Info needed: M38A1 fording valves

[Les Kovacs]

On previous posts I asked for info on the oil burning issue I have had....about a liter of oil for every 300-400 kms....the engine has been rebuilt about 2000 kms ago... no visible blue smoke on start or driving, plugs show no fouling and only minor oil leaks at rear main and front crank seal. I also mentioned that both fording valves (at carb and side valve cover) are open....well, in fact, the top fording valve was actually closed! I decided to clean the valve and upon disassembly, found the valve closed....I cleaned everything and put everything back with the valve open (blew through it to see if it was open).
Question....could this have been one of the issues for the oil burning?

The lower fording valve was taken off a few months ago and cleaned. At that time I just reassembled it and replaced it onto the valve cover/fuel pump.....I have left the lever parallel to the piping assuming that this was the open position but I did not test it.....I do not want to take it off....can anyone send me a picture of the valve in the open position as at this point I am not sure.

Question.....if both valves were actually closed......could this have caused the excessive oil consumption?

Thanks in advance,

lesk

[Lynn Eades]

Les, what kind of vehicle are you talking about, and what exactly is a fording valve?

[Les Kovacs]

Hi Lynn,

M38A1 (CDN2)....Canadian, second batch! Fording valve is to make jeep waterproof.

lesk

[rob love]

Lever inline with the pipe is open. However, it is possible to install the lever 90° out on the ball valve in which case my answer goes out the window.

[Wayne Hingley]

Originally Posted by Les Kovacs

....can anyone send me a picture of the valve in the open position as at this point I am not sure.

Photo as requested... I recommend securing it in the open position with some wire.

[rob love]

If you think about it, the lever is as far away from the cable bracket as possible......the theoretical cable would be pushed all the way in which is the normal position. Pull the cable at the dash and you would pull the lever (s) back 90°.

But as I mentioned, this is all subject to the valves being assembled properly in the first place. I did run across one that had been wired into what should have been the open position, only to actually be in the closed position. I even remember the CFR of that Jeep some 30 odd years later.

[Les Kovacs]

Thanks Rob & Wayne.....and happy holidays!

The upper fording valve (air filter to carb to oil filler)-lever was parallel to piping but it was closed-(no air passing through)-I put the lever parallel to piping and blew into it....it was blocked-rotated lever 90 degrees to piping and blew-it was open-so I left it in the open on reinstallation. Could this have been the cause of the small oil leak at the rear main and front crank seal-engine under positive pressure?

The lower fording valve as with Wayne's picture-the lever on mine is parallel with the piping so I am assuming its open. However, I will disassemble and check as I am now weary due to the upper one being parallel but closed.

Again, the upper one being open for so long may this have caused the minor oil leak at the rear main and crank seal. Also, as both valves will soon be positively left open, will the small oil leaks seal up?

As always,

Thanks,

lesk

[rob love]

If you are checking the lower, also make sure the PCV valve is in the right direction. If it was on backwards, it would be as good as having the valve shut.
Having one valve closed should not cause the oil leak as the pressure would still exhaust out the other open one. But if both were closed, it would certainly be the cause of oil leaks.

[Lynn Eades]

Ken, I've never met one of these Jeeps, but as no one has directly answered your question and following on from what Rob has said, Then I'd say: Yes, The excessive crank case pressure could very well increase oil consumption.
Changing a negative pressure in the crankcase to a positive pressure would likely be enough.

[Les Kovacs]

Rob....as per your suggestion of checking the PCV valve...would you have a picture or diagram as to what direction the check valve is supposed to be facing in the PCV valve? Also, can I check this by blowing into the end directly coming out of the valve cover.....if air does not pass through I assume that...1. the fording valve lever is closed or 2- the PCV check valve is stuck/backwards? I am assuming that what I am looking for is blown air to pass all the way through the valve piping & PCV valve and into the fuel pump?

Regards to all that responded to this post.

lesk

[rob love]

You should have a clear path for the vapours to leave the engine side pan. The PCV valve will prevent a backfire from feeding back into the engine and blowing the oil pan off.

If you don't have a clear path, then as you mentioned either the fording valve is closed, the PCV valve is backwards, or the PCV valve is gummed closed. The PCV valve should be cleaned once in a while, otherwise any buildup could result in it not closing fully and allowing a backfire to feed into the bottom half of the engine.

[Les Kovacs]

Thanks Rob....Happy New Year!

lesk