Master cylinder mounting, firewall or under cab?

Which is more traditional, mounting the master cylinder under the floor, or on the firewall? This is on my 36 Dodge pu with the o/t frame. I've been looking at some of the old pics and it seem to have been done both ways. Also been looking at the kits Speedway offers, under cab is cheaper, but it looks like maybe the firewall mount might be easier. I am not planning on running a booster, but might change my mind later. I have a donor 99 Ranger that is giving me a 8.8 rear, and can get the master and pedal assembly if I want it to run instead of the pre made stuff.

I like the look of a clean firewall with nothing in the way of the engine, but then again if it works better on the firewall, I'll go that route. Thoughts and suggestions?

 

If your vehicle is on an O/T frame, why be concerned with attempting to remain traditional? That ship has already sailed...

 

6 of one, half dozen of another. Functionally, both ways can work just the same if engineered correctly, but cosmetically, ones hidden under the floor just clean things up a little more. You are right, there were a lot of cars built in the day with either the squarish Chevy pickup mc or one or two Ford type mc's on the firewall, and a lot with them under the floor too.

One possibility when using the under floor version is that you "might" need residual valves to keep the fluid from draining back, especially if the mc is mounted lower than the wheel cylinders. But I have an underfloor Chevy pickup dual mc on my 27 and have never needed the residual valves on it.

A third option these days is one of the Kugel Komponents 90 degree under dash units. While not strictly "traditional" it can solve the problem if you don't have room under the floor and still do not want mc's hanging on the firewall. All you see is the hanging pedal so unless someone stands on their head under your dash they will never know what is there anyway.

Don

 

if there is clearance issues a remote reservoir is an option - information here http://www.apracing.com/info/index.asp?section=master+cylinders_2350

 

The traditional way when I started was to take the swinging pedal out of a 50s car along with the bracing and use it. Look at a lot of old pictures and you will probably see dual M/cyls mounted on the firewall. Putting the M/cyl under the floor is a modern (70s) thing to clean up the firewall at the start of the billet craze. The Chevy truck combination M/cyl was popular in the early days with aftermarket swinging pedals made just for this purpose. I must say that I prefer the clean firewall but in the early 60 I'd see more cars/trucks with an engine compartment like the one above with Mcyl, fuel pump and ballast resister on the firewall than the super clean ones popular today with all the mechanical components hidden out of sight. I guess it all comes down to how authentic do you want to be?

 

That truck? Firewall. Ever try topping off your brake fluid through a hole in the floor on a breezy day? I'll leave that joy to the traditional boys.

 

Tommy nailed it. All cars had the brakes under the floor until the 1952 Ford came out with swinging pedals. For a while hot rodders copied the new look, with the double side by side master cylinder ( brake and hydraulic clutch).

I think it was show cars in the sixties that first went in for the clean firewall look.

 

Glad you started this thread ... Iam helping my buddy change his 34 ford to juce brakes and were useing the old orginal brake pedal ... Where do you guys with these old Fords mount youre master cylinders ? We want to mount it under the floor ... Any body got any pictures ?

 

I agree, it's not going to be 100% traditional, but it was already on the o/t frame when I bought it and I'm using what I have. I'm sure some of the old builds were done on different frames. Just because something is different doesn't make it better or worse, just different.
There is a difference in slick smooth billet filled rods and homebuilt out of what works though. No billet on mine, very little chrome and it will be painted. If everybody built a car the same way, it would be boring.

 

Firewall is easier, I have two cars with it under and one on the firewall. The under the floor ones are real tight to the transmission and crossmembers for what it's worth.

 

I stole this picture off the web for the special dual quad air cleaners but it has the typical dual Mcyls that made clutch linkage so much easier back then. I think I still have the inside pedal assembly around here someplace that I harvested from some poor old parts car so many years ago.

 

You completely and totally missed my point. Nobody is attempting to explain to you what's what....
Build it, drive it, enjoy it, do whatever makes you feel all warm and fuzzy.

 

No problem Special Ed. Just trying to do the best I can with what I've got to work with.

 

Hmmmmmmm, "Doing the best you can with what you have to work with."

Sounds like hot rodding to me !!


Don

 

What Tommy said... I took the pedal and bracket assembly and master cylinder out of a 55 DeSoto for my current coupe...

 

i always liked the master cylinder under the hood. "hidden" stuff is just a pain, nothing worse than having to remove upholstery/carpet to work on your car. my thought is that is what the engine compartment is for.

 

I like them on the firewall too. I like the mechanical look of stuff on there, its artistic. That said, my brake setup is under the floor in my 34 pickup.

 

Easier to work on on the firewall, if you're going to drive the car and work on the car I'd put it there. If you're going to trailer it to shows or pay someone else to work on it, then hide it wherever it will fit.

 

My old jeep had one under the floor, PITA.

 

I'd put it on the firewall if you have room......

 

Thanks for all the replies. It looks like the firewall it is. It will be a whole lot easier to build the floor with it up there, too.

 

Exactly! I love those little details like the chromed reservoirs on the firewall, the big honkin generator brackets, the high mounted headlights etc. It really comes down to how much you love the ways of yesteryear. I'd like to run a Chrome reservoir on my '32 eventually however I'm always weary of single MC's....especially after hearing stories like Weez's 29 getting hit. I will tell you that on the Firewall is so much easier to service and bleed compared to under the floor.

 

If putting it under the floor, be aware to keep your exhaust pipe away from it. I put my '37 Plymouth's MC under the floor, I used a 'Y' pipe exhaust, ran one exhaust pipe down the passenger side, then split it back into dual exhaust in front of the rear axle.

 

If youre going to put it on the fire wall you may have to weld a 3/16 plate there to help support the MC ...

 

i'm going with a 180 degree kugel on my 50 starlight. SWEET !!!

 

X2. But like Don said, if its already got a late model chassis, isnt it a little late in the game to worry about whether your swing pedal install is period? Sorta seems like putting 3 97's on a 302 Ford to me...

 

For me on the firewall is the only way to go. Have you ever tried to fill the cylinder when under thr floor? What a pain in the ass. Also you will need residual valves if the cylinder is under the floor. Just my 2 cents worth

 

Good idea, thanks for the advice!

Good point I hadn't thought about. I guess I'm overthinking this thing. I'll just have work this thing out and quit worrying if it's period correct or not since it won't be. I just don't want to do anything stupid that will deter from the looks or driveabilty of the truck when it's done.

 

I prefer swing pedals, but I grew up with sixties era cars, so its what I'm used to. I would mount it on the firewall because its easier to work on.

 

My '41 ford has the M/C under the floor. #1- is kind of a pain in the ass to check #2- don't believe you can get as much leverage with a under floor mount, or at least it feels that way
#3- firewall mounted M/C require extra bracing to eliminate firewall flex