The Stovebolt Site Forums The Parking Lot Big Bolts 1950 two ton brakes

I am building a '50 two ton flat bed with a '33 Chevy cab. I will run an '86 292 with an '89 five speed and the two speed rear end. My question is about vacuum assisted brakes. We removed some sort of vacuum accumulator and brake lines from the chassis as it was all rotted out. Is new stuff available to replace it? Was it helpful? Is there a better way? I am using a combination clutch / brake master cylinder from a '60's era Chevy.

The thing you removed was probably a hydrovac. They worked well. Is the master cylinder you are using from a pickup or a 2 ton? If its from a 2 ton, I would use the entire system. Hydrovacs can be bought and parts are still available. Unless you absolutely cannot use mechanical linkage for your clutch, I certainly would hesitate using hydraulic clutch. They were a lot of trouble and therefor were only used a couple of years.

I would avoid using the combined clutch and brake cylinder. they are expensive, and not as common as they once were.

Mechanical clutch linkage is almost always a better idea than hydraulic, less to go wrong and easier to fix on the side of the road.

But the major disadvantage to the combined master cylinder is you can't use a dual circuit brake master cylinder with a direct mounted booster.
The complete original system is not bad, but a newer dual circuit bake system is a much better idea.

If you use the original clutch and brake pedals under the floor you can easily use mechanical clutch linkage and mount a modern booster and dual circuit MC under there too. Makes for a clean firewall too.

Grigg

The mc is for a 1/2 ton, I assume. It is pretty small. The 5 speed out of the '88 half ton utilizes the hydraulic clutch, so I will try it. I respect your opinion about them, but I have had pretty reliable service out of them on several trucks. I think it is worth the risk on this truck, no more miles than I plan to put on it. I am interested in resurecting the hydrovac. It takes one brake line from the original mc and sends it out through front and rear lines. Maybe this will make up for the shortcomings of the small mc / clutch unit. Thank you for your response to my first post!

Grigg,
I got the clutch/ brake mc combo along with a mount bracket and pedals in a kit from an aftermarket company for less than $300. It looks great and I think I will like it better than imagineering the linkage under the floor. Things are a long way from stock under there with the transmission support under the rear of it now rather than right behind the engine. I hope I don't think of you some night beside the road with a flashlight in my teeth wondering why my clutch won't disengage!

Also, based on some advice you recently gave another bolter regarding the two speed, I am using the 5 speed with overdrive. I don't yet know the ratio of 5th gear, but it should be sufficient for 55 mph at less than 3000 rpm.

The main thing (I think) is you should put together a system that is reliable, that you understand, and that you're comfortable working on.
Sounds like you have a plan and are well underway. Assuming you considered your other options and picked what suits you best then go for it.

We all have a different way of approaching our projects, here's part of mine...
When modifying and making changes to my truck I think about the next time I'll have to work on that part of it, can I do it easily, can I find parts later on, is it a good and safe system and idea to start with? What can I do differently to use better parts, make it easier to get to and replace, can the whole thing be any simpler to start with?
Sure I've done and redone different parts of the truck already, and it's not "finished" yet.. Among other things I still want to swap the front axle again.. I'm sure I can make it better next time. But as a consequence I've got a lot of time and money in the truck and it's not done yet, or even legal to drive...
But the hope is that it'll be a truck I can keep and easily rebuild as many times as I need to, it should last longer than I'll ever need it, and hopefully will be fun to operate and service. (try that with a new truck)

So whatever your goal is keep it in mind from the beginning.

Grigg

Grigg,
Thank you again. Good advice.