Oil leak at fuel pump

[Lynn Eades]

Of couse your system will be slightly different, so move with care.
Tony Smith is right, photos are better than me telling you.

The info regarding adjusting the valve is referring to ports marked the same as Michaels picture of the valve.

David that "breather' you have arrowed is the grease cup for the thrust bearing.

[horsa]

Thanks Lynn, something new for me to research as I have a hex bolt there for some reason. I probably filled the hole during restoration and promptly forgot about it....


Per Lynn's post below....I do remember fitting a sealed bearing so might have eliminated the grease fitting at that time. Thanks

[Lynn Eades]

There were two types of thrust bearings used, but a modern sealed bearing is probably the best. Then we are not inclined to over grease it, and end up with a stuffed clutch because it has grease in it.

[ajmac]

Great info there chaps, so if Andrews PRV is set at 10psi like the manual suggests, but isn't being used to regulate hot and cooled oil mixing as the original design intended, rather just dumping oil over 10psi back to the sump via the filler then there is a problem.

[andrew honychurch]

Fantastic, what a great wealth of knowledge there is out there. Its as good as having you all here inthe workshop with me, but without out me having to crack the tinnies!

No seriously , thanks a lot all of you, there are some really interesting points here.

I have to assume, maybe wrongly, that what I have is how it is meant to be on my vehicle. I cannot id the oil pump fitted to mine, as I have not an indpeth knowledge of what the other types look like, but as my vehicle is June 1944 and has the thermostatically controlled valves in the oil coolers , it seems that there may have been a change to the way the system is plumbed.

At present , my best guess is that I have the correct set up but a blocked or restricted cooler. Remember, that during my first tests and run to War and Peace the cooler was getting hot, i.e working. Now it is not. I reckon therefore that the restricition is opening the relief valve and that is whay we are seeing too much oil being fed back through the filler neck.

Much as I didnt want to do it, as its a pain in the arse job, it seems I will need to pull the cooler off and clean it once more with solvent to try to get it flowing ..

Given the low pressures on these engines, its seems logical that it would not need much of a restriction in the cooler or lines to cause the PCV to operate?

David, on the oil greaser, did you have a flexible pipe inside leading from this to the thrust bearing? If not, dont fit the greaser or it will dump into the bellhousing!!

I hope to report back later chaps, many thanks Andrew

[ajmac]

Good luck investigating.
Attached is a little single line sketch of the various Flathead V8 oil system layouts. Yours is the third one down, at least on the face of it!

On a well designed modern oil sytem you would have a PSV (Pressure Safety Valve) around the pump to protect from dead heading, this would be the highest pressure setting in the system and shouldn't lift in normal operations. After the pump you would have the main PCV (Pressure Control Valve) for the system and after that the TCV (Temperature Control Valve) directing some oil to the cooler and mixing it with hot oil to maintain a set temperature before sending it on to the oil filter and the things you want to lubricate! You would monitor the line pressure after the filter just before the things you want to lubricate.
In an automotive application it would be quite acceptable to combine the PSV and PCV into one PCV as part of the pump.

PS. The rear main is fed directly from the pump discharge before it ever gets to the top of the bell housing, thats what makes fitting a full flow oil filter almost impossible.

[andrew honychurch]

ok, so I have had time to investigate and this is what I have discovered.

1. The outlet pressure from the cracnkase/bellhousing is the nearest the left hand side of the engine, and feeds directly into my PRV.

2. I have established that I am getting flow back to the other elbow.

3. As the engine heats up, which takes a long while as I dont have thermostats in the cylinder heads, the oil cooler takes more of the flow and the relief flow to the filler tube slightly reduces. I hope and suspect that as the engine gets really hot there is less flow to this tube and more to the cooler.

4. I dont know quite why my system has been created, as its not in the TM but I think it probably works. MY suspicion is there is a design fault that means that the fuel pump fills up and if you operate on rough ground at speed as I was doing, it will spill out some of this oil

5. I can try to make a gasket for the fuel pump aperture which is better at resisting this oil flow.

6.I have oil pressure, I have oil cooling, and I have an engine that works, so until I can find a Chilwell ( or FORD USA ) mod sheet I think I am going to leave well along and try to avoid oil spillage by physical means.

Thank you all for the help on this, and if the problem continues I will post again, but until I have got the engine really up to temperature I cannot say for sure whether this relief valve flow will cease.

thanks

[andrew honychurch]

I am still struggling to work out why the British army modified the PRV set up as per mine on the above photograph. Of course I have no information on it as I have the original TM s . I have seen one other T16 with this set up, again ex British Army. I don't suppose anyone has any post war British manuals for T16's they could check in?