The Stovebolt Site Forums The Parking Lot Big Bolts 1956 4100 rear brakes Where?!?

My son was given a 1956 4100 that loading it on the trailer I stomped the brakes and it covered the brake shoes in brake fluid, plus I think the hub is leaking axle grease into the brakes. It's the original diff. So where do I get parts for this diff and brake system? Really don't want to replace the diff.

Hy John Thomas, welcome, when you start taking things apart ask us specific questions about which parts you are looking for. If your brake linings have been contaminated with oil or brake fluid, it is best to replace them. Good luck with your project.

I can tell you what i did because my brake shoes were soaked in oil i know its not the best thing to do but we shall see what happens. I cleaned mine real good with brake cleaner till they looked clean, I then baked them in my powder coating oven at 400 degrees for 2 hours. That baked the rest of the oil out of the shoes i then scuffed the shoe with sand paper. If they were readily available i would have changed them but worked with what i had on hand.

wickedinhere Sounds like a good clean-up I use the cutting torch (carefully) to attain the 400 degrees-or less. Done it on big off-road trucks so not as critical.

Thank you wicked! I had decided to soak the shoes in power purple degreaser to hopefully allow the oil to leach out and plan to use the oven when my wife's at work to bake the shoes to dry them out. What do you think? Next issue is axel tube seals. Any idea what they are? Can't even begin to put it together till that's fixed. I found new wheel cylinders on line and springs(hesitating to buy springs till I take the truck apart.) Also I'd like to rebuild the original ones for spares if I can find the rebuild kit. This is a brake setup I've never seen before with two wheel cylinders per side so I'm going slow and have threatened my son's life if he takes it apart without fully photographing it prior. I stripped a set of 19.5 inch rims off a rv at the pick and pull that fit nicely. Next question is are the front brakes the same as the 3800 axle? Moving on up I'm assured that a vacuum booster won't fit in the space under the floor with the transmission and I'm not really convinced but not sure enough to gamble $350. So I'm thinking a hydraulic booster and dual master cylinder. But that requires a power steering pump and I'd rather not if I can fit a vacuum booster. Alternatively I had the thought of rebuilding the hydrovac and putting it on the rear brakes and using a manual dual master cylinder but am unsure if this would work safely. Any thoughts?

Any competent big truck shop should be able to send your brake shoes out for relining. Trying to fix brake fluid or grease-soaked linings is a total waste of time and effort, no matter what Mr. Bad Wrench on some website claims. Betting one's life on Mickey Mouse brake work puts everyone in danger- - -yourself and everyone who has the misfortune of sharing the road with you. Try NAPA for hydraulic repair parts such as wheel cylinders and a rebuilt hydrovac, and restore the brakes to perfect original equipment shape, unless you have a degree in automotive engineering and the research and development facilitles to totally redesign the brakes. The guys who designed that system weren't dummies who just fell off a turnip truck! Do you intend to do real truck stuff when you're done, or just cruise around to tailgate parties and car shows with an iced-down Yeti cooler full of Bud Light as the only cargo?
Jerry

Good points Jerry I'm for keeping OE except the in my opinion valid point of needing a dual master cylinder. Then which side do you connect the hydrovac to and or add a second hydrovac? I don't have a spare to add to the system do you? Additionally my hydrovac needs a rebuild that in my research I've found to be around $400. At which point a dual master cylinder with a hydraulic booster is sounding pretty good. I intend to use it generally as a beefy 1/2 ton truck but am not opposed to the occasional parade and I lack the yeti full of beer but have found that a $14 cooler from Walmart keeps them from rolling around in the bed just as well and if they get hot i figure I didn't drink them fast enough.

When you pull it apart look closely at the axle seal it should have a number on it and you can google it to cross reference to another suppliers part number thats what i did. Yes dual wheel cylinders in the rear like mine my first time with this setup also its not bad to do worst part is cleaning all the parts.LOL

If I can't convince you to go back with the original equipment system, I'm sort of wasting my time. I really don't know of a dual chamber master cylinder with enough volume to effectively operate wheel cylinders the size of the ones you have on that rig, so whatever method of power boost you choose will be irrelevant. You will run out of pedal stroke long before all the brakes get applied. Untold thousands of those trucks hauled maximum loads for millions of miles, and I doubt if very many of them which were properly maintained had a catastrophic brake failure. The proper size hydrovac was designed to handle max-load situations and provide adequate stopping power. Reinventing the wheel seldom has good results.

Check into what a good civil suit lawyer will charge per hour to defend you when your Rube Goldberg brake system fails. A $400.00 hydrovac is cheap liability insurance.
Jerry

There is no mix and match with braking. There is nothing wrong with a hydrovac. Our gasoline tank wagons in the 1950s all had a hydrovac and they would stop like air brakes. There is no reason to have a dual master cylinder. If you have a hydrovac on the rear only the rear whels will lock up and you will switch ends before you know what happened. Just get some oil seals, rebuild your wheel and master cylinder, have your hydrovac rebuilt and your shoes relined, replace hoses and inspect or replace lines and you will have brakes that work. My father started in the gasoline business in the 1930's and I grew up with gasoline tank wagons. I bought my first semi in 1964 and I still own a dozen semis. I have learned a lot in these years. Brakes worked fine 65 years ago on 1 1/2 ton trucks and they still will if you don't screw them up with crazy ideas.

Tore into the hub assembly/ brakes on the 56 today the axel seal is a victor 49904 which crosses to a national 6358 and they were $11.95 on Amazon! As soon as I can take the remaing wheels and driveshaft brake apart I'm planning to send them to Indiana for relining.

So the left hand side has one of the star wheels corroded up so I can't seem to get the drum off currently using copious quantities of pb blaster to try and losen it up.

All of mine were froze i couldnt get them to budge i had to use a puller for one drums then once the drums are off you can really soak them in pb blaster. You can then work them back and fourth with vice grips they will free up just use anti seeze when you put them back.

Remove the rear axle shaft and the bearing retaining nuts, and use a crowfoot puller to take the hub and drum assembly off together. Use a socket the diameter of the axle load tube to push against with the puller screw.
Jerry

Thanks Hotrod that worked great! I had to fabricobble a wider spreader bar for my puller but in the end it came off with little effort tge brake shoes and parking brake are on their way to Indiana. After I recover monetarily the hydrovac will be headed to California for a rebuild and in the mean time the frame is getting rust converter and painted while there aren't any brake lines or wires in the way to get painted. Everybody gets a bath and a paint job before they get put back in their place. New wheel cylinders, new brake lines and new master cylinder complete project stop darn you!

A simpler method is to use the axle bolt holes or studs as an anchor point for the puller. The same one I use for harmonic balancers is almost exactly the right size for rear hubs on amything but the really big rigs, and most of them slide off the load tube easily by using a grease plate on the floor and leaving the tires mounted.
Jerry