'63 Front Drum Discard Measurement

[Norm B.]

Norm

[Frank D.]

Re: '63 Front Drum Discard Measurement

It prob doesn't matter what the original "minimal" number is, a reputable modern shop won't turn them down more than whatever the modern spec is...for liability reasons I'm betting; you can get AC/Delco "Professional" series drums all round reasonably and they are excellent. Don't drive with marginal drum brakes; my 63 drum brakes saved my life...

[Ray K.]

Re: '63 Front Drum Discard Measurement

Norm,

The '63 Corvette shop manual does specify the front and rear drum diameter as 11". This is found in the specifications section in the rear of the manual. And as you referenced, a drum must not be rebored more than .060" over the maximum standard diameter.

Ray

[Norm B.]

Re: '63 Front Drum Discard Measurement

Thank you Ray. I never thought to look in the back of the shop manual.

[Duke W.]

Re: '63 Front Drum Discard Measurement

It sounds like you have the original J-65 system. In my experience the shoes last well over 100K miles of normal road driving, but by the time they need replacement, the drums are usually worn beyond further use. Discard diameter is 11.090", so turning to 11.060" is reasonable.

If the shoes are not in need of replacement I've recommended to others to disassemble the system, clean up all the rust and dirt, overhaul/replace all the hydraulic components, and reassemble. Of course the shoes and drums must be marked to be installed back in the exact same position.

Duke

[Norm B.]

Re: '63 Front Drum Discard Measurement

Thanks Duke. Not sure if these are original shoes but they are way beyond reusing. The rears were standard shoes. I have a pair of unused front drums that a friend gifted to me many years ago when he was closing down his parts business but they are aftermarket off shore ones and the more I look at them the more I want to reuse my original drums if they are within spec. By the looks of the condition of the metallic shoes I am not holding out much hope that there is enough meat left on the drums for turning but I will find out in a day or two. I think I will be shopping for a pair of quality drums instead. Since I have the body off for frame rust repair part of the prep before reinstalling is a complete new hydraulic system for the brakes. I am going back to standard shoes because this car is basically just a driver and should never see any spirited driving that would make the metallic shoes advantageous.

Norm