M37 fuel pump and carb problems

[gonorth]

I bought a couple of M37 last Saturday. Pics and story are at the link below if you need to see them. These vehicles are in excellent shape but have been stored indoors for at least 20 years. I knew the previous owner and an confident that these ran when put into storage.

I oiled the pistons via the plug holes before cranking, put in new plugs, changed oil. I messed up the plug wire to the front plug so that is a cobbled onto the plug, that may be a in issue yet. Is it possible to redo the end of one of those cables or am I stuck buying a new cable?

First the fuel pump. I drained the fuel tank and put in fresh. Then sucked the new fuel up the line at the fitting going into the carb. The primer lever on the fuel pump does not work, has very little resistance when you move it. I was getting a little fuel out of the line to the carb when I cranked it but now there is nothing. So, any ideas what I am in for with the fuel pump?

Second is the carb. I can get the thing to run while spraying carb cleaner in the mouth of the carb. I hooked up a boat gas tank to where the pipe from the pump would go into the carb and squeezed the builb while running the engine on carb cleaner but as soon as I quit spraying the engine would quit. Maybe stuck float. Any ideas appreciated?

Second truck, only as far as oiling the cylinders on that one so far. Drain plug on the gas tank is messed up, can't get a wrench on it. Might have to drill and easy-out it.

Link to thread in the M37 forum:
http://www.steelsoldiers.com/m37/52476-bought-two-m37s-today.html

 

[Roller]

Check for fuel line contamination. Sounds like the pickup in the tank is clogged or there is a blockage in the line. This is common in an older vehicle that sits unoperated for a time.

Frank

 

[gonorth]

Roller, that could be part of it but I was able to hook a clear plastic tube to the fuel line at the carb connection and literally suck fuel thru the line and pump. It took some sucking to do it. Do I dare shoot some air thru the pump and line from where the line connects to the carb? Thinking that might unclog anything, at least temporarily.

 

[Roller]

I wouldn't blow air back through the fuel pump, I would disconnect the line feeding the pump and blow back from there, although it seems that you are getting fuel to the pump. I think your fuel pump is not working, the diaphram may have disintegrated.

Frank

 

[Capt.Marion]

Disconnect the line from the tank to the pump at both ends and blow some air through there with your air compressor.

 

[olgraybeard]

1. take thtop off the carb bowl and clean out pull out jets (count turns) and squirt with carb cleaner put after market fuel filter in gas line after clean out drain gas tank and fill with new gas then give it a try

 

[alessandrofurlotti]

M37 Engine Flooding

Hi Guys, thought I'd try to post here in the hopes of getting a reply.

I have a 1953 M37 here, beautiful truck, with a big problem.

It starts up like a dream when cold, but as soon as it warms up, if you turn it off and try to start it up again, the engine immediately floods. It will only start up after an hour or so when everything has settled down.

I initially thought this was a carb problem so sent it off for a refurb but no such luck. Even after the refurb there's the same problem.

Wondering if anyone had any ideas/had the same problem?

Thanks

Sandro

 

[rosco]

On these old vehicles, often with much deferred maintenance, all the components need to be re-worked. Grease dries, stuff gets grimed up.

I always thought the standard fuel pump was problematic, especially the lower vacuum boost part, which will & can start pumping oil. They were built to be re-built. Often they produced too much pressure and a pressure regulator that keep the pressure to the carb below about 3 psi, will solve some of the problems. I use mine daily on the ranch, and simply bypass the fuel pump, and use a 24 v electric, keyed to the ignition. The stock distributer needs to be looked over too. Check the shaft bushing is not too worn, and the advance weights, to see that they move freely. The truck is 50+ years old - bring the "TLC" factor current, before expecting them to be dependable. They typically take far more maintenance then vehicles today!

 

[alessandrofurlotti]

Which pump

Hi Rosco, thanks for the reply.

If I were to replace the mech fuel pump with an electric one, which would you recommend? Which did you use, since from what you said it seems to have solved many of the problems?

Sandro