The GMC CCKW

I haven't picked up my truck yet so this information has been given over the phone.

The Data plate on the dash has this information:

Rebuilt by 229th Ordinance Base Depot
Jo# 388033
Shop: 005
Vehicle: CCXW 353
Serial #: (Blank)

Under the dash is another plate covered over with paint. What can be made out is:

Manufacturer Serial # : XXXXXX <-- Stamped out.
We think the numbers under the X's are ?79872

The pump data plate has the following information:

Engineering Stock # 11-4700-255-000
Code: 556
Pump: Centrifugal Gas Driven
Fire Truck Mount
Type: F
Pump# 4

Does this mean anything to anyone?

Neil

If the data tag on the fire wall below the dashboard has been tampered with removed, painted over or damaged you can look on the right frame rail under the right front fender. Behind the shock absorber in 1 inck letters should be stamped your vehicle serial number. Maybe something like this- CCKW 353 79872 B1. (You might have to scrape layers of paint off to see it)
But from what you gave us your truck is a long wheelbase CCKW (your x is actually a K). Not sure if you have timken axles or banjo type. And is your cab the open or closed type?
But if your truck is the one listed on Ebay it is an open cab and it looks like it was a winch model and they removed that and added the pump on the front, and it has Banjo type axles.

It is the one on Ebay. http://tinyurl.com/4lt5s5

It is a long wheelbase (353) open cab CCKW.

Is the Banjo, the split axle type? The owner said Rockwell axles.

Neil

Banjo axles. You can see from the pix.

It has something "funny" plumbed into the front primer fitting on the intake manifold. Not sure what it is. Maybe some sort of vac line to prime the pump? It is kind of large for a prime line.

Pardon my ignorance but what is a Banjo axle?

Neil

A banjo axle is a modern type axle with a removable center section that contains all the gears; ring and pinion and spiders along with all the adjustments and bearings in one compact, self contained unit.

The unit gets it name because the housing w/o the center gear carrier looks like a banjo with a big round center section and (2) tubular 'pipes' extending in both direction from it to the wheels. If it had only one 'pipe' it would look very much like a banjo.

The split on the other hand looks like two funnels bolted together at the widest part over the ring gear. You stand one side up on end and install all the parts except for the pinion gear and bearings, then bolt the two halves together. This was an earlier type with virtually no adjustments. The banjo has many adjustments by comparison like modern axles and the removable center carrier is adjusted on the bench before installation.

The front axle is also quite different out at the steering (ball) knuckle ends. The DUKW could only have been made with the banjo axles due to the superior sealing of the knuckle of the front axle. The sealing of the rear axles on the banjo that keeps the gear oil out of the hubs by contrast is an afterthought (not found on the civy axles of that design by GM) and to put it technically sucks compared to the split design.

The rear brakes on all are semi-self energizing 'Huck brakes'. The fronts on the banjo are Huck (slightly different from the rears) and the splits are Lockheed.

Hope this helps

Speaking of brakes, the owner said the brakes leaked fluid. They worked when filled with brake fluid, then several weeks of sitting later, nothing. Immediately after refilling with brake fluid, they work again.

Is this really bad news?

Neil

Chipmunks!

Sitting = bad

Good news is that it can be saved (probably) by rebuilding the wheel cylinders and master cylinder relatively inexpensively.

Bad news is that it may need a booster $$

When you have the brake drums off, replace the return springs. Cheap insurance at ~$7.95 each and keep the best one under the seat as a spare.

Can a regular mechanic/brake shop rebuild the brakes?
Is this a job that can be done by myself?

This truck runs and has been driven around town recently. The owner did say he relied on the emergency brake and that stopped the truck quickly and reliably. Does that help the situation?

Neil

>Can a regular mechanic

A good (old) mechanic with the manual

>Can a brake shop rebuild the brakes?

NO

>Is this a job that can be done by myself?

Yes if you have ever done brakes before and you have the manual, the time, the tools, and someplace to do it. Until you get into it, you will not know what you are up against. Unless you take the shoutgun approach and order all new parts, it may have to set for a while, jacked up, unmoveable while you get the necessary parts.

Thank you for your help.
I guess I will have to wait and see what happens.

Neil

Neil,

I am currently doing the brakes on my CCKW (when I mean currently I mean right now. I am only inside because there is a Thunderstorm outside and it is raining).

Brakes are easy but involved. I have 2 leaking cylinders but wanted to go through the hubs and brakes before I put it on the road. I ordered up all rebuilt brakes (shoes, cyliinders, and master) from VOV ahead of time. Got springs from Jimmy Carter and had NOS rear hub inner and outer seals on the shelf in case.

When I got into it I found both inner rear wheel seals (modern replacements) leaking actually not fitting properly. They were improper for the application. The outer seals were shot too. The Left rear hub had backed off so it had about 1/2 inch of play in it ruining the original Hyatt barrel bearings that are in there. Had to order in modern tapered bearings from local auto parts store.

Also checked all the wheel cylinders when replacing and they were contaminated with rust.

In synopsis. On one side, now done, I needed all the wheel cylinders, all the inner and outer rear hub seals and bearings one wheel. It has been on jack stands, left side only, for three weeks due to parts ordering, excessive rain, and my available schedule.

The only special tools you will need will be the GMC/Chevy axle nut wrench and the brake spring stretching tool. The latter can be found everywhere the nut tools is probably VOV (Vehicles of Victory).

It is easy to do, gives alot of personal satisfaction, lets you learn more about your truck, and insures that it is safe.

Into this "brake job" so far, I have. Brake parts $800, Bearings $110, Seals $75. It is not inexpensive work.


Bill

When it comes to the wheel cylinders and master, you have a couple choices:

You can rebuild if possible
You can replace with new or NOS
You can have the yours rebushed with brass or stainless steel

If you need to replace them and have the time, have them rebushed with brass or stainless (best). The wheel cylinders fail from the outside in usually due to the fact that they have a metal cap that does not keep the water out so that the outer portion of the cylinder get moist/wet and rusts. As the shoes wear, the rubber cups pass over the these rusty spots and get damaged and the game is all over That does not happen with brass or stainless.

Replace ALL the bleeders with brand new ones ans use anti-sieze compound on the threads before they get wet with brake fluid. Do the same with all the brake threaded components and fittings

If you need a new booster, VOV has a kit with a newer style booster and mounting bracket

When you have the rear wheel cylinders off, use oil or penetrating oil (if they are frozen) and carefully work the wheel cylinder adjusters until they work completely free (they work somewhat stiff due to the spring on the bolt)

Check your check valve up on the manifold (take it apart) to see if it is gummed up inside. If it is, the booster is leaking brake fluid into the engine. This means that the booster needs to be replaced and the check valve must be throughly cleaned or gasoline fumes will kill the new booster. The engine eating brake fluid is not harmful to the engine unless you are using silicone brake fluid. My personal suggestion is to use a good fluid (non-silicone).

I edited my last response. I had the DOT numbers wrong. Sorry

The owner thought the GM axles (Banjo style) underneath the CCKW were the modern Rockwell axles used in the M35, M800, M900 and M1000 series 2 1/2 and 5 ton military trucks. They look kinda simular but the rockwells are top loader differentials while the GM (banjo style) are conventional rear loader style. And Rockwells hav an outout shaft flande on the diff to drive another axle. GM banjo style require andither seperate shaft and pillow block.