Brake drums/drive flange

Technical MGB discussion
Post Reply
Rattie
Posts: 2
Joined: Mon Jun 08, 2020 10:30 am
Forename: Vic
Surname: Todman

Brake drums/drive flange

Post by Rattie » Tue Jun 09, 2020 12:46 am

Decided that replacing my 52 year old brake drums, would be a good lock down project. When I separated the drum from the flange, both the mating surfaces were thick with rust. Were they originally painted? Would it be a good idea to do so now?
Thanks
Vic

Ian Fozzard
Posts: 391
Joined: Fri Mar 27, 2015 8:18 am
Forename: Ian
Surname: Fozzard

Re: Brake drums/drive flange

Post by Ian Fozzard » Tue Jun 09, 2020 8:23 am

I don't believe these surfaces were painted at the factory. The drum is (I think) cast iron, which doesn't rust as readily as mild steel. I would clean everything up with a wire brush on a drill or angle grinder (eye protection essential!) and see how things look. The original drums are good quality material, and unless excessively worn or corroded on the braking surface, or cracked, should be perfectly serviceable. When cleaned and checked a wipe over with light oil on the mating surfaces and some heat resistant paint on the outside (cosmetic!) should finish the job. Make sure the braking surface is perfectly clean and the shoes are clean and not excessively worn.

Ian F
1972 BGT, Blaze, Navy trim, recessed grill
1961 Midget, 948cc, Clipper Blue, Blue trim and weather gear

User avatar
George Wilder
Posts: 221
Joined: Mon Sep 22, 2014 5:43 pm
Forename: George
Surname: Wilder
Location: North West Essex

Re: Brake drums/drive flange

Post by George Wilder » Tue Jun 09, 2020 8:55 am

A liitle known fact the connection between lawnmowers and MGBs.

Certainly on early cars like my 65 with original brake drums when cleaned one willfind a Qualcast sysmbol - yes the same iron founders who made lawnmowers! They made lots of cast ironbits for industry.
George Wilder
1965 MG MGB Mk1
1995 MG RV8
2005 MG TF 135
1959 BSA D7 Bantam

User avatar
Michael Barclay
Posts: 57
Joined: Tue Dec 06, 2016 8:05 pm
Forename: Michael
Surname: Barclay
Location: Abingdon

Re: Brake drums/drive flange

Post by Michael Barclay » Tue Jun 09, 2020 9:47 am

Hi George
Looked at my drums. They were still making them for MG in 1974 . I use a VERY thin smear of copper grease on the the hub mating surface before fitting the drum. Obviously be very careful as grease and brake shoes dont mix!
This prevents them from rusting and sticking when trying to remove at a future date.
Best regards
Mike Barclay

User avatar
Peter Cresswell
Posts: 613
Joined: Fri Oct 31, 2014 10:05 am
Forename: Pete
Surname: Cresswell
Location: Stone, Staffordshire

Re: Brake drums/drive flange

Post by Peter Cresswell » Tue Jun 09, 2020 11:48 am

I always refit the drums to the hub in a spotlessly clean (wire brush + lots of brake cleaner) and dry. I've never had a problem with removal and when refitting the drum there is nothing to prevent it running true. This is most important as if it runs out of true by even a couple of thou the brake judder will be unbelievable!
Pete
1969 MGB Roadster
2011 MG 6 TSE Magnette
2007 Mercedes SLK
Plus 32 other cars since 1965

Rattie
Posts: 2
Joined: Mon Jun 08, 2020 10:30 am
Forename: Vic
Surname: Todman

Re: Brake drums/drive flange

Post by Rattie » Thu Jun 11, 2020 12:33 am

Thanks for the advice - The old drums were badly scored by the rivets that secured the linings to the shoes in the old days.
New shoes were fitted sometime before 2010, but a leaky oil seal made them useless.
Vic

Post Reply