2640 JD

petehall · Mar 15, 2017

A friend has diesel fuel getting into his motor oil in large amounts ??
What could the problem be????

JD Seller · Mar 15, 2017

The injection pump cup seals on the pump drive shaft are bad. That tractor used the Roosamaster injection pump. They are not too hard to replace.

Take the side plate off the injection pump. Line up the timing marks. Take all the injector lines and fuel lines off. Then remove the injection pump mounting bolts. Slide the injection pump towards the rear of the tractor. The drive shaft will slide out of the injection pump.

In the picture you see the two cup seals back to back. They keep the diesel fuel inside the injection pump. You just CAREFULLY stretch new ones back on the shaft. Try not to over stretch them. Then when you slide the pump back on the shaft you have to guide the one seal in cup face first. You have to keep it from turning wrong side out. I have found silicone spray lube works good to help the cup seal slide into place. Once you have the front seal sliding in the rear one usually just goes right in as it is sliding with the cup face towards the back. Then just line the timing marks back up and tighten the pump mounting bolts. Reinstall your lines. Then bleed to injection pump and your good to go.

MikeJM · Mar 15, 2017

Lift pump or injection pump or both, start with the lift pump first to eliminate that.

Dieseltech · Mar 15, 2017

As mentioned, most likely the supply pump and/or the injection pump. Best to start with the supply pump first, that may correct the leak. If not then the injection pump is most likely the culprit. There's a brass tube inside the pump housing that will get grooves cut into it over time where the seals ride. In most cases the REASON the seals begin to leak is due to higher than normal injection pump housing pressure, due to a failing weight retainer as the small bits over time restrict the return system. If that's the case the pump needs serviced, before the retainer pins get sheared off causing major damage. Most pumps have enough age and wear the brass pilot tube should be replaced also.

2640 JD

petehall

Member

JD Seller

Well-known Member

MikeJM

Member

Dieseltech

Well-known Member

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