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New member that knows absolutely nothing about my 1951 M38
Posted: Tue Sep 21, 2010 7:39 am
by Jake266
Hi all. This is my first post here as a relatively new owner of a 1951 M38. I purchased it about a year or so ago and other than driving it around the subdivision have not been able to do much with it. This spring #4 cylinder lost all compression so it's been at the mechanics all summer being rebuilt. During this time I have started to learn about my M38 as I have absolutely NO knowledge of engines, this vehicle, etc. It is already painted and marked from the previous owner so no off-roading in this one! I plan to mainly use it for "Sunday" drives with my wife and maybe some local parades once I learn the ins & outs of having a semi show vehicle.
Anyway, my first question: In looking at the TM describing the layout and functions of everything on the dash I cannot seem to find anything that refers to a black knob to the left of the steering wheel. Can anyone tell me what this is for?
I'd post a pic but have not located instruction on how to yet, give me time.
Thanks and I look forward to learning a lot from all the experienced people out there.
Posted: Tue Sep 21, 2010 8:09 am
by ECVJeeps
From your brief description it sounds like the cold weather primer system.
The primer pumps gas into the intake manifold for starting a vehicle in cold weather.
This would not be required in the warmer climates and was installed in vehicles
that would be used in a colder climate.
Most M38CDN jeeps had the primer installed.
Posted: Tue Sep 21, 2010 8:26 am
by doctorflatfender
I dont have a clue on the black knob, but, I just figured out how to post picks on here, go to navigation, FAQ, it will talk you right through it using mypicgallery.com, it was easy, even for me.
Posted: Tue Sep 21, 2010 8:40 am
by skyjeep50
Congratulations on your first MV and welcome to the hobby! I would suggest clicking on "Downloads" on the main page of this website and then the "M38 M38A1" section and read through all the TM's that pertain to your jeep starting with TM9-8012. You can download them and print them out if you wish. It will give you an idea of what is needed to maintain your jeep. Then, as your familiarity grows, you can tackle some minor repairs or upgrades and properly keep your vehicle greased and oiled. Getting dirty, taking stuff apart and putting it back together, cleaning, derusting, painting, ordering parts and having little boxes arrive in the mail and getting frustrated at times is all part of the hobby. Have fun!

Posted: Tue Sep 21, 2010 8:52 am
by wesk
that's it!!
Posted: Tue Sep 21, 2010 9:18 am
by Jake266
Cold weather primer. Now to figure out where it connects once I get back to the mechanic later on today. He might already have it connected, I don't know.
I've already download and started reading all the information and am learning a lot when time allows.
Thanks to all for the replies and I'll try to post a couple pics from my file.
As to waiting for the little boxes to arrive, well, let's just say I try to intercept them before my wife sees them!
Posted: Tue Sep 21, 2010 9:39 am
by ECVJeeps
The small brass line goes through the firewall and connects to a brass fitting on the firewall side of the intake manifold.
The larger brass line goes to the fuel tank.
It is a very simple system and quite straight forward.
Congratulations on your new toy.
Posted: Tue Sep 21, 2010 10:16 am
by wesk
Posted: Tue Sep 21, 2010 4:46 pm
by Cacti_Ken
Since we are talking primer pumps, is the packing on the plundgeran o'ring?
Posted: Tue Sep 21, 2010 10:03 pm
by wesk
On real old units they are leather cups and packings.
The primer I have they are square cut and appear to be fabric reinforced rubber.

Posted: Tue Sep 21, 2010 10:34 pm
by Cacti_Ken
thanks, nice picture. I don't know but since I have had mine in for 3 years now. The past two years when I pull the plunger out and and push it back in, there is not any suction or pressure. I do it rapidly to try and get some suction, but doesn't seem to get any. You can tell when there is suction because you can feel the difference, as well as when there is pressure when pushing in. BUt I guess the gasoline has dried the packing.
Guess i'll just unscrew it and see what's going on there.
Posted: Tue Sep 21, 2010 11:11 pm
by wesk
A little coating of 3in1 oil on the cups and packings and the inside of the tube will get her working again. If the oil doesn't do the trick then the two small steel balls are sticking which means pull her out of the dash and open the two ports up and clean with brake cleaner.
Thanks for the help
Posted: Wed Sep 22, 2010 6:55 am
by Jake266
I have copied and printed out the photos and responses from all and am going to bring them with me today. The hoses, radiator, fan and belts are in as is the new fuel level sensor. Today we check the generator and go from there to see what other surprises might be lurking.