VCCA Home Forums TECHNICAL - 1945 AND NEWER 1955-1957 …55 brakes

My ”˜55 belair stops okay, but not as good as I would like. I know I could convert to disc brakes, but it’s a show car, and I’d rather not make visible changes. Are there some changes I could make that would not show? Does someone offer a shoe with a different lining that would stop better?
Thanks, Sid

Can you fill us in on the history. When were the brakes last overhauled? Wheel cylinders? Master cylinder? Fluid flushed? Drums turned?

Don't know about the 50s but in the 60s you could order from auto parts special police master cylinders and linings.

NOS brake linings are a good option as the old asbestos linings worked better than modern day equivalent.

As Steve said - brakes are a system so all the pieces need to be considered at the same time and all brought up as close to 100% as possible.

Car sat a lot before I bought it. Only had 150 miles since restoration. Brakes were really bad, so I installed new master cylinder, drums, wheel cylinders about 2 years ago. Car now has 1300 miles on it. It stops okay, but in a tight situation, it could be bad. Sid

"Could be bad ?".........do you mean it takes a lot of pedal pressure and little happens?

I know it doesn’t stop as fast as my newer cars. Yes, more pedal pressure is required, and a power booster would help some, but I’d like to know what other options are available. Thanks, Sid

I doubt that unless you convert to disc brakes and a boosted master cylinder a 1955 car will never stop as well as a modern one.

One key test is to determine if you can lock the wheels in a "panic" stop. If you can, then changing the brake system will not help much unless you change to tires with more grip. Once a tire starts sliding the stopping force actually is reduced.

A 1955 with non-power brakes can lock-up the brakes at 60 Miles per hour.
With the original Treadle Vac power brakes it will be very easy.

If newer non-asbestos brake shoes have been installed a lot of extra pedal pressure will be required.

Thanks guys. I’ll start looking for a treadle vac.
Sid

In my search for a treadle vac I was talking to someone who said he thought ”˜55 chevy cars with standard transmission used a hydro vac. Can someone advise on this?
Sid

The cars with a clutch pedal could not use a Treadlevac so the Hydrovac could be installed. It was a smaller version of the Hydrovac used in big trucks.
If I were going after a moderrn power asisted power brake unit I would look into a dual master cylinder conversion with a modern type vacuum booster. Sold by 1955-57 vendors.
The Treadlevac is a complicated thing that can be very touchy in brake application and expensive to repair I have that option on my 1957.

Yesterday a vendor advised that ”˜55, unlike ”˜56 and ”˜57, used the Treadle-Vac with the oversized brake pedal beside the clutch pedal. ”˜56 and ”˜57 used the Hydro-vac. Any comments?
Sid

The treadle-vac was not ever used on a standard transmission car.
In 1956 and 1957 a hydro-vac was the Chevrolet option for power brakes on a standard trans. car.
There is no room from the clutch linkage on any standard trans. car with the treadle -vac.

Thanks Gene, I thought you would clear the air.
Sid

That same vendor referred me to the ”˜55 assembly manual, which for RPO #412 on sheet 3.00 shows the larger treadle-vac brake pedal beside a clutch pedal. Looks like that would work, but I’m now concerned about the treadle-vac’s dependability. I don’t think I want to go that route now.
Thanks for the help guys.
Sid

I see no clutch linkage or a clutch pedal in that picture.
In the option list it says option 412 available with option 313 only which is Power Glide.
They would not have came out with the hydrovac for standard ransmission cars in 1956 if the tread-vac would have worked. They just did not offer a power brake option for stadard tras. cars in 1955.
If you wre to look under the dash of a power brake Treadl-vac car you would see why there is no room for the clutch parts.

Is there more than one edition of the assembly manual? Sheet 3.00 in my copy is dated 5-1-54 and there are 2 pedals shown in the picture in the middle right of the page, one on either side of the steering column. Maybe this is an error. I don’t plan to buy these parts, especially after Gene said they were problematic. But it sure does look like a clutch pedal in the picture in my manual.
Sid

Mine has the same date. Only thing on the clutch side is the brake line and vacuum reserve tank. The brake pedal does not even show.
Yes, I would not recommend the treadl-vac

I installed he factory treadlle vac on my 1957 P.G. years ago.

You need to talk to the guys at Muscle Car Brakes. The sell a great kit for your car with much better brake pads, self adjusters and bigger wheel cylinders that will meet all of your requirements. Look at their kits online at musclecarbrakes.com

Happy Motoring - Bill

Gene: How do you feel about the hydrovac units?

The Hydrovac works well but is a little touchy.