TECH: 49-54 Chevrolet Master Cylinder Upgrade

I've been putting off posting this for a while, but I figure now's the right time to do it considering it's TECH WEEK. With all these useful threads going on, I hope this helps.

Now, I'm not 100% positive that this applies to 1949-1952 Chev's, but it's what I did to my '53 210 2dr.

I wanted to upgrade the Brake Master Cylinder without breaking the bank. I didn't really like the bracket kits that used a gutted out stock MC in front of a later dual MC, because it puts the dual MC further back under the floorboard. I know it works, and some people love it, but it wasn't for me. I didn't want a firewall mount setup because I've already smoothed & painted my firewall, and plus, it just doesn't look right to me.


I ran down to the parts store (O'Reilly) and picked up a Dual Reservior Master Cylinder for a 67-72 Chevrolet Truck. This same MC was used on most late 60's-early 70's Chevrolet cars & trucks. Part number is "10-1329" and it was under $15.







I then made a rough pattern from the bottom of the stock MC out of posterboard to make sure everything fit the stock mounting holes in the chassis. I taped it and bent it up, and roughed in some holes for mounting the new dual MC.



Once it fit, I then transferred this to a piece of 3/16" mild steel plate, cut to fit with a plasma cutter and drilled holes for mounting to the chassis & mounting the MC to the plate and bent the upright section over my vise with a big hammer. I left the upright part a little longer than my template because I wasn't sure where it needed to be just yet.



Fitted the new MC to the plate to check for clearance. After test fitting this to the chassis, I realized there was a rivet head on the frame that was hitting the bottom side of the bracket, so I marked the bracket and drilled a slotted hole to clear that rivet.







Then I took a spare stock 1953 MC I had laying around and cut the pivot end off.






Then I needed to make sure the pedals would be in the stock location as they came through the floor, so a 1"x1" piece of square tubing was tacked to the MC bracket near the top, and the pedal pivot section welded to that piece of 1x1.

I compared the new bracket, MC, and pedal assembly to the original MC & pedal assembly I had side-by-side to make sure everything was the same. Mocking everything up with magnets and wedges before any welding. The welds look weird in the pictures, but not in person.







Next I added some side supports to keep everything from flexing when applying the brakes. This was also made of 3/16" plate.





Then I smoothed the mushroom looking end on the stock MC pushrod so that it'd fit in the new dual MC with no binding.



Everything was bolted together and clamped into the vise to check the operation.


No, I'm not using the bolt through the pedal/pushrod, this is for mockup only


Then fit into the stock location on the chassis to check for fitment, and to make sure everything is going to work. Yes there is a giant gaping hole in the floor. This was a previous owners attempt to patch the floor. I cut it out larger so that I could do this conversion as I'll be replacing the floorpans with new panels in the very near future.

Everything fits like it should, the MC is in the stock location, clears the floor with room to spare, and the pedals line up and come through the floor like they should.




All in all, this took an hour or so to do. Keep in mind I built this not knowing how well it would work, so everything is rough. The cutting & welding was done quickly with no care on how it looked because it was a test piece and I didn't want to spend a bunch of time on it. Since I took these pictures a couple months ago, I made a new bracket with quality welds and trimmed & rounded edges, everything is now painted & installed correctly, and it functions flawlessly. On the new bracket, I added two small triangle-shaped 1/4" thick gussets between the pedal pivot and the bracket to ensure there was no stress put on the straight welds across the top & bottom of the 1x1 tubing & pedal pivot section.

Also, this car was a factory manual transmission, so the clutch pedal is also intact on the pivot assembly. If you are using a manual trans, this should still allow you to keep the original pedal & pivot. Since my car has an SBC and 200R4 Automatic, the clutch pedal arm was cut off and unused near the pivot point.

You can run new brake lines, or as I've just done, had a pair of stainless steel braided hoses made about 10" in length with the right fittings on both ends to adapt the old lines to the new MC. The hoses only cost around $17 each and make the installation easy. If I had a lift, I'd replace the brake lines all together, but this is a cheap & quick fix.

 

Actually, this would work on '40 through '54, and maybe still earlier, Chevy cars - the master bolt pattern is the same on all of them. Good idea -

 

nice work great idea

 

thanks

 

great tech

 

A friend at work was just asking me today how to put a dual res. M/C in his 54. I'll hafta show this to him.

But first a question...

Just curious...the casting you welded to is steel? Not cast iron?

Also...I woulda cut the 1" square tube to length and boxed the ends with the gussets. Just a thought.

Neal

 

Great Post

This is gonna Come in useful
Thanks

 

Slicker than snot!!

I'll have to archive this one for my 52!! thanks!

 

Beats me, it cleaned up and welded up nice. These pics were the mock-up piece. I made another one with better welds and more attention to detail/fitment. The ends of the square tubing was capped off on the new one, and gussets welded under the pedal pivot. It seems strong as hell, I'm not worried about it breaking. I didn't have my camera handy when I built the new one, and I painted it up and installed it with a quickness.

Anyone can add their own changes to make it better, but this is just how I did it and figured I'd share. Beats the hell out of paying an assload for a pre-fabbed bracket and having to cut a hole in the floor damn near under the seat!

 

Sorry about that, I was in a hurry.

 

Great post Texas Hardcore !!!

My next project on the poncho was to do this upgrade - now you've made it so much easier - great job !!!!

 

If it works it's got my vote so far!!!!

 

great tech dude!

 

Gotta love tech week. i've been thinging about this for months, and you just simplified things....thanks

 

Cool guys, hope it helps.

Since I installed the new MC in my '53 I have only driven the car around the parking lot to test everything since it is not 100% road legal and I still have other things to do to the rest of the car. It stops much better when I stomp the throttle and go sideways, only to wipe the grin off my face and see a garage door at the end of the industrial park coming fast. The pedal setup and master cylinder are working just as they should. There is no excessive grab or locking up when I hit the brakes, and it's on BFG Silvertown Bias Ply 6.70-15 tires.

 

UPDATE ON PART NUMBERS:

I had my brake hoses custom made at a shop to adapt the new MC to the old hardlines. They supplied me with the fitting I needed to complete this conversion. The hoses braided stainless steel flexible hoses, just like what you have from the chassis to the brake caliper or wheel cylinder. 12" is long enough to loop around and attach the MC to the old lines without any kinking, making the conversion very easy. Looking through a Speedway Motors catalog, I realized you can shave $15 off what I paid at the hot rod store, by ordering through Speedway so I thought I'd share...

Here's a list of what you need:

Quantity-----Part Number-----Item Description
2 #910-31842 12" Long Steel Braided Line- AN3 Fittings (pg 67) $9.99ea
1 #910-318 1/2"-20 IFM to AN3 Male Adapter Fitting (pg 68) $6.99ea
1 #910-318 9/16"-18 IFM to AN3 Male Adapter Fitting (pg 68) $6.99ea
1 #617-4129 3/8"-24 IFF to AN3 Male Adapter Fitting (pg 69) $9.99pr
1 #617-4016 7/16"-24 IFF to AN3 Male Adapter Fitting (pg 69) $9.99pr

Unfortunately the last two fittings listed (#617's) are only sold in pairs through Speedway so you'll have one of each leftover. You can get these at specialty hot rod, race car, performance, hydraulic, and brake supply shops as well.

IFF=Inverted Flare Female
IFM=Inverted Flare Male
AN=ARMY/NAVY Fitting type
3=size of fitting

 

Great tech post...I may do the same to my 54.

 

just surfing thru and caught this one, was thinking of doing my 39 like this now you,v done my homework. will work on a 39. thanx!

 

Nicely innovative. True hot rodding.

 

I was just looking for something like this the other day..
got a single pot MC still on my 53 and would like to do something like this in the near future.
Nice Tech
Thanks

 

useful info...cool

 

saved me 200 dollars. thanks a bunch

 

Welcome! Glad it worked out for ya.

 

I did my 47 Chev the other way, with the gutted out m/c, about 20 years ago. I have some things that are going to redone on the 47, so I might upgrade it to this method.

Nice job, thanks for sharing.

 

I tried this idea for my 49 Chev,only I cut the pivot from the original longer and eliminated the square piece of tube.I then beveled the cut edge of the pivot and lap welded a couple of passes all the way around.It is mounted in the car without lines hooked up and everything operates smoothly with no binding.THANK YOU! for a hot tip.Low buck hot rodding is all a single father can afford,tips like this are priceless.Anyone have a tip for melting three feet of snow?

 

move to warmer area, lol! damn thats alot of snow, we get some but jeez.

this is a great guide thanks for adding your info into it.

 

Puckstopper, I did this all as trial and error, not knowing how it would work out. Cutting the master cylinder pivot section off further leaving more meat, and welding to the plate as you did certainly eliminates the need for the 1x1 sq tubing, and probably looks better. Good job man.

 

That is a damn good idea you came up with , thank you . Im in the process of redoin my brakes on my 49 chevy Fleetline. That will save a ton of $ compared to a original rebuilt MC , plus seperating the front and rear brakes . Did that make a difference (seperating the front and rear) did you need a porportioning valve ?

 

Just curiuos of the welding , did you use a stick or mig? If you used a stick what rod did you use? Or wire if you migged, Welding cat iron to mild steel is what im wondering about . Thanks Very nice thread

 

Kool49, I BELIEVE (anyone else chime in for or against if you know) that the vehicles originally equipped with these master cylinders did not have a proportioning valve, and therefore we would not need one on our cars (I'm going to do this as well). Without seeing the outputs, I would suspect that the brake bias to the front is done either internally, or by larger lines (therefore, more flow) to the front brakes.

Can anyone confirm/deny/expand on my thoughts?