Re: [MV] Enlarged brake drum (potential) problem
Wed, 27 Jan 1999 17:09:47 EST

By refacing your drums oversize, you accomplish 2 things:
1. Weaken the drum quite a bit. (brake drums can shatter under panic stop
situations)(I've seen it on old farm trucks. makes for exciting rides, I
2. cause the new lining to only contact the drum only at the center of the
shoe.(provides a very mushey pedal & extremely poor stopping ability)
Why not just reface the drum back to round & leave the grooves? they aren't
hurting anything & the next time the lining wears out they'll already be
IF you decide to reface them oversize, here are a couple of options:
1.Have the new lining "cam ground". What this does is shave the lining to
match the curvature of the drum.(this is a good idea on anything that has worn
drums & new shoes)
2. when you have your shoes relined, have the ends of the linings shimmed to
match your drums.
These are rather forgotten procedures, but a GOOD old time garage, parts
store or brake warehouse can take care of them. (not Midas)
As far as the longer pushrods are concerned, I don't see any problem with
them. As long as they're not too long.
I can't answer any questions about the rubber parts. I was under the
impression that all brake rubber parts were compatible with silicone fluid.
Didn't Uncle Sam use silicone fluid in the M-715 during Vietnam? He did in
M-151's. Our '66 M-718 (M-151 frontline ambulance)had it in when we got it. My
'61 Ford Falcon (my first car) doesn't seem to have problem with it. I've had
silicone fluid in the original master cylinder for 10 years.
Hope I've helped,
Darryl Bauman Jr
ASE certified mechanic, 23 years experience
certified in: Steering & Suspension
: Brakes & Traction Control(includes ABS)
: Heating & Air conditioning
P.S. I'm still working on the guy with the '68 M-715. Thanks for all of the
input on what to look for & value.

To unsubscribe from the mil-veh mailing list, send the single word
UNSUBSCRIBE in the body of a message to <>.