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Jeff Martin
Experienced User
Username: jeff_r_1

Post Number: 92
Registered: 07-2018
Posted on Wednesday, 08 July, 2020 - 22:21:   Edit PostDelete PostView Post/Check IP

I would like to clean up my brake drums, one shoe fell out of alignment when the activator from the piston to the shoe broke and allowed the shoe to wear sideways.
There are now some minor grooves in the drum, before I replace the shoes, I think it would be best to machine the groves out _ probably about 20 thou.

I can't find any specs what the minimum thickness is allowed.

The one shoe had less then a 1/4 of an inch left and there was still plenty of adjustment, so I'm hoping that it's still with in spec.
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carnley3rt@btinternet.com
Unregistered guest
Posted From: 109.156.245.241
Posted on Thursday, 09 July, 2020 - 01:22:   Edit PostDelete PostView Post/Check IP

Service Bulletin BB 198 says that you can machine .050" maximum to 12.300" internal drum diameter.

Download the Service Bulletins from this site, so that I shall have less bother.

(Message approved by david_gore)
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Jeff Martin
Experienced User
Username: jeff_r_1

Post Number: 94
Registered: 07-2018
Posted on Thursday, 09 July, 2020 - 10:30:   Edit PostDelete PostView Post/Check IP

I looked at the service bulletins from Introcar, but they were not there, or I missed it.

Thanks for the info and the link.
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Bill Vatter
Experienced User
Username: bill_vatter

Post Number: 120
Registered: 09-2004
Posted on Friday, 10 July, 2020 - 08:55:   Edit PostDelete PostView Post/Check IP

I am disinclined to machine drums because of minor scoring or circumferential grooves. The linings will wear to match the drums and all will be well. When material is removed from a drum it is gone forever, and the drum is then closer to the machining limit. Adjustment also reaches max travel before the lining becomes worn to the point where it must be replaced. In my opinion, the only time machining is unquestionably needed is when the drum is out of round causing shuddering or pulsing of the braking effect. I suppose it is a judgement call, but I would think again before deciding to cut the drum.
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Jeff Martin
Experienced User
Username: jeff_r_1

Post Number: 95
Registered: 07-2018
Posted on Friday, 10 July, 2020 - 10:53:   Edit PostDelete PostView Post/Check IP

Thanks Bill.
So it turns out that they can't be machined anymore anyway, they are quite a bit past, so that's the way it's going to stay for now.

Even with that, there was still lots of travel for adjustment, the shoe thickness being 1/4 inch on one and less on the other.

I'm not going to worry about.
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Christopher Carnley
Unregistered guest
Posted From: 109.159.182.173
Posted on Friday, 10 July, 2020 - 18:31:   Edit PostDelete PostView Post/Check IP

The problem there Bill, is that when new linings are fitted to scored drums, it takes much longer, if ever, to bed them in.

(Message approved by david_gore)

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