Brake Drum Sizes

[mof]

1970 saloon. Last time I bought new brake shoes from a local motor factor I couldn't refit drums without first grinding off about 3mm of meat from the shoes!

Garage insisted that they were the right shoes for the age of Minor.

Time for a new set again.

I have just noticed that 'late' brake drums are 8" and 'early' drums are 7".

I wonder if my drums are a bodge fit by previous owner and are too small for the age of the car.

Does the 8 and 7 inches refer to the diameter of the drum?

Cheers

[aupickup]

YES

[dalebrignall]

go to one of the moggy retailers they will have the right ones

[Orkney]

What Dale said ! save yourself a LOT of hassle

[aupickup]

yes but he does not know the size, so he will have to measure the drum first as it my be possible some one before has fitted the wrong size drum

thats why he asked how to measure them

[mof]

Thanks folks.

Some very speedy replies indeed for a Saturday evening.

Time perhaps for some of us to get out more?!

[Orkney]

Time perhaps for some of us to get out more?

Probably becuase many have been toiling on the mogs all day, come in and theres absolute carp on tv as usual on a saturday night

[Alec]

Hello Mof,

I assume the 3mm is an exaggeration as that is the thickness of the lining material when new. It would be impossible to fit 8" shoes to 7" backplates never mind fitting the drum back on.
Do ensure that the pistons in the cylinders are fully retracted and that the adjusters are wound right off. Also as the linings can slide a certain amount they may need adjusting side ways to centralise them or the drum will not go on.

Alec

[bmcecosse]

As Alec says - this was almost certainly due to stuck cylinders and/or wrongly positioned shoes. Your front brakes are 8" diameter - and nothing should be taken off the linings - except possibly making a v slight chamfer on the leading edge.

[mof]

Thanks Alec, yes perhaps 3mm was a touch of artistic licence, but it certainly was a lot.

Not just a chamfer on the leading edge.

Pistons etc were fully retracted.

It looks like I have eliminated the possibility that I've got the wrong assembly on my Minor and that just leaves me with a cretin at the parts shop I used!

I'll measure up to be sure and then use a reliable specialist mail order site.

Thanks again gents

[bigginger]

It looks like I have eliminated the possibility that I've got the wrong assembly on my Minor and that just leaves me with a cretin at the parts shop I used!

Or, much as I hate to say it, your assembly of the parts. Are you certain the adjusters were at minimum, f'rinstance? I've got that wrong before now
a

[mof]

You are right to be suspicious, but I'm 100% sure about all the settings and slack in the system as I went over and over it all while going quietly nuts!

[bigginger]

Fair enough, but I can't really see the parts being THAT wrong and still going in, tbh