The Fordson Tractor Pages Forum

When my E1ADKN petrol/tvo Major starts from cold, oil pressure is around 40psi, but after about 30 minutes running it drops back to an indicated zero or thereabouts. Despite this, she pulls like a train with no rattles or other signs of distress.

I suspect a faulty guage or pipe problem, if only because I would have expected a conrod to come out and shake my hand before now if there was an engine problem. Has anyone come across this before? Could it be a blocked pipe? Or maybe an airlock that needs to be bled out (I'm not sure if the pipe needs to be full of oil and I can't find anything in the Workshop Manual to help).

I see new repro guages are now available, with a 5"/125mm stub pipe out the back that has to be joined to the pipe connecting it to the block, so replacement is possible, but the pipe question remains.

Any advice will be much appreciated.

Henrietta ran for many years like that and it was not until I overhauled the engine that the oil pressure came up. I would doubt whether you have any problem with gauge or pipe.

Two things about that tractor engine, You need a fairly heavy oil, 15/40W is not really good enough, it would be better with a straight 40W or even 50W. I used to use 15/40W in Henrietta but last year I discovere that Halfords do an oil for older engines. This has improved her oil pressure and I now use it in Dotty and Harriet.

The engine oil in your Major will get heavily diluted with paraffin if she is used on light work. It will need changing at very regular intervals. I did not change Henrietta after a period of light trailer work then I put her into a short bit of hard work and knocked out a big end.

The engine must run very hot all the time. The exhaust should glow red at night along with the manifold and you should be able to see about 6" of flame from the top of the pipe. Then you know she is running well.

Thanks a lot for the info Brian - very helpful, as always. I, too, have tried different oils -

I tried Castrol SAE 50, but start up produced some worrying noises and I wondered if perhaps the oil pump was struggling to move the thicker stuff when it was cold. Pressure when it was hot dropped back pretty much the same, after 30 mins or so.

I tried Castrol GTX and this was fine and pressure stayed up longer - perhaps for about an hour, but then dropped back again. Only stopped using it when I read somewhere that GTX might carry a bit too much detergent than is good for an old engine.

I'm currently running on Castrol SAE 40 - I saw a 'classic' oil in Halfords and planned to use it at the next change, but I think the one I saw was a multigrade - I'll have to go online and see if they do a 'straight' SAE 40 version, which I guess is what you are using. The can said the oil also carries a seal conditioner and that made me think it would also be good for the gearbox/back axle as I have the usual leakage between the two. If anyone has any experience with this, I'd be pleased to know.

Thanks again, Brian.