably from fluid dripping on them) so I drilled and chiseled the heads off. The holes the bolts pass through are not threaded.
By my logic, the backplate should now come off, but it will not budge. What is confusing matters is the very unusual pinch-bolt wheel bearing/oil seal arrangement inside where the drum would be - I cannot tell if:
A) this must be removed first to get the backplate off
B) the casting and backplate are in fact one assembly
C) the backplate is simply rusted to the axle tube and just needs an even bigger hammer to persuade it.

I'm fervently hoping the answer is C, but can anyone with experience of this arrangement please shed some light?

Thanks,
Matt

Hub assembly:



Closeup of weird seal casting:



Join of backplate and casting - one piece or just rusted on?



View behind backplate:


ChemicalChaos

Original Poster:

10,397 posts

161 months

Friday 27th February 2015
quotequote all
Thanks chaps.
I didn't want to remove the plate, but the fixings for the cylinder, and pipe unions on it, are one big lump of corroded mess. As you can see, there isn't the light to see or the space to get my head or any big tools in behind it - any undoing of nuts has been by feel.. which is fine if the nuts are still not shaped and not siezed frown

Even if it would not come off, I can still pull it forwards and spin it round to get proper access to the fittings

ChemicalChaos

Original Poster:

10,397 posts

161 months

Saturday 28th February 2015
quotequote all
Hi all, thanks for the replies and advice.
Today I doused the joint in penetrating fluid and applied the Engineers Persuasion Tool No.1
Result! The backplate soon sprang free from the axle, and even better it just about fitted over the pinch casting too! Turns out the pinch casting is actually part of the axle tube rather than a separate part attached to the flange.

Here's the axle all cleaned up:



And to answer an earlier question, here's one of the top two bolts that was refusing to undo and had to be drilled. Turns out it wasn't an anti tamper job, just corroded to nothing! I can only guess that brake fluid has leaked onto it over the years