Brake drums/drive flange

Technical MGB discussion
Post Reply
Rattie
Posts: 3
Joined: Mon Jun 08, 2020 10:30 am
Forename: Vic
Surname: Todman
MGCC Member: Yes
MGOC Member: Yes

Brake drums/drive flange

Post by Rattie »

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 F
Posts: 920
Joined: Fri Mar 27, 2015 8:18 am
Forename: Ian
Surname: F
MGCC Member: Yes

Re: Brake drums/drive flange

Post by Ian F »

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
MGCC member
1972 BGT, Blaze, Navy trim, recessed grill
1961 Midget, 948cc, Clipper Blue, Blue trim and weather gear
User avatar
George Wilder
Posts: 240
Joined: Mon Sep 22, 2014 5:43 pm
Forename: George
Surname: Wilder
MGCC Member: Yes
Location: North West Essex

Re: Brake drums/drive flange

Post by George Wilder »

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: 133
Joined: Tue Dec 06, 2016 8:05 pm
Forename: Michael
Surname: Barclay
MGCC Member: Yes
Location: Abingdon

Re: Brake drums/drive flange

Post by Michael Barclay »

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: 759
Joined: Fri Oct 31, 2014 10:05 am
Forename: Pete
Surname: Cresswell
MGCC Member: Yes
Location: Stone, Staffordshire

Re: Brake drums/drive flange

Post by Peter Cresswell »

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
2020 MG HS Exclusive
2007 Mercedes SLK
Plus 34 other cars since 1965
Rattie
Posts: 3
Joined: Mon Jun 08, 2020 10:30 am
Forename: Vic
Surname: Todman
MGCC Member: Yes
MGOC Member: Yes

Re: Brake drums/drive flange

Post by Rattie »

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