Brake shoes

[k. rogers]

Stupid, I know, but thought I would fit my new brake shoes which I've had on the shelf for about 12 months to the front of the Weasel before the National so I've got time to bed them in. Problem is, they're too tight even with the adjustment nuts relaxed right off! Anybody else had a similar experience? When I compared them to the ones I took off the car they were a good 1/8 inch greater radius. I will bring them with me at the weekend in the hope someone from JCS can take them back to club spares (I was too late to phone them tonight!)

[ian Howell]

There were/are two thicknesses of lining, 1/8" and 3/16", the thicker ones being on later (post 1932?) cars.

There was a post here some time ago explaining that stocks of the 1/8" linings were exhausted and the club was investing in tools to have shoes cast that would take the thicker linings.

I don't know if it practical to machine 1/16" off the 'old' type shoes or possibly skim the drums by 1/8" (diameter).

The drums on my car have been machined (NOT BY ME!) to +1/16" + 0.020" according to a chalked message I found when I rebuilt the brakes.

George Garside may be able to shed further enlightenment!

[george garside]

The only thought I have is that Jowetts recommended that drums be replaced when diameter has been increased by more than 1/8th inch.
on that basis if drums are not worn ( original size 10.003 - 9.997") it would be ok to have them machined out to around 10.003" plus 1/8th plus maybe a few thou extra!

I am suggesting this on the basis that the factory recommendation for when to replace drums would have been made on the assumption that annual mileage couldhaave been anything from five to fifty thousand miles a year so the drum would haave worn beyond acceptable limits. This is unlikely to occur now when many 'classic' vehicles do less than 1000 miles a year.

One can also assume that the factory limit was playing on the safe side and that going a bit over it was unlikely to do any harm??

george

[ian Howell]

So:-

Thanks for that George, that sort of coincides with my thinking.

However, does this also mean that if the drums are a bit worn/grooved, then having them machined to 1/8" oversize would restore them to a working condition AND allow the use of the thicker linings on the existing shoes, thereby eliminating the need to make special "undersized" shoes?

Discuss . . .

[george garside]

That's the way my mind is working! But with the caveat that such arrangement would only allow for a limited mileage before the drums became useless.

But that may not be a problem for many as 10,000 miles may represent 10 years of gentle use as opposed to the ,say, 6 to 9 months when using as the makers intended!

The 'purists' and those with a bottomless purse may differ!

george

[richard turner]

I have discovered some detail in a 1937 Raybestos brake lining catalogue. It lists thicker linings from 1937 models with a corresponding reduction in the shoe thickness. The drum diameter remains at 10 ". I will try to scan the relevant pages and post at some point. Rich

[george garside]

from the September 1936 i.e. 1937 models the brakes are completely different to those on the 7hp vehicles so the shoes are not the same. However 1937 model year commercials had 8hp engine but 7 hp chassis and running gear following Jowetts normal practice of using up parts for the following years commercials. The Bendix brakes came in on the 1938 commercials

george

[Tony Fearn]

I have discovered some detail in a 1937 Raybestos brake lining catalogue. It lists thicker linings from 1937 models with a corresponding reduction in the shoe thickness. The drum diameter remains at 10 ". I will try to scan the relevant pages and post at some point. Rich

Hello Richard.
I'm sorting through my pre-war brake shoes and brake drums at the moment, and wonder if you could post the relevant Raybestos information you mentioned in 2015.
Thanks,
Tony.