'49 Chrysler Power Brake Advice?

[Bryan G]

A possible project for sometime this summer: doing something with the power brake booster for my New Yorker. For those not familiar, this was a factory option, mounted under the floorboard directly beneath the driver's seat. It sits maybe a foot or so behind the master cylinder. 

 

When I acquired my car the vacuum line (long rubber hose up to the intake) was still connected (I've since plugged it.) The brake lines had long since been disconnected. As I recall, it has 3 lines: 1) from sending pressure from the master cylinder to the booster. 2) Sending boosted fluid from the unit to the brake circuit. 3) A return line back to the master cylinder, apparently only there in case of a failure that caused internal leakage. 

 

The first question has to do with #3. The master that was in the car has no place, that I can figure, for the return line. I can't say it is original to the car, but it's no spring chicken. I replaced it with a new production cylinder which is basically the same. Perhaps the original was replaced at some point long ago? I guess a parts book would call it out if there were 2 designs.

 

The second question, is rebuilding one of these units within the realm of a DIY'er? I see that Steel offers the diaphragm:

https://www.steelerubber.com/vacuum-brake-diaphragm-40-0114-24

So could it be as simple a matter of taking it apart, cleaning it out really well and replacing the diaphragm? 

[capt den]

i have the same unit. i had it rebuilt about 2 years ago but have not put it back in the car yet. i would not try to rebuild it myself. the master cylinder for a power brake car has a fitting on the top that allows any fluid that passes the diaphragm in the booster to return to the master. keep in mind that if the diaphragm fails all the brake fluid will get sucked into the engine via the vacuum hose on the booster. horrible smelling smoke will come out your exhaust and you will shortly lose all braking. the power brake master is hard to find. the only difference between it and the manual brake master is the fitting on top that takes a line that goes to the booster. if you want the name of a rebuilder for your booster i will get you mine. not many places do it.    capt den   

[Adam H P15 D30]

Could you replace it with something more available?

[Bryan G]

Good information, Captain. Maybe you can get me the name of that rebuilder? I tried a couple places last year but neither would do it. And, Adam, that looks like a good backup plan. For now I guess I'll seek out the part number for the correct master and see if I can find one.

[capt den]

bryan, i will look in the garage today. not many will do this unit   captden

[Dodgeb4ya]

The 1949 Vacu-Ease brake booster is of an internal valve design and is a one year only...different than the external valve 1950-54 design.

Be careful not to take apart or even attempt to adjust the vacuum/air valve screws...

.The external 1950-54 Vacu-Ease unit will work in place as a complete unit in the 1949 eight cylinder cars if no one will rebuild it.

The smaller style type Midland C-3400....1955-57 Ford/T-Bird cars booster is a good replacement....but with out a core it will be really $$$ expensive.

Edited April 22, 2022 by Dodgeb4ya
correct data

[capt den]

bryan, here is the address for the company that did my unit. mine is a 54 chrysler. power brake exchange, 12405 los nietos rd,santa fe springs, CA,90670   562 756 3727. i paid $400 plus shipping.about a 3 week turn around. yours is a different unit so you  will have to talk to them.   capt den

[James_Douglas]

I thought about using one of the later units in the 1949, but the parts for the valves are not all that easy to get. It is all aluminum or pot zinc.

In the end I opted for the midland ross version and put it in the trunk.

 

I have two complete, apart, 1950 -1945 under the car units sitting around collecting dust...

 

James

[capt den]

did you run the brake lines and vacuum line into and out of the trunk? love to see pictures. what does the midland ross unit look like , what does it cost and where to get it. how did you mount it in the trunk?    capt den

[James_Douglas]

What I did was to run the "master cylinder" line to the "midland ross slave master cylinder" in the left side of the trunk. In the convertible the spare tire rests on the right side of the shelf. We took a stainless steel oven pan and cut it to fit the area and then placed the midland ross unit in it. That way if a leak happens the pan will catch it. I also re-routed the brake light switch to the midland ross unit so that it could be changed without having to get under the car at the left rear frame rail which they did in 1949 on Desoto.

 

From the midland ross unit the lines go out from there to the four corners. I also ran a vacuum line down the passenger side and up into the trunk.

 

You can see I ran a steel line through the trunk wall and the bracket wall (notice the brake line clip) and then added a proportioning valve. I also placed the brake light switch right were you can get to it easy. The painted black stainless steel pan would catch any fluid while changing it. I then made a little plate to cover the area and the result is in the second photo.

 

One can get one of these units from the Ford T-Bird Suppliers.

 

James

[James_Douglas]

A couple more photos....

 

What we did is to make the pan so that the unit would bolt to it. The pan bolted to the trunk externally so the pan is water (fluid) tight. We welded the brackets for mounting the unit to the pan. Any number of variations one could do with this. The stainless baking pans are cheap and easy to get.

 

James