FB/EK Brake Drum measurements

[smclaren]

Hey Guys and Gals

A few questions re brake drums.

- Whats the dimensions of stock brake drums ? Either the diameter of the inner drum lining OR the drum wall measurement. Obviously trying to understand how much material is on new drums.

- Any detail on what the limits of machining are ... ie whats the measurement when they cannot be machined any further ?

- Bonus question. Ribbed/finned brake drums. I was of the understanding that these were standard on utes/vans to help dissipate heat from heavier commercial loads. Is this correct ? Don't know if this was for front or back drums ... or both. Assuming it would be fronts.

I'm looking at a set for sale and would like to know how much life they have left.

Many thanks

Steve

[Harv]

According to the workshop manuals, FB/EK brake drums are 9" ID, +/- 0.005". Maximum allowable rebore is 9.030".

Discussion here on the ribbed drums:
https://forum.fefcholden.club/index.php ... ic=26451.0

Cheers,
Harv

[ardiesse]

Steve,

I think ribbed brake drums were a bit of a lottery. The ex-family EK sedan had ribbed drums both front and rear, but I've seen cars with two ribbed and two plain or even all four plain. Maybe plain drums were more an FB thing. Dunno.

EJ/EH drums are a straight swap for FB/EK drums, and you can get them new.

Rob

[Errol62]

I had a couple of the finned ones I put on the front of my ute. New EJ drums is probably the way to go now days. If not EJ brakes all round.


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[Blacky]

I think I have a set or at least a pair of the ribbed drums - not sure of the size of them and they are in Perth ....

I bought new EH drums for mine but I also converted to EH brakes on the front

[smclaren]

Thanks for the responses, Guys.

Im actually already running finned drums on the front (not the originals) .. but saw another set for sale.

Could have swore that I had tried new EH drums some years back on the stock EK set up ... but seem to remember that they binded once the rims were tighten up. I still have those EH drums so will drag them out and do a full measure up to remind myself what they didnt work.

Thanks again.

[Errol62]

The wider front HD drums will bind, as they need the later rims.


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