Rear brakes. Brke shoe pivot point

[John Mason]

Hello all,   I have a 1935 Mk1 Ruby.  On examining the rear brakes I found that the bottom pin (one nearest the ground)in which the brake shoes go in is quite loose in the back plate. So loose that when the brake drum is off  it can be moved in and out of its mounting hole with the slightest of finger pressure although there is no sideways or up or down movement.  There is no fixing to hold it in place.  I don’t think it should be loose on the mounting hole. Well at least not to the extent it is.  Can anyone confirm how tight this brake shoe pin should be.

John Mason

[bystander]

The brake shoe pivot pins, front and rear, should be tight. If they are loose there will most likely be brake judder or snatch. The rear pivot pins on a '35 have a plain shank and should be peened over tight when fitted. Very common for them to work loose as you describe, either punch them back up tight, or if that fails, perhaps a touch of braze on the back. Another possible solution is to replace them with the very early type front pivot which is the same shank diameter but longer and threaded to take a nut. This type may be available from the cherished suppliers, but specify the very early type, not the later one with a much bigger thread diameter.

[Bob Culver]

If you have any mates with a lathe it is a simple task to make, including oversize to maintain the force fit, and threaded if desired. The bore can be sorted with a reamer or perhaps a drill aplied carefully. Material is the problem. Have to be tough. A HT bolt may nor suffice. The softer versions of old back axles suitable. Readily available! Replaced on my car eons ago with ones made from Model T axle.

[Parazine]

These brake shoe pivots are a pain, either coming loose or snapping completely, like the one on the right of the photo. 


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A friend had a rear one snap on the road and found it impossible to change without splitting and removing a rear hub, not a job he wanted to undertake in a layby on the A303! Since then, he has made a number of the item on the left, a pivot pin, drilled and tapped with a suitable HT bolt. This can be fitted without dismantling the hub so I have one in my emergency spares tin under the seat of each car.

[Bob Culver]

That is a neat remedy. Assuming there is room for the bolt head. A good tension reduces chance of fatigue fracture as the photo. Use of a HT bolt solves the materila problem. need not be (cannot) be an interference fit. There is just the dilemna of which thread.... Considering that near all the braking can concentrate on the stop, maybe 1/2 ton, do seem modest.

[John Mason]

Thank you for the replies and ways of effecting a repair.
This brings up another couple of questions.
1. Can the brake pivot be removed without removal of the hub first.
2. If the rear hub has to be removed what disturbance if any is there to the half shaft. Is the castle nut on the end of the shaft the one that has to be checked for tightness again and again with a long bar.

John Mason

[Howard Wright]

Hi John

If you use Parazine’s excellent repair idea and you can get the old pivot out then you might not have to remove the hub.

Otherwise that half shaft nut will have to come off and on reassembly be tightened up to within an inch of its life and a few miles later tightened again.

Cheers

Howard

[Hedd_Jones]

Having had to deal with one in situ, where the end flange had came off, I can confirm they can be removed.

I lopped most of it off with a slitting disk in a 9 inch grinder, then with a grinding disk ground it flush to the axle casting.

I ground the dome on the inside face of the casting smooth also, centred, drilled to a smidge over 1/4 and fitted pretty much what parazine has pictured.

I believe I made the pivot out of an old bolt, and used a 1/4 HT bolt to fix, thinking about it, might have been a nasty metric (but 10.9) button head.

I plastered the thread of the bolt where it engaged with loctite (to stop it coming undone) and the bit in the plain hole with 'poxy metal  (to take up all the clearance as the original is basically a rivet).

Once it all went off I dressed the head a bit with a file, and with a couple of coats of some gloopy black paint no one need ever know I did it.

That was probably 15years ago. No problems since.

[John Mason]

Thank you all. Yes I am going to steal Parazine’a excellent idea ( Hope he doesn’t want royalties.)and Hedd mine will also be no doubt metric thread.

John Mason

[Parazine]

You're welcome!