The Stovebolt Site Forums The Parking Lot Big Bolts Master Cylinder for 1956 4400

I just brought home my new 1956 4400 and its a pretty nice truck. There are a few items that need immediate attention such as a leaking master cylinder. I've read so many posts of this site about brakes that my head is spinning but I wanted to get some clarification before I proceed.

The truck will be used on the farm and to move some gravel, rock and dirt from time to time. I need it to be safe and road ready but it won't be used daily or for any type of commercial operation.

From the looks of it, the master cylinder appears to be the original part. Here are my questions and your expertise is greatly appreciated:

Is this a single chamber master cylinder? If so, should I upgrade to a dual cylinder and is anyone aware of any posts that might discuss or show a dual cylinder installation on this model truck?

Should I assume that the hydrovac is also in need of replacement as well? If so, would you recommend having this one rebuilt or purchasing one from a local part store? Being all original is not a big issue for me but I haven't ever had any experience with the quality and reliability of the ones sold by the AutoZone type of stores either.

Here are a few pictures of the truck and the existing master cylinder.

http://s1259.photobucket.com/user/Parksman/media/Full%20Side%20View_zps9wgnhh2n.png.html

http://s1259.photobucket.com/user/Parksman/media/Interior%20View_zpsahintu1a.jpg.html

http://s1259.photobucket.com/user/Parksman/media/Master%20Cylinder_zps88lul4ui.jpg.html

That's a beautiful truck!
Welcome to the Bolt!

Hey new Guy,

Sweet looking truck!

If the vehicle is new to you, it is recommended to go through the entire brake system rebuilding the master cylinder, wheel cylinders, replacing all of the metal lines (yes all, not just the easy ones), and all of the rubber hoses. The single reservoir is fine provided it is a solid tight system. The cost and effort is not that great, and then you will know exactly what you have instead of wondering/guessing/praying. A sedentary lifestyle is terrible on hydraulic brakes, but all too common on old "occasional" use vehicles.

If it were mine, I would keep it stock and simple.

Good luck and welcome.

Paul

Hy parksman, the Raybestos p/n for the master cylinder for your truck is MC21698, hope that helps.

welcome to the site! I agree with Paul, rebuild EVERY COMPONENT of the brake system and it should be fine. Sitting and occasional use is harder on the brake system than daily use. (other than the brake shoes and drums, which wear out).

I'll certainly take the advice and rework the entire brake system. I've got a shop where I can go through it this winter. Would you recommend sending the Hydravac to a re-builder such as White Post Restorations or just purchasing one from the local parts store?

Thanks for the help.

I've bought Hydrovacs from NAPA and from my big truck parts house with no issues. Shop around and see which way is cheaper...don't forget to include shipping costs as part of the total cost if you send it somewhere for rebuilding.

White Post has been around for a LONG time, I wouldn't be afraid to send anything to them.

Mike B

My local NAPA only has parts listing for trucks up to a 3800. Mine is a 56' 4400. Are the wheel cylinders and HydroVac the same on the 4400 as the 3800? Also, does anyone have any problems with Wagner brake parts or should I stay with Raybestos or even look for something different?

1956 truck hydrovacs
1956 truck wheel cylinders

That's good info to have! And it clears up that question. Where do you guys buy your brake parts for the 4400 and larger series trucks?

I had my original master and wheel cylinders resleeved. Shoes were relined locally. Lines bent/flared from 25 foot roll stock.

Some items may be sourced locally if you search by part number versus application.

Have you found a local good "oldtime" auto parts store near you yet? The boys at my auto parts store have helped me find many rare and rather obscure parts.

I located a new Raybestos master cylinder, rear wheel cylinders and rubber lines from an 'oldtime' auto parts store in a nearby town. But they can't get the new wheel cylinders for the front.

Does anyone have a source you'd recommend for new wheel cylinders for the front? Or a part number I could use to start the search with?

Hy parksman, here is an old post about the front wheel cylinder issue among other things. This should give you the explanation and p/ns you need, hope it helps.

https://www.stovebolt.com/ubbthreads/ubbthreads.php/topics/1018651.html

Thanks a million! I'll take that information and get busy finding the remaining parts I need!

You guys are great, great help and I really appreciate it!

It sounds like you are on track to get the brakes rebuilt. I have found a parts manual to be invaluable for sourcing parts. If you know the original part number, online cross reference sites like YOYOPART can aid in finding workable solutions.

Good luck with that nice machine.

With the help of you guys, I have now located and purchased all of the wheel cylinders, rubber lines and master cylinder for my 56' 4400. I shipped the HydroVac to White Post Restorations this morning.

I have 3 questions as I start to tear it all apart this weekend:

I was surprised to find that all of the metal brake lines were 1/4" line. I am certain that it has not been worked on in the past so these would be the factory lines. I bought all of the owners manuals and shop manuals and assembly manual and verified all of the routing to be as shown in these books. But none of them actually give the brake line size. It is my plan to re-do all of the metal lines in 1/4 inch size since this was the factory specification unless you guys give me a recommendation to change that?

There is one rubber line at the rear axle. Is there a reason I should not eliminate that rubber line and go with metal one all the way to the axle and then split over to each set of wheels and eliminate the point of failure from a rubber line?

The vacuum lines that come from the engine and go to the Hydrovac are metal and then have some small sections of rubber hose and then pick back up with metal and then go back to some small sections of rubber hose. Is there anything special about the rubber hose that I need to look for when I replace them? Are they steel reinforced or a special type to avoid any chance of collapse from the vacuum generated by the engine?

Hy parksman, yes there is a very good reason not to eliminate the rear axle flexible line, the rear axle does move up and down and it can twist side to side. There is one quote from a GM engineer that I learned many years ago that I always quote to people when they want to change the factory design "parts left out cost nothing, and cause no service problems" so if there is something on your vehicle it is there for a reason. I always try to follow the factory design unless something more efficient/safer has come along since the original design, hope that helps.

Rubber lines are there to insulate against vibrations and twist. Not a good idea to eliminate them.

I should have known that! It's the only rubber line I was waiting on from NAPA. I will pick it up on Friday.

As always, your expertise and help is invaluable and appreciated.

cross reference numbers from raybestos online catalog and rock auto had everything needed for my 52 4400