Oil leak at fuel pump

[andrew honychurch]

hey Lynn, some great ideas here. intestingly I did notice that the oil cooler was not getting as warm as previouly. Also noted that the engine oil pressure was getting lower when warm. So maybe there is a blockage in the cooler which has caused the oil to get very warm and be redirected through the return valve. This valve exits , as I said, back into the oil filler tube just above the fuel pump, so maybe its part of the problem. The oil relief valve is in a large brass housing which has been soldered shut. I would have to brake this to take a look and there are no instruction in the T16 manual on setting this up. There is a thermost in the oil cooler circuit which could be failed closed but I think it would still allow flow if it has.

By the PCV valve, do you mean the crankcase breather valve as on a Jeep? If so, yes it does have one of these and I have not checked to see whether it is working, having never looked at one, I assume it can be disassembled? Any instructions on how to check it if indeed this is what you are referring to?

[Lynn Eades]

Yes the pcv valve can be unscrewed. It has a piston (valve) and a spring in it. back then , there were all the same. Note the arrow on the body showing flow direction.
The cooler bypass cap is soldered on. underneath is a screw plug that loads the spring against the ball. this is adjustable.

[andrew honychurch]

I am going to check the PCV first thing this morning. I am a bit reluctant to disturb the oil relief valve, but of course I can check whether this is allowing oil back down the filler tube by looking down the filler tube itself when the engine is running. Will report back. thank

[andrew honychurch]

ok, pulled the PCV and cleaned it not really a problem.

However the oil is flowing continually out of the relief valve into the tube directly above the fuel pump. Hence the problem. Broke the seal on the relief valve and checked it , all good. Turned it two extra turns, which stopped the flow but put the engine oil pressure up to 80 lbs!!!! Broke for lunch and a think. Back on it tommorrow. Maybe the oil cooler is plumbed incorrectly and restricting the flow??/

Edit; there are two fleible pipe that then join onto the steel pipes upto the cooler. If I was half asleep when I assembled it I may have crossed these, but I would think I have checked this was correct at the time. More confusing is the T16 manual which shows the relief valve on the side of the crankcase opposite to mine. In other words, it may be that good old British Army have assembled my engine with the relief valve on the return pipe not the outlet pipe.....Not sure what effect this would have until I can sit down and think about it. so to be clear, my valve assembly is on the pipe on the clutch housing/crankcase nearest the outside of the engine, whereas in the book it appears to be on the union nearest the middle of the engine......Would it matter?? Must do surely

[horsa]

Post some photos showing how you have the lines routed Andrew. It'll make it easy for us to understand what you have going on.

[andrew honychurch]

ok, so here goes, fist the photos then the explanation





in the top photo this is the set up as the vehicle came from the British Army, as far as I know. I have not altered it and the soldered seal on the pressure relief valve was stamped with an inspectors mark. It would appear to me, that the British, or a later Ford modification, has directed the oil relief flow to the point above the fuel pump as you can see in the photo. It is this oil flow, that I believe is finding its way into the fuel pump and flowing out of the petrol relief hole.

The set up as seen in the photo from the TM is quite different. It would appear that the relief valve is on the other side of the two pipes to mine. In other words either the pick up pipe has been changed on my engine, about 12 months later than the date of the TM, or it has been muddled by British Army when they made this mod.

So in the TM photo, it would appear that the pipe nearest in the photo is the return to the engine and the outlet pipe to the oil cooler has the oil pressure gauge and the relief valve attached to it. I assume if there is a restriction in this circuit it returns through the brass interconnection back to the return into the crankcase.

On my engine , you will see that my pressure gauge and relief valve are on the other pipe and the relief has been redirected to the oil filler pipe.

It may well be that I have followed the schematic in the TM ( another diagram not illustrated here) and connected the pipes on the flexible section of the oil cooler lines the wrong way around. I can check this today, but it still does not explain why these pipes are completely different from the set up in the TM. Go figure, and if you can work it out, please let me know.

Meanwhile, I plan at some stage to remove both pipes and check which way the oil flows from my engine left or right pipe then I can connect the cooler pipes the right way around for sure.

[horsa]

Attached a shot of my oil cooler lines even though its a different setup. Yours appears to have a second breather on the driver side of the rear engine. I've got that part connected to the top of my differential and don't have another breather on the engine other than the one where the oil enters the engine at the fuel pump where you are having the leak.

From your routing, the by-pass is open and sending the oil to the upper line. It's leaking is probably related to either the engine having too much internal pressure or air is coming in from the second breather and exiting from the higher original factory one and causing issues with the oil trying to flow inward against it.

Not real sure what the purpose of the alternate oil route would be since I've never seen that on another vehicle so far. If it was providing essential oil, they wouldn't have made it only functional when the valve was in by-pass mode.

Can you open the lines up front and confirm that oil will flow from the oil cooler lines? Or do you have the oil cooler shut off by manual lever if still installed? I don't have the levers on mine so can't turn them off if I wanted to.