VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 Changing Master Cylinder on a 50

Today I changed the Master Cylinder on a '50 for a friend. I had done it before, so knew how to go about it. Never-the-less, by the time I finished, I had concluded that one of several scenarios are likely true:
1. The engineer who designed the location of the Master cylinder was born of parents who were not married at the time of his birth and never did marry.
2. He was angry with mechanics for some unknown reason so decided to leave a lasting legacy for every mechanic for the next 100 years.
3. He never had to change a Master Cylinder except in the laboratory before the engine and body were installed.
4. He was mentally retarded, but then that would be an insult to mentally retarded persons.

I believe he is the same person who designed the center steering pivot with the inaccessible bolt that comes down from the top!

Ron

That same idiot designed a lot of things automotive!!!!!

I hear ya...! That's the same idiot that spent years in college to be an engineer and make everybody else's life miserable without ever getting his hands dirty...

I would say ... all of the 4 scenarios are true.

As an retired mechanical engineer I think his placement of both the master cylinder and the steering pivot attachment is quite logical!

HOWEVER:

I have also taken a few of them out of parts cars. The first one was an after market master cylinder off a 1951 Belair that was sitting on blocks. After a couple of hours I cut the floor and part of the firewall out with a recip-o-saw and used a can of PB Plaster and had the bugger out after cutting the tubing with a small set of bolt cutters. I still have that odd master cylinder somewhere in my shop, just never got around to attempting to rebuilding it...yet.

The last one was my 1953 Belair two door sedan. I did it after removing the transmission (to be replaced with a 1954 3 speed) and the transmission crossmember to replace the pilot bushing, tranny and mount, and the clutch. One of the previus owners had replaced the engine, powerglide transmission and mount with a 1956 truck 235, a 1953 standard shift 3 speed. I had the car on a lift for a week. Everything went okay well almost okay, after I rebuilt the master cylinder and cleaned the cross member and added a new transmission bracket and rubber mount pad with nes bolts, lock washers and nuts. I had to use a tapered punch to line up all the holes Do you know how many bolts are in that stinking crossmember? ... a bunch.

Agree and understand that Master Cylinders under the floor are a pain and don't seem to make much sense, on the face of it. I have thought about this in the past.

Too understand WHY they were there, you have to look at the historical development of the automobile.

In the beginning, brakes were almost an after thought - pioneer cars only achieved speeds of a few miles per hour, so brakes were not much more than a block of wood pressing against a wheel, like a buggy. Usually, this was done by pulling a lever on the side of the cockpit. Sometimes a foot pedal was used, to get better leverage.

As things continued to develop in the early years, brakes were mechanical. You pushed down a pedal, which rotated a cross shaft, which in turn pushed or pulled a set of rods that squeezed a brake band around a drum attached to the rear wheels or drive shaft; and later yet, drums on all 4 wheels (late 1920's on most common American brands). That was quite an advance! - had to be able to apply brakes on wheels that were steering.

By the mid-1930's, the use of hydraulic systems was becoming accepted. Pushing down on the pedal (which everyone had learned to do as the way to stop a car by then) now had to push a rod into a Master Cylinder to build pressure - it was the "Master" of the separate smaller Wheel Cylinders, and "told" them when to push.

But engineering had developed and been accepted as "normal" by then that the brake system was all down on the chassis. Engineers simply inserted a Master Cylinder down there where the pedal already pushed against something. Now it was a hydraulic cylinder instead of a cross shaft. And as cars were built on the assembly line the chassis was a separate, complete system; and a body got sat down on top of it.

Almost certainly, it simply never occurred to anyone that since this new-fangled hydraulic system was now essentially a liquid plumbing system instead of a mechanical system, that they could put the Master Cylinder almost anywhere they wanted to.

Eventually, the light bulb went on, and somebody figured out they could put it up on the firewall with just an extra pivot point linkage.

Of course, this came with a price: now, going down the assembly line, there was more plumbing to have to hook up after the body dropped onto the chassis. But by then (1950's) cars were getting far more complex anyway, and there were many things - mostly electrical - that had to be hooked up after the marriage of body and chassis.

And when you're in the business of building cars, you are far more interested in being able to build them efficiently (less money) than you are about making them easy to work on. Especially something like a Master Cylinder, which would be expected to remain reasonably trouble-free for several years, other than adding fluid - which can be done easily enough when it is under the floor boards.

Yes, I agree with the comments, I was just doing a "Tongue in Cheek" rant on how I was feeling while lying on my back under the car which was dropping dirt in my face, dripping brake fluid from the leaking cylinder and trying unsuccessfully to pull the retainer from the center of the brake and clutch shafts. I am certain that could have been made easier. But as I said, just having a bit of fun.
Ron

When the first master cylinder went on a Chevrolet's firewall there was a big bunch of complaints. Mechanics and so-called experts said "It won't ever work, the brake fluid will geet too hot leake into the fresh air and kill a lot of people, besides you will be having to fill up the reservoir every day."

Hey, Ron -

I totally get it that you were "tongue in cheek" and having a little rant. Lots of jobs seems so small going in, and then kick your butt. And we call it fun - and it is. I just thought it was kind of an interesting topic, because I remember wondering "why'd they put that there?" a few times, and then one day got thinking about it.

Also lots of the words we call things, where they came from, are interesting. The "Firewall" is pretty obvious - keep the potential fire up in front and out of the passenger compartment.

The "Dash Board" comes from horse-and-buggy days, and did NOT mean the same thing as "instrument panel" (there were no instruments yet). It was just a board to, well - lets just politely say - to block the occasional output of the motive power.... so that road apples would dash against it, instead of the people, and fall to the road where they belonged....

I conceed to the logical, progessive developement as involves the location of said master cylinder/s. However, it certainly could (should) have been an easier-to-service design.

I'll stick with what I said above and it applys to early through current models. Example: Remove fuel tank to replace fuel pump! This is both stupid and unnecessary (go look at a Crown Vic fuel tank!).

IMHO, far too many (though not all) of today's automotive engineers obviously change stuff (fixing stuff that ain't broke) simpy in order to justify having/keeping their job/s.

I admit I admire a well educated engineer - - but only if he possesses an equal amount of "horse sense" (without which, he is dangerous!).

I worked on farms, did oil and lubes fixed truck flats on the ground with sledge hammers and tire tools in a filling station, auto salvage yards and kept up my 1930 model A coupe daily driver before I was out of high school. In order to get a college education I drove tank trucks and dump trucks, roughnecked on small and large drilling rigs. so by the time I got out of college I was pretty well trained as to how to work stuff. Mechanical Engineering school helped me learn how to make the stuff and how to make it work effectively to produce work and be productive, some classes that I thought were a waste later paid off The most valuable to this day were the math and physics classes and labs, I also used a lot of the chemistry classes. After I was a district engineer for a few years I recruited mainly EE, ME grads and those that had worked in the real world and those that had military jobs of a technical basis completed their training and were top notch employees that were self starters and didn't quit until the job was finished. The pure academic ones didn't make it thru probation. They could not handle field work without being constantly supervised.
It was Henry Ford that said "If you think you can do something you will, and if you think you can't do something, then you won't."

All points well taken. 'Gotta have some common sense.

In my youth, I worked for a successful sawmill equipment manufacturer. They had a good, competent engineering dept. However, the best educated engineer we had NEVER put anything on paper that would work in the shop! Not even once! There's no telling what he cost the company in rework. A well educated idiot!