Brake drum

From VC-1 to WC64-KD.
egdod
Technician 4th Grade
Technician 4th Grade
Posts: 98
Joined: Wed Apr 30, 2008 8:35 pm
Location: Normandy

Brake drum

Post by egdod »

Hi all, can anyone tell me the maximum size the 3/4 tonne-1 1/2 tonne brake drum can safely be skimmed out too?
User avatar
Gordon_M
Lieutenant General
Lieutenant General
Posts: 2691
Joined: Wed Mar 08, 2006 3:43 pm
Location: Falkirk, Central Scotland

Re: Brake drum

Post by Gordon_M »

I've never had to do it, but because the outside face is cast and probably not perfectly concentric with the bore I'd be more inclined to look at the section thickness at at least four points round the drum, rather than an internal diameter. It's also likely that you wouldn't want to skim it to take out every single internal mark to full depth, unless you were very lucky.
Gordon, in Scotland

( Now officially given up on any form of politics )
egdod
Technician 4th Grade
Technician 4th Grade
Posts: 98
Joined: Wed Apr 30, 2008 8:35 pm
Location: Normandy

Re: Brake drum

Post by egdod »

Hi Gordon, I’m not looking to skim as the drum is in nice nick, I’ve run out of adjustment so need to know if the drum is ok to use with oversize linings.

Dave
User avatar
Gordon_M
Lieutenant General
Lieutenant General
Posts: 2691
Joined: Wed Mar 08, 2006 3:43 pm
Location: Falkirk, Central Scotland

Re: Brake drum

Post by Gordon_M »

If the drum looks good, just go for it, but try to be the same both sides. :thumbup:
Gordon, in Scotland

( Now officially given up on any form of politics )
egdod
Technician 4th Grade
Technician 4th Grade
Posts: 98
Joined: Wed Apr 30, 2008 8:35 pm
Location: Normandy

Re: Brake drum

Post by egdod »

Drum looks good but would be nice to know for sure.
Kaegi
Technical Sergeant
Technical Sergeant
Posts: 1413
Joined: Thu Jan 11, 2007 8:47 pm
Location: Allyn WA

Re: Brake drum

Post by Kaegi »

a brand new drum would be 14.125 or slightly less. maximum diameter is 14.215. some books say 14.185 but I have run them at 14.215 with no heat issues and I used to drive them many many 1000s of miles

and always machine drum when its attached to the hub!!
Ray Edsall
Technical Sergeant
Technical Sergeant
Posts: 1229
Joined: Fri Apr 07, 2006 6:35 am
Location: Australia

Re: Brake drum

Post by Ray Edsall »

G,Day all . My wc53 seems to come to a stop when i take my foot of the accelerator :lol: .If you take your drums to get machined .Tell the machinast that you only want a fraction taken off . Most shops will take every score mark out , There for wasting a lot of metal,and stopping into the future . A few score marks will not matter as the brake shoes will settle down into any groves, that might be in the drum .As new drums are almost extinct ,it is not a good policy to take to much metal off . The drum,s that are on your truck will last a lot longer that way . I seem to recall ,that when the drums get machined past the champher on the edge they are getting to there use by date .Ray
egdod
Technician 4th Grade
Technician 4th Grade
Posts: 98
Joined: Wed Apr 30, 2008 8:35 pm
Location: Normandy

Re: Brake drum

Post by egdod »

Hi, not looking to machine the drums as they are in perfect condition just need the maximum allowable diameter,thanks