C1 Dual Master Cylinder Conversion ??

[Denny Jacobs]

My '62 is an every "sunny day" driver .... as it is a completely no-numbers matching vehicle. I am seriously considering converting the single master cylinder to the after-market dual master cylinder. This would be done primarily for the safety of the dual system. I am looking forward to the task, as I have rebuilt virtually all of the mechanicals on the vehicle. I have one general and one specific question.

1. If anyone has made this change, can you give me a heads up on some of the problems or any suggestions you may have?

2. I plan to keep the drum brakes front and rear. Can I use the dual master without a proportioning valve? My thought is that the current system uses only one pressure for front and rear axles.

Any help would be much appreciated. Thanks.

[Roy Braatz]

Re: C1 Dual Master Cylinder Conversion ??

Your stock master cylinder should work OK. For 50 plus years cars have used them ! I once put a auxilary vacuum booster inside the left front fender of a 57 and wow was that great. Think about that if you wont an easy pedal.

[Tom Parsons]

Re: C1 Dual Master Cylinder Conversion ??

I think that I would be very inclined to take a hard look at Roy's suggestion and go with a remote booster. If for no other reason, just to keep the underhood a little less cluttered.

[Denny Jacobs]

Roy & Tom, Don't need an "easy pedal" !!

But thanks, at least, for the response. Let's see now, by your theory, cars were available for more than fifty years without seatbelts being standard .... so there should be no reason to use them now. I've had the single master cylinder go out once, without warning. The parking brake really didn't work well. Seems like cheap insurance to add the dual master for a regularly driven vette.
But then, it would not look or be completely "original" ........................ IT IS A DRIVER !!!

[kenneth bingener NCRS#38563]

Re: C1 Dual Master Cylinder Conversion ??

Denny, Search the archives. I looked into this once and there is a lot of info out there on this topic. I chose to stay with the original. There were some problems with hood clearance mentioned. Also remember someone saying that running the line across the front by the radiator was tough to do. Good luck. Ken

[Roy Braatz]

Re: Roy & Tom, Don't need an "easy pedal" !!

Denny! I and others were only giving our opinion of what WE would do. But WHAT you think will make YOU happy is what YOU should do! You ask use a question and we gave you our answers. Please for-give me for answering you.

[Denny Jacobs]

Re: Roy & Tom, Don't need an "easy pedal" !!

Roy,
If you read my original request, I didn't ask for opinions from those who haven't done the change. I simply asked for help from anyone who may have made the swap. But as I stated earlier, thanks for the response.
Denny

[Christopher R.]

Re: C1 Dual Master Cylinder Conversion ??

One of the Corvette magazines did an article on this within the past year. A few things I remembered.

1. You might have some hood interference problems. One way to solve that is by tilting the double m/c down, but that begets pedal linkage problems. Didn't sound unsolvable, just a pain.

2. You need to run the second brake line from the m/c to the existing brake junction fitting over on the passenger side. Chevrolet did the existing single one along the front suspension crossmember, under the engine. Unless you wish to remove the engine, you'll need to run the second brake line under the cowl, down the firewall, and along the frame. A little fussy, but doable.

3. A proportioning valve wasn't used. But I think the authors reserved judgement until they had used the new system for a while. If you're afraid of plumbing in a proportioning valve, you may want to rethink this project because you're going to have to do a fair amount of brake line fabrication in running that second line.

[Tom Parsons]

Re: C1 Dual Master Cylinder Conversion ??

Master Power Brakes has a VERY simple, adjustable proportioning valve. I have installed this on a customer's 57 Vette which I did a front disc conversion on. Seemed to work quite well. The proportioning valve was installed down line of the brake block on the pass side near the battery tray (could be accessed quite easily for adjusting). He elected o start out by only using the original MC, and to date, is still quite happy with the setup.
BUT, NO DOUBT, a dual MC would CERTAINLY be superior over a single MC system.

[Denny Jacobs]

Ken, Chris, & Tom ......Thanks

- I did find previous messages in the archives. They were helpful.
- The latest dual M/C from Power Brakes uses a very low profile bolt on lid. Hopefully, it will clear the hood.
- My thought is to run the rear brake line across the firewall and down to the rear line near the battery.
- The plumbing is not a concern. The reason for not using a prop' valve is because I don't think it will be necessary. If I find it is needed, I will add it in a Chevrolet heartbeat.

Thanks for the messages. I will post my results this spring when I put the car back on the road.

Denny

[Denny Jacobs]

What magazine & issue? Anyone?

Does anyone know the magazine and issue that Chris is referring to?
Thanks,
Denny