Technical Disc brake with fruit jar master cylinder

I to-have experienced the failure, rear brakes shoes were wore out, a wheel cylinder piston popped out on a 1965 Mercury, Parking brake was so far out of adjustment, that they didn't work. I drove the car out of the middle of Lincoln NE. When I came to a red light, I had to throw it in reverse, That poor FMX transmission survived and I made the 35 mile drive back to my hometown and survived. I would never use the single pot MC.

 

^^^^^ Mechanical failure or total disregard of PM’s?

 

I run the single master with disc brakes front and drum brakes rear on my 52 Chevy Ute. On the 49-54 Chevy, stock pedals pivot on the master cyl body. So it is not as easy to do dual master conversion and keep stock pedals. I removed the rpv in the master and the system works just fine. No power booster, pedal effort is not excessive, and it stops much better than the stock drums; which is a good thing since driving in today's traffic there are times when quick stops are needed. Yes i have the parking brake connected and working.

 

NO.

 

Do explain why not?

 

It was my sister's car, a hand me down from my older brother. That's what I was going up there for-to bring the car home and repair the brakes. The wheel cylinder piston popped out shortly after I started out of Lincoln. You know how some women are, drive them till they don't go anymore.

 

If you are going with disk brakes in the front and drum in the rear they need different pressures to work properly and to cut off the failing system. KISS !!!!!!
My daddy told me "You can eat any thing in the forest, it"s all according to how sick you wan to get".

 

ok, unfortunately you are wrong but I’ll leave it at that.

Read this…
https://www.jalopyjournal.com/forum/threads/tech-week-57-fargos-brakes-101.1229211/

 

I’ve been running a single cylinder master with drum discs for years……I did this year fab up a e-brake.

 

That's a non-statistic, yet you cannot help leveraging it, as if you are somehow makes you safe, and safer than others.

You aren't, that's the purest form of delusion. It is Russian Roulette Logic.

You absolutely cannot parse the number of deaths per mile traveled, due to brake failure with a single-circuit system in the past, from those of a dual-circuit system today. When singles were outlawed, both roads and automobiles overall far more dangerous than today, yet you confidently, proudly, and unnecessarily want to maintain some of the past dangers. Cross your fingers you are the only one in the accident.

I have analyzed tens-of-thousands of lines of data in OEM records that empirically prove that the chance of a properly designed dual-circuit system failing at-all is statistically indistinguishable from zero, in very stark contrast to single-circuit ones. That's pure, cold statistical analysis. If you dispute that you are just lying to yourself, and sharing the risk with the unwilling.

There is no need for anyone to die to prove that dual-circuit systems are irrefutably better. They save enormous sums in property damage, and non-lethal bodily harm.

Those last two are responsible for raising overall insurance premiums. So, at the very least, and most callous, the basic concern for individually saving money should be enough.

A dual-circuit master cylinder can be had for somewhere between $30 and $70.

That is a small price to pay to make sure that there is a near-zero chance of a round lining up with the hammer.

Just remember, that $30 to $70 is the value that you might be placing on the quality of the remainder of your own life, or that of an innocent bystander, if either of you survive.

 

Gimpy, while I cannot dispute this, I will maintain that a factory single master system is probably better and safer then the vast majority of “upgraded” cobbled together brake systems by so called experts.

 

I guess you missed the point. Even if the brake system never fails, there is still a non-zero chance of those innocent people dying in a car crash. To the tune of 40,000 per year, in this country.

And it has nothing at all to do with how many tubes come out of the master cylinder.

You can delude yourself into thinking that the world would somehow be safe if only I had another tube coming out of my master cylinder, but it's just a delusion. I'm a menace, either way. Mostly having to do with my lack of attention, while driving.

 

It is very clear that there are a whole lot of you that do not have a fundamental understanding of the concept of context-dependent risk aversion, and have never heard of constant absolute risk aversion modeling.

You are choosing your hubris over science.

 

The last year that a new car or light truck could have a single-circuit brake system in the US was 1966.

In 1966, the number of of fatalities per 100-million vehicle-miles-traveled was 5.50.

In 2019, the number of of fatalities per 100-million vehicle-miles-traveled was 1.10.

That's an 80% reduction.

 

Is that because of brake failure's or just "in general"?
If that's a general statistic, there's numerous other safety feature's that could contribute to that reduction.
There's many ways to manipulate the number's to your favor...

 

While I agree with the numbers you quoted I have to wonder about the methodology used to arrive at your final result. I think there are many more factors involved in lowering highway death rates, such as increased seatbelt usage over the last 50 years, crumple zones, air bags and more. All have contributed to lower death rates.
I have had a front brake line go out (it had rusted) as I approached a stop sign in a residential area. I noticed immediately, but only going 25 -30 mph I was able to stop easily. But the way the brakes acted I felt very fortunate that I was not in a high speed situation on the highway, the diminished braking would make a vehicle difficult to stop at higher speeds.

 

I am merely pointing out the folly of taking a "Well people are going to die on the roads anyways, so why should I spend $100 to reduce the risk for all involved?" stance.

That's reckless and callous indifference for life.

 

WE are NOT the problem. WE KNOW what we are doing and what to look for and maintain in our antiquated way's. It's the Jackasses around us that remain the problem, yet WE have to adapt to their ignorance level because WE are the responsible parties. Modern day America is pretty fucked up! PROTECT THE DIPSHIT'S!!!

 

I still ride a bike. LOL

 

Where I live, people will actively try to kill you for doing so.

 

I had the MC fail on my ‘57, damned part was only about 20 years old at the time…I kinda noticed at the first stop sign I came to as the pedal went further down (should have been my first clue, but I was 16). I kinda rolled through the second stop sign. And then woke up and realized my brakes were out.
Being 16 I gave my left arm a workout to get home. It’s not an easy thing to use the “emergency brake” on a TF PU.
There is no stomp pedal, lever on the right side of you, etc.

I’ve never had a dual MC fail, so not sure what would occur. I’ve read you lose stopping power, but must still drive slowly and baby the vehicle home.

Edit: My MC didn’t fail, it was a rear wheel cylinder that went out.
Just needed to set the record straight

 

I think the bottom line here is, if you have a dual master cylinder that is set up and working properly, you have a much smaller likelyhood of being in an accident if you experience an hydraulic brake problem. To deny that is akin to sticking your head in the sand.

If you are in the situation where you need to make a change to your brake system and upgrading to a master cylinder is not included in your changes you are creating a situation that is less safe than it needs to be. Any of your past experiences will not change that fact.

 

Well then nothing has changed in 50 years.

More often than not a dual reservoir master sounds safer than it is. Most of them will bleed across once you get some wear on them. Yes they are still more safe then a single. The only way to survive on the road bike or car is to practice defensive driving. Always know where you are going to go and like someone else mentioned a working e brake in your old hooptie is part of defensive driving. Most of the people reading this will not get this statement, but I am going to say it anyway, "learn to stay alive"

 

Years ago I tore a front brake line off of my OT daily driver from a big piece of ice on the road. The car had a dual master and although the pedal went much lower I still had brakes and was able to drive the 50 miles home without a problem.

 

As for birdman1s question.....
This is my opinion. Option 1 do the research and put a double master on the car to go with those front disc brakes. It's a bigger deal than you think, there's a lot to it.
Option 2, go back to stock with 4 drums and the jar.
If you go disc brakes, go all the way and do it right.
If want simple, stay stock and manage accordingly.

 

Dual verse single, old argument and will never be resolved. But to the Op question about can he use a single bowl cylinder with his disc brake conversion. My concern is that disc brake calipers displace a lot more fluid than wheel cylinders and also the displacement area of the pistons in a caliper are much larger than a wheel cylinder. Does a single jar master supply enough volume and pressure to actuate the calipers as needed? I have no knowledge of how to figure that out, so I always make a point of using a master cylinder that is compatible to the calipers I am using and an adjustable proportioning vale to adjust the rear drums to work accordingly. If someone else knows how to mathematically figure out the science to this, please share that information. Thanks Larry

 

All in here:

https://www.jalopyjournal.com/forum/threads/tech-week-57-fargos-brakes-101.1229211/

 

Great thread Fargo. Of course, me being me, I will have to reread it a half dozen times for it to all sink in! lol I excelled in shop class, not reading comprehension! thanks Larry

 

It was resolved, the moment a dual circuit system was invented, and tested.

Anyone that says otherwise is smoking their shoelaces.

 

I wish I could find a metal lid for my m/c