Injector pump seals causing fuel contaminated oil?

[chrism0dwk]

Hi All,

Progressing slowly with my 1963 Super Dexta. Having rinsed the gearbox, installed a new main gear lever, and sorted out a badly adjusted clutch (still work on that to do, mind), I turned my attention to the engine.

I checked the engine oil level today, to find that it was right on the 'max' line. When I previously checked, it was about 3/4 of the way up the scale from 'min' to 'max'. This suggests that fuel is somehow getting into the oil (no milkiness from coolant). The chap who sold me the tractor had said that he thought the injector pump seals might have gone, since he knew that the sump filled up with diesel if the tractor was left for long periods with the fuel tap open.

My Dexta has the mechanical injection pump (Simms Minimec, I believe), which apparently has its own oil supply. Therefore, even if the seals had gone, wouldn't the pump contaminate its own oil, rather than the engine oil?

I noticed the paragraph in the owner's manual that talks about the induction primer tap -- however, I'm not quite sure where this should be located? There is a tap (that looks like fig 4 in the manual) just below the fuel filter on the left side of the engine body. It currently has no pipe coming from it. However, there is a small pipe that leads directly from the fuel tap/primer button, over to the right side of the tractor, and then into the air intake manifold. No sign of a tap. Has someone bypassed the tap, I wonder? And could this be the culprit?

Cheers,

Chris

[sky blue]

hi ,the fuel primer tap is screwed into the bottom of the diesel tank left side, if the fuel is getting into
oil via the fuel pump it may be time for fuel pump to be recondition,also the lift pump
which is connected to fuel inj/pump would be wise to replace at same time. if on the other hand you need to replace
the tap that goes into the air intake manifold , this is on the pipe from primer tap to manifold
these are a small brass tap and can be bought from dunlop/ agriline ect ,these were not on all
dextas so it might not of had one in first place,the brass tap into block l/side is for draining the
water from block and would have nothing to do with the oil, hope this helps sky blue

[Brian Cox]

my super dexta 1962 doesn't have a primer type fuel tap, so I would suggest yours will not have one, there is a small primer on the fuel pump which you press in to operate

[chrism0dwk]

Hi Brian,

Yes, my SD does have a primer button on the main fuel tap. According to the owner's handbook, it should also have a tap where the primer fuel pipe enters the inlet manifold, distinct from the main fuel tap. It's this manifold tap I seem to be missing.

Chris

[ol'Blue]

My 63 Super also gets diluted oil in the bottom of the injector pump. I am not in any hurry to overhaul the pump, so I just concentrate the oil once in a while with synthetic 90 wt. I figure it about evens out to 30wt when its all said and done. I know its not the prefered way to run, but I only put about 30 hours a year on my old girl and the pump works so good in every other way.....

before a mowing job or a longer run, I put several ounces of the 90wt in the upper filler hole. then what ever is overfilled will come out the overflow as you run....

I feel like I am in confession.......


dave

[dexta roadless]

I feel like I am in confession.......

I haven't checked my pump for two years