The GMC CCKW

I have been removing the engine panels from my truck. I noticed the fuel line in this pic had been disconnected. It looked like it had been replaced and the old one just left there. I was about to snip it off when I decided to trace it to the other end.



The other end is in this picture:



Is this an oil pump?

The line continues on to the item in this picture:



The currently attached line dissappears towards the back of the firewall. I haven't traced it yet.

Any ideas on what is going on here?

Neil

thats a gas line going to the fuel pump and before the pump it came from the gas filter before the filter the line goes to your gas tank.

So The new line is going to the gas tank? So that would make the new looking item attached to the gas tank in the picture an electric fuel pump?



Does that mean I don't have a fuel filter in the system?

Neil

I dont think thats a pump . it doesnt like one , to small . The original gas filter is in side that large round item just before the mechanical gas pump.

Neil,

That is one of the two main types of electric pumps. Yours is square the other type is a barrel like.

You want to get a filter pre-pump as the pump will go south if it sucks in enough junk from the tank. I have a clear plastic filter pre-pump and 2 post pump so I can see if there is crud running through the system.

Bill

The line out from my mechanical pump is the one that is pinched off. I suspect because the pump failed at some point. The more I clean and look at the truck, the more modern maintenace items I am seeing. There are new looking cork gasket edges, new oil pressure sensors, new hoses and lines. It is clear that the previous owners cared more about making sure it ran well, rather than being true to maintaining historical accuracy.

Would it be a good idea to reroute the new gas line into the original fuel filter and then to the carb?

Neil

There is a green rubber hose going from the tank to the electric pump. I will get an inline filter and put it there.

Neil

SpookyDad wrote:
Would it be a good idea to reroute the new gas line into the original fuel filter and then to the carb?

Neil

Your question will be answered when you take the original fuel filter apart and check the inside to see how badly it is rusted or gunked up.

My philosophy is the more fuel filters the better (to a point). The electric fuel pump should have no problem overcoming any minor occlusion/restriction of additional filters.

As stated before you need to get one in line at least pre-pump.

Bill

The plastic see through filters are nice but here in Canada some of the insurance companies don't like them . AC Delco is apparently going to discontinue them. It would be a shame to have an insurance claim declined because of such a small item. Use a metal filter and just change it every year as regular maintenance. Easy eh.
Barry

I cleaned everything up on this side. I didn't want to take anything apart as it was still wet. I removed the extra coolant tank. Looking inside it, you can see tubing that goes to two outlets on the side. It is some sort of fire pump heating unit.

You'd best check that fan belt to. It may be new but its the wrong type. With that big fan blade and an alternator it wont be long before it slips.

Now here is the question. Looking at the engine both before and after cleanup. It looks like it is either the "wet olive" or OD green replacement engine. (besides the red over spray) Comments?

It was rebuilt in 1954 but has the original data plate beside it. The serial number is 7505 so that must be a wartime engine. There are many add-on data plates showing a rebuild of '54. All the major components have this.

I did take a closer look at the data plate under the dash and it says delivery date of 3/45

Neil

weasel_nut wrote:

SpookyDad wrote:
Would it be a good idea to reroute the new gas line into the original fuel filter and then to the carb?

Neil

Your question will be answered when you take the original fuel filter apart and check the inside to see how badly it is rusted or gunked up.

My philosophy is the more fuel filters the better (to a point). The electric fuel pump should have no problem overcoming any minor occlusion/restriction of additional filters.

As stated before you need to get one in line at least pre-pump.

Bill

I took off the fuel filter and the filter is completely rusted out. The bowl is badly gunked up but the bowl seems cleanable. I will get a new filter and clean out the bowl.

Neil

His fuel filter brings something to mind:

The other day, I went to start LeRoi and it ran like crap. I took the carb apart and it had some rust particles in it. It is a cast iron carb. I had run it dry last year due to the lousy gas we now have.

Has anyone ever tried or thought of using (very carefully) gas tank sealer on the inside of an iron carb to prevent rust? I might try it on this carb because I have another and it is a simple carb: no acc pump etc. Not too much to screw up.

Comments or ideas?

RE the electric fuel pump.....i would leave them on the truck as well, its a good back up if the mechanical one fails

u can hide it a bit if u want.

Re: the belt...what drive pulley do u have on the alternator..is it a GMC generator size?..the original GMC belt is much wider than modern alternator belts as pictured..i cant see from the pic of alternator pulley size

re r Deuce, the carburettor inside.

i think u could use POR15 or similar to permanently prevent rust particles,
u might have to check the heat rating?

and be careful..that stuff acts like glue on metal, if it got down a drilling or somewhere u did not want, yr carb would be toast

very interesting idea..old carbs get seriously corroded

tony

I am not sure on the pulley or the belt on my truck. It came that way and I haven't had time to focus on that particular item yet.

Neil

They sell wider pulleys for the alternators. Many times they use thread seal locktite on the nut holding the pulley one. One way to get it to release is with a little heat. If you have to heat it, take the front of the alt off after and replace the bearing. You will thank me in the morning....

more comments on inline plastic fuel filters welcomed .... Not sure what my best option is ...my current set up is a disposable plastic one about a foot or so in front of the fuel pump because of the amount of junk coming through I was thinking of putting another near the fuel tank but is there likely to be restriction/constriction issues on fuel flow ....?

My 1945 CCKW (Annie the crane) had a rust problem with the fuel tank. I thought I could out filter the rust replacing the inline filters often and with 2 in series. Wrongo! The rust was so fine it would go thru the filters and mess up the carb. Needless to say, I don't use that tank anymore.