The Stovebolt Site Forums The Parking Lot Big Bolts 1951 chevy 1.5 ton Brakes

Hey guys, i just brought home my first old timer on Ebay \
i cant wait to get started on this project.
The engine starts right up and runs great!

However, I have a big problem with the brakes as there isnt any. i dont know anything about this truck, so forgive me in advance. I can put brake fluid in what i believe is the master cylender under the driver side floor and it just leaks out. i looked further and there is only one outlet brakeline that splits front to back. Is that normal? It seems dangerous if you break a line. Anyway's where do i start? can i mount a 80's master on the firwall and run that? can i get a new/rebuilt one? anyone have one to sell? i have many more questions, but i would like to get it drivable first.

Welcome to the Stovebolt!

Not a bad find for what you appear to have paid for it.

A single cylinder master was common until Federal law mandated a dual master starting in '67 or '68. A hydravac which boosted braking power was an option on your truck, but from your brief description I suspect yours does not have it.

Where do you start?

Start by figuring out what you want to do with the truck. How you are going to use and drive it, how you will load it, what your performance expectations are going to be. Think those things through and try to summarize in just a sentence or two.

I say that because I believe the best approach to your brake problem could differ quite a bit based on your answers.

Give that truck a brake.
Pull the master cyl,pull the wheels off and pull the wheel cyl. which will allow you to also check the brake linings.
REBUILD or REPLACE what is necessary.

I say that because when I bought my truck I drove it home with some brakes, tore it down to find out the rears were froze and the only brake I had was the fronts and the front cyls were in bad shape.
I know it's a lot of work plus money, but how else will you know what the true condition of the entire brake system is, plus your life my depend on those brakes someday.
Depending on how you intend on using the truck will dictate possible upgrades to the system.
Dan

I drove mine home with brakes also, but I was lucky they didn't fail. They did later on my property. I also suggest you take the brakes apart and rebuild everything. I went with new everything, including the hydrovac. You can get the following books through several of the vendors at the links page of this site, a build book, a parts book, and a repair manual. I think these are also in digital format at, http://chevy.oldcarmanualproject.com/. Take lots of digital pictures as you take things apart, and keep your parts in marked baggies or boxes. My two favourite vendors for getting parts were The Filling Station, and Jim Carter. If you need new bearings, you will find the fronts difficult to find. It drove me crazy finding them. A lot of guys suggest getting your brake cylinders and master cylinder sleeved. YOu can do a search and read about it. Have fun with your new big bolt, and be safe.

Wow, you guys reply quick!

Well my plans are, I have a 5 acre woods, and a newly built house. I am planning on building a pole barn, ect. I am a major do-it yourself guy, so i ended up buying a bobcat and a wood chipper with a 8 cylinder 318 big boy. I originally was looking to buy a small dump trailer, and instead found this bad boy. I have always wanted a 40's/50's pickup and needed something to haul small loads so now I have both.

So to answer the question, I just want to be able to move some firewood on my property, get small loads of stone and pull my bobcat trailer around town if needed. The truck has some pretty bad rust on the side cowl, and the fenders are very thin on top with some holes. Im going to try my hand a some body work. I have a torch, welder, cutting tools, ect. So I don’t mind fabricating at all. I cant see going to a car show or anything . I also want to keep my cost in line, so keeping it original isn’t a major issue to me. I just want it to work.

I would love to fix it up as more of a rat rod but im not sure if a dump truck would be that "cool"?

I think that there is no question that you will have to either rebuild or replace the wheel and master cylinder and brake hoses.
You can inspect the drums and lining. The original setup worked fine for many years. I drove single brakes for many years when thats all we had and I still have them on all of my old jalopies. However, if the single system worries you, I would replace it. A person must have confidence in his brakes. You can get kits that mount under the cab like your original master cylinder. Its easier than trying to fabricate linkage for a firewall mount. Once you get it running and stopping good, you can decide how much body work you want to do.

I saw a couple of important things in your intended usage. No swap to a bigger motor, and pulling a trailer with a bobcat on it. Thanks for clarifying your plans. I've answered questions enough times about how to fix or modify the stock parts only to get a reply along the lines of 'oh, this is going to be a rat rod...'

A rat rod dump truck would not be very practical whether it was cool or not. The only way I can think of to lower the dump box would require tubbing the dump. You would lower your load capacity and might adversely impact dumping. Interesting to think about, but again, not very practical.

If you stay with a stock motor you aren't going to move very fast. That would suggest stock brakes are good enough. But pulling the trailer with the bobcat argues the other way--you want the brakes good enough to stop that loaded trailer when some kid on a bicycle darts in front of you.

So my two cents is spend the bucks to make the stock brakes as good as they can be including replacing all the brake lines. Also consider either adding the hydravac unit or a power boosted dual master.

With a load of dirt or rock in the dump and the bobcat behind you aren't going to move very fast. But you'll sure want to be able to choose where it stops.

I agree with Steve's assessment,
New lines, cylinders/kits, shoes, and most likely an under floor dual master cylinder with vacuum booster.

Your plan sounds reasonable as far as use goes, it'll be slow but just fine for "around town".

Update the truck to 12 volts if you haven't already, and get a good electric trailer brake controller to work the brakes you should have on the trailer.

Grigg

just to clearify, when i said rat rod, i wasnt considering, lowering the front end, or getting extreame in anyway... I was more talking going with a satin black, simple clean, I am missing most of the chrome if there was any to begin with... I guess i was saying im not fooling myself by thinking this will be worth a whole lot in the end if i keep it bone stock. I live near the city and most of the time you dont get up to 50 mph. Also, i was thinking the electric brakes on my trailer would assist. I pull it now with a 1/2 ton dodge just fine.

Can someone steer me in the right direction as to some part numbers, or year make vehicle that my have come with a dual cylender master that i can buy localy or online? I went to napa and they just staired at me when is said 51 1.5 ton chevy.

I've seen some pretty extreme rods that started out as real trucks. I understood you weren't headed that way.

Grigg's suggestion of converting to 12 volts is a good one. I just assumed the brake controller and didn't stop to think your truck is probably still 6 volt. I worry about trailer brakes failing and like my trucks big enough to stop the trailer without the trailer brakes if needed.

Its unlikely you'll find a dual master that can be mounted the same way the stock master is. The usual approach is to buy or make a bracket that mounts a modern dual master. Most the old truck vendors carry one and last time I bought it was less than $100.

Then of course you still need an appropriate booster and master cylinder. I'm thinking the best answer might be something off a '68 to '70 (first years with dual master but before disk brakes) Chevy or GMC bigger than a C-30 but someone else may jump in with more knowledge or a better idea.

I dont know where most of these guys went to get parts for theirs but we went to jimcartertruck.com and they have just about everything for the trucks that you will need.

What ever you do make sure the Master Cylinder is designed for a 1-1/2 ton truck. The MC for the 1/2 ton trucks (sold by all of the vendors) has a small bore and will not work on the big trucks.

Mike B