Brake shoes on Ebay

[ian Howell]

I JUST missed the end time for these items and I need a couple of shoes for my 1930 Long Four.

Could the advertiser PLEASE respond to my message on the eBay site?

I will happily make any 'spares' available for other needy parties!

CONTACT NOW ESTABLISHED, BU THE PLOT THICKENS (OR THINS!).

[Tony Fearn]

Don't panic Mr Mainwaring!!
Send me an email if you don't get a response from the eBay guy.

brake shoes.JPG

Regards,
Tony.

[ian Howell]

Tony: -

Many thanks! I am in touch with Richard T from Colwyn Bay (Current member JCC?) and in shedding light he has compounded my darkness!

He has shoes to accept different thicknesses of linings, but I (mis)understood from recent commets by Ian Priestley that the thinner linings were no longer available and that the club was tooling up to produce shoes that would take a thicker lining that was available (I assumed from another make, F---, or Au----, etc! If there were shoes available that took thicker linings, why bother?

Now it seems that at least two types of shoe were used - presumably at different dates - but how does one know which is which? Different casting numbers? Different base thickness? Other?

There is no reference to this matter in the notes that Bob Jones produced all those years ago and which I find generally invaluable. I am adding my own snippets as I find them (yours too - like "How to set up mechanical brakes").

Anybody else care to join in the fun?!

[george garside]

??if there are two thicknesses of shoes in circulation then why is JCS producing new ones to take thicker linings???. I personaly cannot recollect 2 thickneses of shoe but don't take that as definitive.

As far as I am aware all 7hp four wheel brake drums were the same diameter i.e. from '29 to '36 on cars and '37 on commercials.

george

[Jack]

He has shoes to accept different thicknesses of linings, but I (mis)understood from recent commets by Ian Priestley that the thinner linings were no longer available and that the club was tooling up to produce shoes that would take a thicker lining that was available (I assumed from another make, F---, or Au----, etc! If there were shoes available that took thicker linings, why bother?

Now it seems that at least two types of shoe were used - presumably at different dates - but how does one know which is which? Different casting numbers? Different base thickness? Other?

Anybody else care to join in the fun?!

Well, not sure if this necessarily qualifies as fun but I did mention these to Michael KO as possible spares for exchange at JCS. He advised that prewar shoes came in two very slightly different sizes, one of which you can no longer get lining material for.

As a result of this, since there may well be members who have the "wrong" size who need new liners, JCS are having the "right" shoes made up as these are not widely available and they evidently did not have stock of the right size to get relined.

Since we don't know whether the shoes in the ebay listing are the right or wrong ones, they might be a brilliant boost to available stock or they might be useless with no way of knowing other than someone who knows the difference looking at them. I would have thought Ian Priestley or Michael could advise, might be worth a call to see if there is any way of a layperson knowing or checking. I suppose at a cheap enough price it is worth the gamble perhaps.

Jack.

[Jack]

Okey dokey. Worth clarifying for the records, huge thanks to Michael K-O who has gone out of his way to clarify and ensure accurate information with his colleagues at JCS.

He writes:

"Brake drums are all the same size but the shoes for models 1929-1935 inclusive are larger and take 1/8" thick linings. For 1936 onwards models the shoes are slightly smaller and take 3/16" thick linings. There is no way in telling the shoes apart even if you happen to have one of each size and you put them side by side you cannot tell. That is why we have had to have new lined shoes made to be certain that they are compatible. Only if you KNOW your car is on the later/smaller shoes that will take the thicker lining are you safe. If you have the earlier/larger shoes and you have them lined with the thicker material you either cannot fit them because they will be too tight or if you can fit them (due to excessive drum wear) they will not operate properly. Apart from buying the correct items from JCS for 1929-35, later shoes (if you know they are definitely small) could be obtained and just lined with the thicker material. However, as this is a critical safety issue we cannot be advising members to mix and match, we can only advise them to buy the bona fide item from JCS."

Good advice, and clearly by "smaller" we mean very marginally smaller diameter once fitted, and this seems to be very difficult to spot even if you know what you are looking for. Worth contacting JCS for new shoes if you need to replace rather than taking a chance with something so important which can so easily be incorrect.

Jack.

[ian Howell]

Well then!

Many thanks to Mike K-O for the extra information.

I suppose the difference is that of 1/16" shared between two shoes, Just on 33 thou' so no wonder it is difficult/impossible to tell the difference!

A bit like boy and girl jelly babies - no much difference, just a bit more jelly!

[george garside]

I am not an engineer so this may be a daft/impossible thought - would it be possible to mount a pair of brakeshoes on ? a faceplate to skim 33 thou or whatever off them or something like that

george

[Jack]

I am not an engineer so this may be a daft/impossible thought - would it be possible to mount a pair of brakeshoes on ? a faceplate to skim 33 thou or whatever off them or something like that

george

I would expect the JCS remanufactured shoes are cheap enough that modifying larger ones is probably not economical and potentially thinner shoes might not be a great idea (but it doesn't sound like a big difference) unless you strengthen the inside, but anything is possible given enough time and resources and if we didn't have the luxury of JCS remaking this type of part it certainly would be worth considering.

Jack.

[Tony Fearn]

A recent offer on eBay UK was a job lot of 11 pre-war brake shoes. Apparently there were TWO TYPES of brake shoes fited in the pre-war period, early ones taking 1/8" linings and later ones 3/16" linings. I am told by the leading authority here that it is impossible to tell which is which - even if you have them both in your hand as to be unidentifiable.

Is it possible that all the brake shoes were all the same, and the internal diameter of the brake drums were different?? ......Discuss.

Tony.

[ian Howell]

Tony: -

You may have found an answer. The drums on my car have a chalked message inside: - 10 1/16" + 0.020"

1/16" seems excessive for a first skim so I suppose this might mean either 10 1/16" drums bored out +0.020" to correct unveven wear or possibly 10" drums bored out 1/32" TWICE and then a further 0.020".

If this might be the case, has anyone got some drums from a late 30's car (ie one with 3/16" linings) that could be measured? It seems unlikely that very many would have been bored out 1/6" so if 10 1/16" is a common size then your idea could be right.

[ian Howell]

(Copied from 1930's Jowetts in NZ section).

Well, back home now and my original theory appears not to hold up. To recap: -

Early (How early?) brakes had a tendency to squeal. This may have become more evident when front wheel brakes were introduced in 1930 (29?). A set of drums that I acquired from Alan Benewith's collection had HUGE hose clips around the outside, I assume to reduce/eliminate squealing.

When Jowetts changed to thicker linings in 1935/36? surely it would have been simpler/cheaper to bore out the drums a little larger (possibly new foundry moulds needed, but not too expensive). Might this also have raised the resonant frequency of the drums and thereby reduced the squealing problem?

They appear to have chosen to have smaller brake shoes produced. As these are die cast aluminium, the tooling costs must have been significant. Perhaps this approach taken because the 'new' shoes had to fit, and work on, earlier car's brakes. Does anyone know if this also cured the squealing?

The only way the 1/16" thicker linings could be accomodated would be by reducing the 'height' of the curved lining support surface above the datum of the operating 'cam' (flat plate) and the shoe pivot.

So, given suitable supports at each of the datum points it should be possible to distinguish between the two shoe thicknesses. Shouldn't it?

Discuss.