Technical 57 Chevy power brake question

Working on my car today and i got to thinking. I've already installed a power brake setup on the car, but I've not ordered a front disc brake kit yet. Would it be completely stupid to run power drum brakes or will it not work period? My original thought was to hook the lines up and not hook vacuum to the servo, just to be able to move the car around, but i thought I'd get some opinions on it. Haven't even pulled the drums yet, do these have ball or tapered bearings?

 

Chevs had ball bearings for yrs but I don’t know when they quit. Good for inline speed. Without vacuum the pedal will be hard but able to stop. I would do it very carefully. There were power drum brakes for years before discs. You will still need to adjust them yourself. Auto adjusting front brakes were known to cause problems.

 

This is a drum/disc setup, dual diaphragm. I don't know if it's even feasible. I think I'm gonna hook it up just to move the car around until i get to the point of changing the front out. I'm not stuck on disc brakes, but updating to tapered bearings is a benefit in my opinion

 

Factory power drums? Or did you add the booster?

 

So would the 57 wheel cylinders "hold up" to the booster?

 

Hmmmmm thanks Mark

 

No that makes you the right one to ask lol. I feel the same way.

 

No worse than a car with power boosted front discs and drum rears .
The line pressure is equal throughout the whole system !

The reality is a booster is used to reduce pedal effort NOT increase line pressure. [otherwise brakes would lock up instantly as you touch them]

 

Makes sense to me! I just wanted to hear somebody else tell me i wasn't be stupid lol

 

I'm running power brakes on my Linc-- stock Lincoln 12" drums up front and 10" Fairlane drums on the rear. Stops great.

 

Yup power drums on my off topic Chrysler and they stop that boat just fine. As said, no change in brake system pressure just helping you push so you don’t have to work so hard! Give them a whirl, you may find discs are not needed. I have more than one old car with four wheel drums, power and non power, never a problem.


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Yeah i have no issues with drum brakes at all, being a lifelong Model A man, I've ran 40's juice brakes on everything I've ever built. I just wanted to be sure that the master/servo setup that I've already hung on the car will work out with the wheel cylinders of the 57. Sounds like it's not an issue so that's the route I'm taking.

 

Mark is correct that there are different masters however the only difference given the same bore size, is the size of the reservoir, the disc one will be bigger so no problem using it with drums.


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Put a power booster on wife's 55 many years ago with stock brakes and stock master cylinder. Drove it daily for many years in Bay are traffic. It stopped just fine with no issues. Only time it was an issue was at the drags after many back to back runs the brakes would get a bit hot and not want to hold it as well when power braking at the line.

 

If the original master had been there i probably would've left it alone lol. It was all gone. The car already had a PS box installed so i got to thinking that if i went on and put power brakes, Mrs. Stone could drive me around and not ***** about the brakes or the steering lol

 

The other factor that may be different is internal residual valves


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Do you mean the absence of? If i have bleed off issues I'll install some in line.

 

Be damn-sure you carefully inspect the wheel cylinders, before pressing on with the power set-up! Hell, it wasn't until after I did a rear brake job, I realized I had driven my '57 with ONLY front brakes, for nearly 5 years. I bought the car out of Tuson, and both rear cylinders were caked with desert dust... HO-le-****!!!

I highly recommend you go on Facebook, connect with us troops on the Tri-Five Chevys International page. Steve Blades is the head kahuna there, might even be a neighbor of yours. Lots of sage wisdom there...

IF you can't get the parts you need locally, take a look at rockauto.com - hard to beat their prices! For '57 stuff, put s shout out to the TFCI gang, you'd be suprised how quick pieces turn up! Good Luck, Tim

 

Yeah I'll go through the entire system. I don't half *** anything the wife and kids ride in

 

If they are there they will be 2 lb for the disc side and you need 10lb for the drums, with drum brakes the residual valve is there to keep the cups in the wheel cylinders expanded so they don’t collapse and let air in upon brake release. Some wheel cylinders have cup expanders in them eliminating the need for the residual valves.


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Something to think about, I'll check that after i get it all plumbed. I've used this same master on other cars and not had any issues. Fingers crossed

 

To answer this. All Tri-5's [& 58's] have ball bearings.
So if your Chevy still has the rivets holding the drums on, it will have Ball bearings.

They are easy to convert to tapered roller bearings! You need some hubs off a 61-68 full size Chevy and they go straight on. [grind off the rivets and swap the drums]

If you keep the ball bearings [which are reliable enough to have survived 62 years so far] just remember there is a proper re-torquing procedure that must be followed .

 

You have the same master cylinder I used, looks like what is called Corvette style. I don't think it has any residual valves built in, and with it mounted up on the firewall you won't need them. They are used when the master is mounted under the floor, lower than the wheel cylinders.

 

Yeah i checked tonight, hoping that somebody had already upgraded it. No luck. Like you said, 62 year old bearings. And what I've priced ain't cheap to replace. Plus the replacements wouldn't be near the quality. Not a lot of donor cars sitting around here so I'm gonna order the aftermarket hubs. Thanks for the info

 

This is partially false, they are also used with drum brakes where the wheel cylinders do not have cup expanders. When the brakes are released the return springs pull the shoes back pushing the pistons into the wheel cylinders which causes the cup seals to collapse partially due to a low pressure in front of them, this can allow air past the cup seals. Residual valves keep the cup seals sealed, that’s why drum brakes need 10 lb valves. Unless as I said before, the wheel cylinders are built with cup expanders. When the master is lower than the wheels the residual valves also act as a check valve.


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