62 disc brake kit recommendations

[Brian B.]

I have a nice, almost all original 62 340hp that I drive a lot in the summer. For safety reasons I'd like to install a disc brake kit on the front only which includes a dual master cylinder and is a direct bolt on. I don't want to modify anything that can't be put back to original, and I want to keep my original wheels. A web search brings up a variety of kits but I've been burned many times by vendors since owning this car and I'd like some direction from the experts in the forum as to specifically what brand / manufacturer, kit ... they would use on their own vehicle, along with any other helpful suggestions. Do i need a dual master cylinder? I drive the car pretty hard and worry about a major failure. Any help is much appreciated.
Brian

[Jim D.]

Re: 62 disc brake kit recommendations

To do it CORRECTLY use a dual master cyl. as well as a disc/drum proportioning valve.

[Bruce B.]

Re: 62 disc brake kit recommendations

Your original wheels will not clear the disc brake calipers in most cases.

[Frank D.]

Re: 62 disc brake kit recommendations

I have a nice, almost all original 62 340hp that I drive a lot in the summer. For safety reasons I'd like to install a disc brake kit on the front only which includes a dual master cylinder and is a direct bolt on. I don't want to modify anything that can't be put back to original, and I want to keep my original wheels. A web search brings up a variety of kits but I've been burned many times by vendors since owning this car and I'd like some direction from the experts in the forum as to specifically what brand / manufacturer, kit ... they would use on their own vehicle, along with any other helpful suggestions. Do i need a dual master cylinder? I drive the car pretty hard and worry about a major failure. Any help is much appreciated.
Brian

You can email bfleckenstein1@earthlink.net or plasticman6145@yahoo.com (Bill Fleckenstein and John Buckman respectively).
They have both done exactly what you want to do on their '62s and they DRIVE their cars.

Bill completed a 9,000 mile trip a few years back with his modified '62...

My '61 was modified by the previous owner with '73 Camaro disc brakes using the original master cylinder and NO proportioning valve (stock wheels fit just fine). The car stops freaky fast, straight and with great front/rear balance - but I don't think it was a kit you can buy...

[Jim D.]

Re: 62 disc brake kit recommendations

My '61 was modified by the previous owner with '73 Camaro disc brakes using the original master cylinder and NO proportioning valve (stock wheels fit just fine). The car stops freaky fast, straight and with great front/rear balance - but I don't think it was a kit you can buy...

You cannot increase the front brake piston area 350% over stock and leave the rest of the system unchanged and make those claims. You posted this same garbage on the CF and was proven wrong by many people that actually know what they're talking about..

[Frank D.]

Re: 62 disc brake kit recommendations

Delco-Morraine calipers off a second generation Camaro, single, original master cylinder, no proportioning valve and stock rear brakes. I've actually driven the car into triple digits speeds around the Sebring track...

The OP is welcome to contact the folks I've recommended that also run similar systems...or not..
I've heard the theoretical arguments before; they don't jive with reality in this particular situation...
I'll stop with that...

[Jim D.]

Re: 62 disc brake kit recommendations

To save you further embarrassment and not having Gary close the thread because of your replies, I'll let the OP do his own research and hopefully disregarding your B.S.

[Frank D.]

Re: 62 disc brake kit recommendations

Mr. Durham (and anybody else) are welcome to examine my car and even drive it...

I also hope the OP does his own research .

I like my setup largely because there is NOT that ugly dual master cylinder that's so out of place in an otherwise original C1 engine bay....
Several TDB forum members know the car, looked it over and seen it driven...

The two email contacts above run similar systems (they are both engineers) and responded in support of me in the CF thread where I was "proven" wrong...

[Terry D.]

Re: 62 disc brake kit recommendations

Brian
This is not the best venue for the advice you need, after all it is a "restoration" society. Check on the Corvette Forum and others. If you insist on this upgrade stick with a good vendor, as homemade setups might work great but they usually entail way more work than stated. I have a 62 with a 425hp crate motor and Tremec 5-speed and drive my car pretty hard and about 7 thousand miles a year. I too thought about disc brakes, but if your brake system is in "new" working order it will stop you. Just my old two cents

[Roger W.]

Re: 62 disc brake kit recommendations

Terry, What crate engine did you install?

[Duke W.]

Re: 62 disc brake kit recommendations

The trouble with most of these "disk brake upgrade kits" is that from what I've heard they are not very well engineered. They may look "pretty" but those who put them together apparently don't have a basic understanding of hydraulics and vehicle dynamics, which is necessary to design a properly balanced system. A disk brake provides brake torque that is approximately proportional to line pressure, but a duo-servo drum's torque increases exponentially with line pressure. Therefore a proportioning valve is usually required.

If one has the basic skills listed above and proper technical data for available components a decent system can be designed, but as with any system it should be tested to ensure that it provides proper performance.

Since drum brake Corvettes use the basic passenger system, but are much lighter than the latter, the brake system is somewhat over-designed. Any drum brake Corvette can easily lock the brakes, and it's ultimately tire adhesion that determines maximum deceleration rate, not the brakes.

My suggestion if you want to ensure maximum reliability is to rebuild the drum brake system to "as new" condition. This will require new or rebuilt wheel cylinders/master cylinder and new hoses. The drums should be checked for proper diameter, and new linings installed. If the drums/linings are in good condition, they can be reused.

Most "brake failures" occur due to internal corrosion in the hydraulic components caused by lack of brake fluid changes over the years, but complete fluid flushes - say every two to five years depending on operation conditions and climate - will keep the system corrosion free and sound for decades, and you can be confident that a single master cylinder system has a very low probability of failure.

Since duo-servo drum systems are self energizing, brake torque increases exponentially with line pressure rather than linearly as with a drum system, so it takes a higher skill level to extract maximum braking without lockup, compared to a modern disk system with ABS.

I learned how to drive at the limit in my SWC with metallic linings and became highly skilled with the J-65 system. Pedal effort is highly non-linear due to both the duo-servo action and the increasing friction coefficient of the linings with high the high temperature that occurs when hot lapping a race track, but they never failed to haul the car down safely from speeds as high as 150 MPH!

Rebuilding a drum system is actually quite inexpensive compared to rebuilding a disk system or "upgrading" the front to disk brakes.

We tend to be spoiled by modern power disk brake systems with ABS. In an emergency you just stomp on the pedal as hard as possible and the system does the rest to bring you to a stop as quickly as possible or drastically slow while steering around an obstacle. Then you get into a vintage Corvette with a drum system and it's a whole other ball game that requires a highly skilled driver to get maximum performance from the brakes without lockup.

I take that as a point of pride.

Duke

[Jim D.]

Re: 62 disc brake kit recommendations

Great post Duke. I've driven my 60 over 70K miles and the drum brakes have never been an issue. I see no advantage to converting to discs.

BTW - I talked to the cam grinder about our conversation last Sunday and he said while a bent cam could theoretically cause the issue, he's never heard of it. They'll check it for run-out when the time comes. Thanks again for your help. It's always a pleasure talking to you.

Jim

[Frank D.]

Re: 62 disc brake kit recommendations

.....My suggestion if you want to ensure maximum reliability is to rebuild the drum brake system to "as new" condition. This will require new or rebuilt wheel cylinders/master cylinder and new hoses. The drums should be checked for proper diameter, and new linings installed. If the drums/linings are in good condition, they can be reused.....

Duke

Precisely what I did when I bought the '63 3 years ago after it had sat idle for 1/2 decade.
I think the cost was around $285 (including new wheel cylinders) all told; compare that to a disc brake "kit".

No issues 12,000 miles later including a few panic stops due to some of the poorer Florida drivers.

Occasionally exercising the self-adjusters and there is no reason not to drive a drum-equipped car in modern traffic.

[Duke W.]

Re: 62 disc brake kit recommendations

I recall a few years ago someone with a J-65 car that had relatively low miles reported evidence that the original J-65 components were still installed with plenty of material on the shoes, but he wanted to rebuild the system for long term reliability. I wasn't surprised as the J-65 mechanical components can easily last well over 100K miles, but the problem is the hydraulics go to hell because guys don't change brake fluid over the years, which causes internal corrosion that can lead to leaks and failure.

Also of note is that by the time the J-65 shoes are worn out, so are the drums, but if there is plenty of material on the shoes, the drums should still be short of the 11.090" wear limit, and as long as there was no pull or premature lock-up prior to disassembly there is no need to turn the drums.

I suggested that he carefully mark the drum and shoe locations (and measure drum ID), then disassemble the system, clean up all the parts, rebuild/replace the wheel cylinders/master cylinder, new brake hoses, flush all the brake pipes with denatured alcohol, then assemble with silicone fluid including assembling all the hydraulic components with silicone fluid that would require them to be disassembled and cleaned of the conventional brake fluid if store-bought new or rebuilt parts were procured and reassembling them again with silicone fluid, and that would include flushing new brake hoses with denatured alcohol.

With essentially all new hydraulics with silicone brake fluid and all the drums/shoes back in their original positions, the system will probably be good for 20-30 years at typical vintage car mileage accumulation even if no brake fluid flushes are done, but even with silicone fluid I recommend flushing every five to ten years to purge the system of rubber wear particle from the seals. That's partly what causes fluid to darken over time. Over time it can result in a sludge at the bottom of the master cylinder reservoir that can plug the compensating port and lead to pedal height issues and loss of performance or sticky master and wheel cylinders.

Duke

[Edward B.]

Re: 62 disc brake kit recommendations

Duke has written wisely, as usual. There is nothing wrong with drum brakes that are working properly. True there may be certain advantages to disc systems in situations that require repeated applications, but these advantages lie not so much in the stopping but rather with the dissipation of heat. For cars that are street driven, restore your Corvette brakes to their original specifications; enjoy the ride and the stopping ability. GM engineers were fairly smart people, even 50 years ago.