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I am attempting to put the correct vent lines from the distributor to the wiper tee and from the distributor to the air intake. The manual indicates the vent lines use standard 3/16"od tube with compression fittings. Figure 106 in TM 9-8015-1 shows the two lines above and below the coil. This goes into a bushing that in turn threads into the distributor body. None of my manuals indicate a part number. The problem I am having is that the distributor threads seem to fit the compression fitting threads but the bushing with regular pipe threads is too tight.
The manual indicates one of these fitting is restricted to a 0.040 orifice to control the vacuum. I intended to fill the existing hole in a bushing and then bore the 0.040 hole. I can not find the proper bushing that has the male pipe thread for the distributor and the female part of the bushing threaded for the compression fitting on the vent line.
Is there a part number or has anyone solved this problem in an easier way then I am having. I do not plan to ford with the vehicle but want the fittings tight enough to eliminate any vacuum leak

The G503 website has a link to an article regarding the fording
systems on the CJV-35 and M38. Some information there I
have not seen anywhere else. Not sure of the author.

I bet if you search the web you'll find this article outside of the
G503 site.

Ahh.

It's on the CJ3A pages:
http://www.cj3a.info/sibling/cjv35u/v35vent.html

List of parts down the page.

There's a link on that page to the M38 pages.

Here's a photo:
http://www.cj3a.info/sibling/m38vent/vento.jpg

Sorry I'm piss-a ting this stuff to you but I'm jumping back and
forth on my iPhone.

I think this is the guy you are looking for:
http://www.cj3a.info/sibling/m38vent/vent3.htm

Most of the fittings appear to be standard 1/8" pipe thread.
Maybe you need to chase the female threads in the distributor .

Take care,
Brian

The tube assemblies use inverted flare fittings - NOT compression fittings.

The manual you apparently are missing is the M38A1 parts manual ORD 9 SNL G-758 which shows both and their part numbers. You can download it in PDF here for free:
http://www.willysmjeeps.com/v2/modules. ... tit&lid=87

A bushing when describing fittings refers to a reducer that has both external pipe (male) threads and internal pipe (female) threads.



You need two CONNECTORs, 1/8" P to 3/16" Inverted Flare. They are listed in section 604.1 of your M38A1 Parts Manual on page 148 as ORD # 137404 & ORD STK # H006-0214310.
Here's one source: https://www.doitbest.com/categories/bra ... e-fittings
Inverted Flare Male Connector.
https://www.doitbest.com/categories/bra ... e-fittings
O.D. tube size x Male pipe. 5 per bag and individually flag tagged.
$6.45

Size 1/8" P male to 3/16" Tube inverted flare female.

Item #: 442291
Model #: 54348-0302



The restrictor is not in the distributor body. It is on the driver's side of the engine where you will find the special female "T" that has a 1/4" inverted flare tube connected to it from the vacuum side of the fuel pump and another 1/4" inverted flare tube connected to it running to the wipers. The third female threaded opening in this "T" is for 1/8" P thread and the special CONNECTOR with the .040 restriction threads in there and runs around the back of the engine to the distributor.

This "T" is listed on page 371 of the parts manual. The special CONNECTOR with restrictor is listed on page 87 of the parts manual and is ORD# 7348568, Weatherhead # 100-23123. These are difficult to find so braze or solder the male thread end opening closed and drill it .040.

You can find just about all the above mentioned web site sources for vent system plumbing right here on our downloads page. There are five PDF files you can download there on vent system plumbing:
http://www.willysmjeeps.com/v2/modules. ... oad&cid=47

As a general rule you can almost always find an answer to your question by simply reviewing the several hundred technical photos oin my photo album http://www.willysmjeeps.com/v2/modules. ... _album.php

and find printed data that will answer most of your questions on our downloads page: http://www.willysmjeeps.com/v2/modules. ... =Downloads

I might have a spare fitting with the restriction hole in it.....
Rick

Thanks to all for a great information lesson on vent. I now have a good idea of what to do and have been tracking down the parts.
Brian. I think chasing the threads is the answer
Wes. I only wish I had spent more time in the motor pool

I have a couple more follow-up questions

!. Is the line from the vacuum pump to the wiper "T" 1/4" or 5/16". From the manuals, I get the impression it is 1/4" but don't find the size on diagrams. I got a couple of extra fittings in my bag of parts when I got the car and some are for 5/16"
2. I assume the line from the wiper "T" to the wipers is also the bigger line and the 3/16" takes off for the Distributor thru the special 0.040 fitting.
3. The vent diagrams and narrative tell about the vent on the transfer case. As I do not intend to ford, what do I need to do here? Should this opening be plugged, open, or install a vent line up to atmosphere? Warning on dash speaks about plug in bell housing being removed. Trying to locate this to insure there is not a plug in it.
4. Same question for the master cylinder. Now I have s solid cap on the master cylinder but did get an cap with hole for a fitting. What is recommended here.
5. Wiper fresh air vent at end of passenger side, I assume can just be the open piece of tube that is on the wiper.

Thanks to one and all for sharing your time and expertise. I will upload some photos soon.

Mike D

Mike,
We can get you sorted out.

Wes. I only wish I had spent more time in the motor pool

Mike, I never worked in a motor pool. I have bent wrenches since 1960 but more on aircraft then autos.

Rather then approach your situation one fitting at time why not view the system illustration in your M38A1 parts manual and simply list for us the lines you do not wish to use and we can then make an intelligent suggestion on how to eliminate them without causing engine operating issues. It is best to ID parts using the ORD 9 SNL G-758 which is the M38A1 parts manual I listed above that is available free by downloading it in PDF form to your PC and then print the pages that cover what you are working with and make your parts needs relevant to that figure 03-8 so we can all be on the same page.



Use the Alpha ID for each item you do not wish to use.

Wes
Thanks for your continued help.
I have a copy of ORD 9 SNL G-78
When I got the car and looked into the fording system, I found the hole at the top of the carb was plugged as well as the valve "AA" from the fuel/vacuum pump that leads into the crankcase. The tube to the oil filler / breather was open to the air snorkel. After some reading it seemed this existing setup was partially pressuring the crankcase, possibly resulting in the slight oil leak at the valve cover. I added the relieve tube "E" from top of carb to air intake and connected the valve "AA" with a short piece of hose. Leaked seemed to go away.

Further investigation of the info suggested that the dist/coil needed the vent to properly run and ventilate the dist /coil , so I have started on that. With studying the manuals, I thought the fording valves and control lever on the dash would be so "cool" and allow me to explain a major part of the fording system to observers.
I plan to install the Line, Assy "V" to the wiper T "DD" and the Line Assy"EE" to the distributor. Also the Line Assy "F" from distributor to the air intake.
I will then add the Lines for the Wiper as i move along.
I have obtained the fording valves and have installed the one from the Air Intake to the oil filler /breather. I have not installed the one near the fuel pump. (it looks like a project of threading the pieces in proper order)

I was not intending to install the vent line from the master cylinder Line Assy "FF" and the vent line from the transfer case. I was concerned whether the vent Line Assy "K" from the transfer case was necessary for proper operation in that without it, there may be pressure causing any leaks. I do not know whether this fitting is open or plugged at this point. If this vent line is important for proper functioning, I will indeed work on that installation as well. Again, I don't know what the diameter of that tube should be.
For example I find Line Assy "AA" part number G758-8330238,subgroup 2202 on page 370 but it only indicates 1 tube 21 5/16" long but not the diameter. That tube and one to the wipers does not indicated diameter. I have found that the line assy to the distributor from the wiper "T" thru the "special connector" is 3/16" od but cant determine if the others are 1/4" or 5/16"

I know this is long and seeking a lot of info.

Thanks again.
Mike D

First let's establish what your M38A1 really came with from Willys. Up to serial # MD22359 they came with the vent system plumbing. After that serial they did not have most of the vent system plumbing anymore. Often USMC jeeps had the system added to their jeeps after SN 23359 by using a modification kit.

The military supply manuals take a bit of getting used to. Page 3 of your ORD 9 SNL G-758 Par's 7 & 8 explain what I have shown below about attaching parts of an assembly.

If you look carefully at page 370 you will note the following:



For the rest of the vent system plumbing in section 0304.5 you will find this tubing listed on page 91



Now original tubes were steel with a copper coating but the Army chose to list copper tubing for field repairs. So a factory class resto needs to use copper coated steel whereas a motor pool class can use copper.

After some reading it seemed this existing setup was partially pressuring the crankcase, possibly resulting in the slight oil leak at the valve cover.

On a jeep without the vent system plumbing the culprit for crankcase pressure problems is the PCV valve .

I was not intending to install the vent line from the master cylinder Line Assy "FF" and the vent line from the transfer case. I was concerned whether the vent Line Assy "K" from the transfer case was necessary for proper operation in that without it, there may be pressure causing any leaks. I do not know whether this fitting is open or plugged at this point.

OK, if you replace what is shown at the middle of the fuel pump & L & M with a vent check valve (same as used in both differential housings.), you can then eliminate: T, S, R, Q, L( at transfer), M, L (At Master Cyl), U, FF, G, J, & H. Replace the inv flare to 1/8" P fitting at the air cleaner with an 1/8P plug. You will need to leave the rest of the tubing in place for proper engine operation. If your jeep is early with the fuel tank vent plumbed to the air cleaner I would leave it there since the vented gas oders get fed back into the engine instead of in the cab with you. If you have the later SN without the plumbing you can live with the big vent valve on top of the tank stinking up the cabin or switch to the early system.

As for the vet plumbing at the PCV valve this is how it goes:


Early with vent system installed.


Late PCV without vent valve.

Keep using my M38A1 vent sys photo album: http://www.willysmjeeps.com/v2/modules. ... _album.php

The late A1 fuel vent check valves used on the top of the transfer case & the center port on the fule pump are illustrated below:


The vent check valve is to the right of the bolt item N.


This is the transfer vent check valve. The one above will work here as well.


This vent check valve is specific to the fuel tank.

One final bit of advice: If you elect to install the vent system manual valves make sure you can ID the valve open position of each handle and you should wire them open. If you inadvertently start driving with one or both of these closed you will have rough running issues in a short while and will waste a lot of time looking for a problem with the engine/ignition/fuel system that isn't there!