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Front brake back plate retaining bolt size?

Posted: Mon Aug 26, 2013 9:59 am
by burgundyben
Hi

I am in the process of taking the disc brake conversion off my car and reinstating drum brakes.

Its a 64 car with 8 inch drums.

The back plates have four bolt holes in, 5/16 bolts fit. But the corresponding holes in the stub axle seem to be 3/8ths.

Once its bolted up tight it seems ok but under braking fwd and reverse there will be a tendancy for the backplate to rotate back and forth a little bit?

There's no other alignment feature to keep it in place.

Does this sound right?

Is there another backplate type with bigger bolt holes?

Could I drill out my back plates to 3/8ths and fit bigger bolts?

ta.

Re: Front brake back plate retaining bolt size?

Posted: Mon Aug 26, 2013 12:28 pm
by philthehill
When the disc brake conversion was fitted the 5/16" bolt holes in the upright/swivel were drilled out to 3/8" for the calliper mounting bracket.
The best solution is to drill the brake back plate to 3/8" and use the thin headed bolts previously used for the calliper mounting bracket. Unfortunately there is no other way of getting over the fact that the upright has been drilled for 3/8" bolts. Using the 3/8" bolts will remove any tendency for the back plate to rotate.

Re: Front brake back plate retaining bolt size?

Posted: Thu Aug 29, 2013 12:44 pm
by burgundyben
Phil - sorry for slow response and thanks for answering, albeit not the answer I wanted.

I'll re'drill the backplates and fit the larger bolt size.

Re: Front brake back plate retaining bolt size?

Posted: Thu Aug 29, 2013 3:43 pm
by bmcecosse
It's only going to take about 30 seconds!