Injector pump problem

[Arecibo]

For you all who actually know tractors (unlike me). I have a 2014 Nortrac XT 25 with the Koyker FEL, purchased new in 2014. It has been a good tractor, though it only has 96 hours on it. I have a one acre property so I just use it for minor things like grading a road or moving dirt. The one problem I have had almost since the beginning was that I have had to add oil to the injector pump every few hours of operation in order to have it show on the pump dipstick (the tractor has the Laidong 3 cylinder engine with the fuel injector pump that has the dipstick). I have probably added just over a quart of oil to the pump over the last 9 years and, stupidly did not think about where that oil was disappearing to. Yesterday I happened to check the engine oil dipstick and noticed that the oil level was up about 2 inches over the top indent (I know what you are thinking, what a dummy), anyway, I pumped the extra oil out and removed about a quart to get the level correct. The engine oil is Rotella T3 15/40 diesel and the oil I had been putting in the injector pump was 30 weight non detergent (that had been recommended somewhere though I have read that other people use the Rotella T3 engine oil or other oils).

So, my questions are, does the pump have a bad seal(s) (kind of obvious I suppose) and can it be repaired or should the pump be replaced. All advice would be greatly appreciated. Thank you.
The tractor is made by Foton Lovol.

 

[Bob Rooks]

The fuel injection pump has a shaft seal. Replacement requires removing the pump and it's drive gear. Pretty straightforward but should be done carefully so as not to disturb the shaft, which could throw the timing off. Be sure to scribe witness marks on the flange and engine block so it goes back in exactly as it came out. Unfortunately there are no factory instructions for this.

You want to use the same oil that you use in the engine.

It should be noted that a lot of fuel injection pumps are pressure lubricated from the engine's lube oil system, which you could do if you desired, and eliminate replacing the seal.

 

[Arecibo]

The fuel injection pump has a shaft seal. Replacement requires removing the pump and it's drive gear. Pretty straightforward but should be done carefully so as not to disturb the shaft, which could throw the timing off. Be sure to scribe witness marks on the flange and engine block so it goes back in exactly as it came out. Unfortunately there are no factory instructions for this.

You want to use the same oil that you use in the engine.

It should be noted that a lot of fuel injection pumps are pressure lubricated from the engine's lube oil system, which you could do if you desired, and eliminate replacing the seal.

Thank you Bob. Are you saying that I do not have to do anything and the pump will still be lubricated by the engine oil or does what you said only apply if the pump is lubricated by the engine oil, how could I determine if my pump is lubed by engine oil.

 

[Bob Rooks]

If your injection pump is lubed from the engine there will be a small hose (or steel line) from the oil gallery on the side of the engine (which contains an orifice) to the injection pump. In this case you must monitor your engine oil more closely to detect any possible fuel dilution. Safe to assume your pump is not pressure lubricated because the level continues to fall.

 

[Arecibo]

If your injection pump is lubed from the engine there will be a small hose (or steel line) from the oil gallery on the side of the engine (which contains an orifice) to the injection pump. In this case you must monitor your engine oil more closely to detect any possible fuel dilution. Safe to assume your pump is not pressure lubricated because the level continues to fall.

Thanks again Bob. I guess it is repair time if I can find the part or parts necessary, and not being an engine mechanic I am not looking forward to this repair.

 

[Bob Rooks]

Thanks again Bob. I guess it is repair time if I can find the part or parts necessary, and not being an engine mechanic I am not looking forward to this repair.

You will likely have to order a new seal by description rather than part number. Easy-peasy if you have a metric caliper. Multiple sources for metric seals, use what works best for you.

Google Search

www.google.com

 

[piper184]

Before tearing the pump apart for a suspicious seal I would want to know more about the situation.

First, use the same engine oil for the pump. That way any leaks that wind up in the crankcase are compatible and do no harm.
Second, check the crankcase oil for fuel dilution. Having an oil analysis is the best way do to that.

You said you pulled about a quart of extra oil out of the crankcase. Have you added a quart of oil to the injection pump since the last engine oil change? If not, you crankcase is probably getting fuel in it. Best to figure this out before removing the pump. It would be a shame to go through all the effort of replacing the seal just to find out it needs to come off for a fuel leak issue.

Have you ever completely changed the pump oil? Probably not at only 96 hours. There are probably several things to do at the 100 hour maintenance window. Now might be a good time to jump in and do them all. You are close enough on hours.

I would want to completely drain the pump and refill. Measure how much it takes. Then you can use this to gauge how fast it is leaking down and how much is going into the crankcase.

If the crankcase oil is just oil, then by all means follow Bob's instructions and just replace the seal. Should be an easy job for a beginner.

Take pictures. Ask questions and please post the solution for others to see.

 

[Arecibo]

Before tearing the pump apart for a suspicious seal I would want to know more about the situation.

First, use the same engine oil for the pump. That way any leaks that wind up in the crankcase are compatible and do no harm.
Second, check the crankcase oil for fuel dilution. Having an oil analysis is the best way do to that.

You said you pulled about a quart of extra oil out of the crankcase. Have you added a quart of oil to the injection pump since the last engine oil change? If not, you crankcase is probably getting fuel in it. Best to figure this out before removing the pump. It would be a shame to go through all the effort of replacing the seal just to find out it needs to come off for a fuel leak issue.

Have you ever completely changed the pump oil? Probably not at only 96 hours. There are probably several things to do at the 100 hour maintenance window. Now might be a good time to jump in and do them all. You are close enough on hours.

I would want to completely drain the pump and refill. Measure how much it takes. Then you can use this to gauge how fast it is leaking down and how much is going into the crankcase.

If the crankcase oil is just oil, then by all means follow Bob's instructions and just replace the seal. Should be an easy job for a beginner.

Take pictures. Ask questions and please post the solution for others to see.

Thanks for the advice Piper. I have actually put a quart of oil in the injector, so the amount I removed is probably correct. The oil did not seem fuel contaminated. I will drain the injector completely and measure the amount I add.

 

[piper184]

Just thought of something else.
There should be a vent on the injector pump. If that is plugged for some reason it could cause a pressure buildup when it warms up. This would force the oil past the seal and into the crankcase.
The seal may or may not be damaged. Look for a vent and make sure it works both ways.

 

[Arecibo]

You will likely have to order a new seal by description rather than part number. Easy-peasy if you have a metric caliper. Multiple sources for metric seals, use what works best for you.

Google Search

www.google.com

Just thought of something else.
There should be a vent on the injector pump. If that is plugged for some reason it could cause a pressure buildup when it warms up. This would force the oil past the seal and into the crankcase.
The seal may or may not be damaged. Look for a vent and make sure it works both ways.

Will do, thanks.

 

[Arecibo]

You will likely have to order a new seal by description rather than part number. Easy-peasy if you have a metric caliper. Multiple sources for metric seals, use what works best for you.

Google Search

www.google.com

Thanks for the seal link Bob.

 

[Paddy]

Just to understand, if the pump in not lubed by engine oil, fuel can't mix with engine oil? If he has an oil reservoir on his pump, can it also be duel lubed by engine oil system?

 

[Bob Rooks]

Just to understand, if the pump in not lubed by engine oil, fuel can't mix with engine oil?

As long as the injection pump shaft seal remains good, and the injection pump/governor oil remains undiluted.

If he has an oil reservoir on his pump, can it also be duel lubed by engine oil system?

I'm not sure what you mean by dual lubed. The injection pump and governor share the same oil sump.

 

[Paddy]

Bob,

The first question I had was relating fuel getting into the engine oil, engine lubrication system. As you know from my previous thread, my pump oil was being diluted by diesel fuel. I recall you speculated the high pressure side was lap fitted and they can leak in to the injector pump oil. But if the shaft seal is also bad, then fuel leaks into the injector oil sump and then leaks past the shaft seal and then into the engine.

 

[Bob Rooks]

Bob,

The first question I had was relating fuel getting into the engine oil, engine lubrication system. As you know from my previous thread, my pump oil was being diluted by diesel fuel. I recall you speculated the high pressure side was lap fitted and they can leak in to the injector pump oil. But if the shaft seal is also bad, then fuel leaks into the injector oil sump and then leaks past the shaft seal and then into the engine.

That is correct. But the small amout of fuel that gets by the barrel and plungers should only be small trace amounts unless they are worn from dirty fuel or corroded from moisture or diesel bugs. Trace amounts would not pose an immediate threat of engine oil dilution, and only show up on oil analysis reports. That's why injection pump oil should be checked/changed frequently for fuel dilution.
I have a ball valve on my tank that I shut off after using the dozer. It keeps fuel from gravitating to the injection pump.