Brake Overhaul question

I am going to do an overhaul on the drum brake system on my 1950 Chevy Sport Coupe. It includes new pads, springs, wheel cylinders, rubber lines, etc. I am also replacing all the steel lines on the car at the same time. I have two questions about doing this.

1) What is the procedure for replacing the steel lines on the car without having the master cylinder leaking out all the fluid and letting air into the master cylinder reservior? I just think once I unscrew the steel line from it all the fluid will rush out leaving the master dry.

2) Can I use DOT 5 brake fluid in the system? DOT 5 is silicone based and does not absorb moisture from the air.

Thanks, I appreciate your imput.

 

It is my understanding that you must flush out all the old brake fliud out of all the components, including the master cylinder if you switch to DOT5. Not a trace of the old fluid can remain.

 

don't remove the line from the master cylinder, cut it and fold it over. then remove it when you are ready to connect the new line. if i am changing all the lines i will cut them all, so that a socket can be used to avoid stripping. i myself do not use dot 5 it is nothing but trouble.

 

I would think you would want to get rid of the old fluid in the master cylinder, why push it into your new parts.
Used silicon fluid in a couple of cars once, pedal never felt right. The jug of fluid from the Deuce factory is still sitting on the shelf, untouched in 25+ years.

 

by the time the system is bled all the old would be gone. it just saves having to bench bleed the master.

 

why not rebuild your master cylinder? or get a new one...id hate to do all that then 6 months from now have a bad MC and rebleed etc all of that stuff?

when me and dad did brakes on his 53 we did the entire hydraulic system, didnt do pads/turn drums cause they didnt really need it (recently replaced) we did rubber/steel lines and everything else related

 

Both are correct answers depending on the route you choose.

But since you're in there doing so much work, regardless of what fluid you decide to use, I would flush the entire system. Get the old stuff out.

I assume you are still using the single reservoir, under floor MC?
You may want to look into replacing all of the rubber and gaskets and seals in it also.
Replace the lines. Bleed the system / Bench bleed the MC if you have to with your new fluid.

You will feel better about it in the end. Nothing beets piece of mind knowing you have done everything fresh. It is a relatively easy task to do.

(EDIT....DAMN - oldblue beat me to it!)

 

Sorry, it sounded like he still had the single master cylinder, I've never had to bench bleed one of them.

 

i read "pads" and thought front disc.

 

Youngsters seem to call brake shoes "pads" now a days!

 

i remember when a pad was a place you took girls back to.

 

Hahaha. I just assumed on his older system he "meant" shoes.

Na, you gotta take them to your crib now... I remember when a "crib" was something you put a baby in.

Times are a changing.

 

This car have any upgrades? You can't just go buy new Huck brake wheel cylinders, but if it has Bendix brakes put on it, or a disc conversion and a newer rearend, that's another story.

 

Sorry, meant shoes not pads. The system in the car is all stock with drums all around and a single reservoir master.

 

You really should redo or replace the master. It's very easy to rebuild if it is not badly pitted.

 

Sorry, meant shoes not pads. The system in the car is all stock with drums all around and a single reservoir master.

 

Over hauling the system includes the master cylinder. Think of it this way you wouldn"t overhaul your engine and use the old oil pump would you? The master cylinder is the heart of the brakes.All the work you are doing,wouldn't take that much longer to do the master too.

 

Then I'd suggest throwing the stock brakes in the trash. Converting it to Bendix front brakes using 51-54 backing plates is a bolt on swap. Tons of ways to convert it to a dual-chamber master. Bendix on the rear is a little harder, you have to swap the rearend, but a Powerglide rearend, if you don't have one already, will give you a more favorable gear ratio for highway cruising, and is a bolt-in.

The Huck brakes parts exist for, but you have to reline the shoes and rebuild the wheel cylinders, there are no new ones you can buy. Demand is so low I had some of those parts in decent shape and I scrapped them with the rearend.