Posted: Sat May 27, 2006 6:56 pm Post subject: Ball Check Valve Question...
On the M-38 fuel / vaccum pump there is a line that goes from the vaccum side to the Bell housing then on to the transfer case. In this line just off the vaccum pump is a ball check valve... Which direction should the ball be aligned in the valve??
Should it be such that the ball is towards the pump or towards the bell housing...
I ask because after replacing a dummy valve (a fitting plugged with solder, but looks like the fitting) I now have oil dripping from the fuel / vaccum pump. It looks like 90 wt oil as it is clear and thick... I is definatly not motor oil.
Any help is greatly appreciated... I may put the dummy valve back in to prevent further oil leaks, I finally got them all fixed and sealed properly when this one popped up...
If I read the diagram right you should be putting crank case pressure on the line that the special fitting goes in. Which is in the mid-section where the crank case pressure is.
And I thought the fitting could only be install one way. That is male pipe end screwed into the 1/18" NPT 90.
That's just the way I see it. I don't know for sure.
Someone please set me straight before I get it all tubed up. _________________ Tropical Veteran
35th Inf. Reg. "CACTI" 4th I.D. VN
Amateur Radio K5XOM
Joined: Apr 04, 2005 Posts: 219 Location: Monticello, NY
Posted: Sun May 28, 2006 4:33 am Post subject:
Hi.
The check valve should be mounted so pressure from the engine side will unseat the ball and pressurize the bellhousing, transmission and transfer case. The check valve should be plumbed to the center of the fuel pump, not any part of the vacuum supply. During normal operation the plug should not be installed in the bottom of the bellhousing since that is the vent for the gear boxes. _________________ Bob W. Monticello, NY. 1952 CJ3A, 1952 M38, 1950 CJV-35/U
That is the way I have it plumbed, maybe I have a bad valve in the vaccum pump causing this... I will go back to te dummy valve for now.
I am understanding that the ball in the valve should be towards the bell housing, to keep the pump from pumping to open air thru the housing... maybe mine is the othr way always open with the ball towards the pump, thus when the engine is running the it is applying pressure towards the bell housing.
See the ball and spring in this valve can be removed and swapped to change direction, depending on the application.
What should one do if you do not have the proper ball fitting? Plug the line with solder or leave the vent line unrestricted? I don't plan on actually fording to the jeep's full potential (submerged), but the jeep will get wet crossing creeks, etc... _________________ Tony Morreale
Franklin, TN
I found what was wrong with my Ball Check valve... it is NO LONGER a valve... the ball, spring and Stop are apparently in the vaccum pump. I took the valve out and the inards of the valve are gone, the only place they could go is into the pump. Vibration must have made it come apart
With it being open like that when the engine cooled off it pulled the oil back to the pump causing a leak or the parts that fell into the pump are causing the leak...
It is minor and so will have to wait till Sunday for a removal of the pump and dismantling to see how bad it is... I have a car show on Tinker AFB, Saturday and so need to be able to drive there.
Tony, I took a fitting I got from ACE and filled it with solder to prevent fluid flow... worked fine until I replaced it with the proper valve...
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It looks like 90 wt oil as it is clear and thick... I is definatly not motor oil.
