Re: Classic Disk Brakes
Posted by Owen_Dyneto On 2015/8/19 11:03:25
The biggest problem with the drum brakes are worn drums and non-original linings. I don't care what anybody says, drum brake linings today are not as effective as the original asbestos. Every low mileage original car I have driven had better brakes than a restored system.
Though it's taken a while, I've gradually come to agree with Tim Cole' comment above, and especially with regard to modern non-asbestos lining materials. Warped drums can be turned true (if within allowable limits) or replaced, and fortunately for those willing to do some work themselves, asbestos lining material, woven or molded, can still be found without too much difficulty. Of course you probably won't find a brake shop to work with this material so you'll be on your own for drilling and riveting linings but this isn't complicated and tools and rivets are common enough. But if the drums have ever been turned the process isn't complete until you have the shoes arc-ground to match the diameter of the drum. I believe correspondent Randy Berger recently obtained asbestos linings and had his shoes arc-ground by a friend of mine to match the drums and I for one will be interested to hear his comments about the brake performance when the car hits the pavement. Unlikely I'll ever drive the Caribbean enough to need another brake reline but I'm thinking seriously of getting some asbestos linings now while I still can, should that eventuality come. In the interim the new Kanter shoes are giving acceptable performance.
Another point which can lead to sub-standard drum brake performance is failure when relining to attend to the (where equipped) adjustment of the eccentric post (as in a "major" brake adjustment). Why folks just slap on shoes and ignore this simple and fast adjustment is probably because they don't read or comprehend the shop manual and/or they just grew up in the disc brake era. Regardless, it can be a very important adjustment and can yield significant improvement in brake performance.
The attached report from Motor Trend does not seem to support Craig's comments that the Packards had more competent brakes than the Clippers, the numbers are (suspiciously?) the same, but curiously the Packard brakes were about best-in-class but the same can't be said for the Clippers where Hudson/Nash were superior.
Attach file:
(121.93 KB)
Though it's taken a while, I've gradually come to agree with Tim Cole' comment above, and especially with regard to modern non-asbestos lining materials. Warped drums can be turned true (if within allowable limits) or replaced, and fortunately for those willing to do some work themselves, asbestos lining material, woven or molded, can still be found without too much difficulty. Of course you probably won't find a brake shop to work with this material so you'll be on your own for drilling and riveting linings but this isn't complicated and tools and rivets are common enough. But if the drums have ever been turned the process isn't complete until you have the shoes arc-ground to match the diameter of the drum. I believe correspondent Randy Berger recently obtained asbestos linings and had his shoes arc-ground by a friend of mine to match the drums and I for one will be interested to hear his comments about the brake performance when the car hits the pavement. Unlikely I'll ever drive the Caribbean enough to need another brake reline but I'm thinking seriously of getting some asbestos linings now while I still can, should that eventuality come. In the interim the new Kanter shoes are giving acceptable performance.
Another point which can lead to sub-standard drum brake performance is failure when relining to attend to the (where equipped) adjustment of the eccentric post (as in a "major" brake adjustment). Why folks just slap on shoes and ignore this simple and fast adjustment is probably because they don't read or comprehend the shop manual and/or they just grew up in the disc brake era. Regardless, it can be a very important adjustment and can yield significant improvement in brake performance.
The attached report from Motor Trend does not seem to support Craig's comments that the Packards had more competent brakes than the Clippers, the numbers are (suspiciously?) the same, but curiously the Packard brakes were about best-in-class but the same can't be said for the Clippers where Hudson/Nash were superior.
Attach file:
(121.93 KB)
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