Up grading to dual master cylinder

T

tcom

Member
Good morning,

I want to upgrade to a dual cylinder in my '46. A buddy with a '32 roadsters did a very sanitary install of a master cylinder with an integral reservoir. and residual valves. it has a three bolt flange and looks like Mustang (?) unit.

He got it from Roadster Supply. Has anyone installed one in a '46 and if so does anything have to be modified or brackets fabbed?

Thanks,

tony
 
On the 46 the only problem wil be filling it . It needs a slightly larger whole in the floor but it is possible to fill it with a tube if using the original opening in the floor . Of course youll need to separate the line going to the front and install that into the new master .
 
There is this. Don't know anything about it.
https://carrillocustoms.com/collect...ford-3-bolt-master-cylinder-w-dual-reservoirs
Early ford 3 bolt master cylinder w/dual reservoirs

Regular price$119.99all new 3 bolt master cylinders combine tradition and a little modernization for added safety. No more need for a adapter.
Master cylinder is 1” bore. No built in residuals. May need residual valves and proportioning valve added to brake lines.

works with drum/drum and disk/drum.



 
Another option would be a 3to 2 bolt adapter and a regular over the counter Mustang drum/drum master which comes with built in residual valves.

Makes for less plumbing and if you have trouble in the future an easily sourced replacement part.
 
The adapter does place the cylinder further back. Even harder to fill or get the cap off . Third Gen had the 2 bolt old ford style master cyl . I got one from them about 6 months ago . Boy time flies , seems like yesterday.
 
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.
 
Mart said:
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.
Click to expand...

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.
 
rich b said:
...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.
Click to expand...

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+fl...13n-pd-dpltr-ranker_1_20&tag=atomicindus08-20
 
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