Up grading to dual master cylinder

[Mart]

This is just my opinion but you are probably better off maintaining the existing setup. This has been discussed many times here. The ford pedal has a limited amount of stroke due to the through the floor design. Modern cars with swinging pedals have a lot of extra stroke available as the pedal swings under the dash. (some may differ). The chances are that a dual master cylinder, if one side fails, would need more stroke lower down than the early Ford pedal can supply.

[rich b]

Originally Posted by Mart

This is just my opinion but you are probably better off maintaining the existing setup. This has been discussed many times here. The ford pedal has a limited amount of stroke due to the through the floor design. Modern cars with swinging pedals have a lot of extra stroke available as the pedal swings under the dash. (some may differ). The chances are that a dual master cylinder, if one side fails, would need more stroke lower down than the early Ford pedal can supply.

I can verify Mart's post. I found that with a 1" bore Mustang master in my '35 with '39 pedals there was barely, if any, pedal left when "testing".

I then changed to a 1-1/16" bore E-250 that @Mart mentioned in an earlier thread. This set-up had adequate pedal left when "tested" in the same manner.

Also changed out the 1" bore cylinder in my '47 for another E-250 master based on this experience.

Probably never have a problem with the smaller bore master when the brake system is maintained in good condition; but if something happened you might not be as safe as you think.

Being from the land of rusted out brake lines; I have ended up with very little or no brakes when one lets go a couple times. Guess I just want to be sure on my old cars.

[tubman]

Originally Posted by rich b

...Being from the land of rusted out brake lines; I have ended up with very little or no brakes when one lets go a couple times. Guess I just want to be sure on my old cars.

I am from the same "wonderful land" as "Rich B", I can attest to the unreliability of even contemporary dual brake systems. I have a 1999 Ford F150 "beater" truck we usually use for short trips to the dump. About 7 years ago, I lost a rear brake line to rust. The brake warning light came on and I had reasonable braking effect left, certainly enough to complete my trip. A couple of years later, I lost a front line The warning light came on, but I had virtually no brakes at all. I limped to the closest safe place to leave the truck and called for help. Suspecting something more sinister, I replaced the failed piece of line and road-tested it; but everything was fine again. I had learned my lesson and replaced every piece of brake line (along with anything else that looked suspicious). It was a much easier task with the new "Ni-Copp" stuff than it would have been with regular steel lines.

To you guys who are contemplating compromising the original design of your brake system in order to gain what can be of questionable benefit such as a dual master, I would recommend that you reconsider. Your labor will be better spent on maintaining your current system properly than messing up the "geometry" of a factory-designed successful system. When was the last time you flushed your system and replaced the fluid? I have an electronic device that will tell me the moisture content of the fluid. I check every spring before I take my cars out and any one that is even close to the moisture limit gets a fluid flush and change that summer. Along with the fluid check, I perform a visual appraisal of the entire system.

EDIT : It's not that the testers are hard to find or expensive : https://www.amazon.com/s?k=brake+flu...tr-ranker_1_20