Ford Lehman 120 injector pump oil

Hi all, just did engine and oil injector pump oil changes... the engine oil looked "normal" and the injector pump oil was brown, very gross. Maybe it hadn't been changed in years or maybe there is another problem. Since both engines were the same I assumed there isn't a problem except the previous owners. I wouldn't have even known to change it if I didn't watch a bunch of YouTube videos about the FL120 before working on it.

Anyway I have to wonder with modern oil technology, if it would be better (or at least acceptable) to use full synthetic oil on the injector pump and run it longer (as long as the engine oil? Engine #2's injector pump in difficult and messy to change.

Does anyone install a valve and barb to the bottom of the pump to make changes easier and less messy?

My understanding is that injector pump oil on the FL120 is susceptible to fuel contamination given it’s in the injector pump and it’s such a small amount of oil.

Therefore the FL recommended change frequency.

Agree on a finding a better way to drain. My starboard engine requires a ’blind’ change and it’s pretty damn messy. I’ve found using a freezer sized zip lock bag works well.

Bob Smith recommended 50 hour changes until you found that the particular engine could go a bit longer without fuel dillution. He said that he would not go longer than 100 hours in any case.

Attached oil change pump to installed valve and hose.

What are we looking at in those photos? Is that a quick-disconnect? Hard to tell in that bottom photo...

Great idea... I've always used a small ziplock and it was still about 50/50 on spilling.

Not a quick connect. Ran a tap inside the drain plug port. ( 1/8 NPT ) Added a ball valve, ended with a length of capped hose. Attached oil change system to that.

THAT makes sense thank you.

Be careful when you screw in to the pump. The rotating cams are right next to the drain. The pump holds 14 oz of oil. Drain, add 14 oz, no need to check overflow plug

on mine theres a little room in the sump where the drain plug is.

mine stripped and while on the road the best I could do is tap a 3/8 bolt for a drain plug.

to make sure I didnt hit anything I measured and IIRC there was enough room for a a 1/2 inch bolt with room to spare.

Impressive. Mine has leaked just a little for the whole time I’ve owned the boat. Afraid to tap it out for fear of a metal shard getting in the pump works. Am I being paranoid? Did you flush the pump after you tapped it?

Yes, flushed with lube oil.....a lot. Been running this way for about 5 years now.

SeaMoose said:

Impressive. Mine has leaked just a little for the whole time I’ve owned the boat. Afraid to tap it out for fear of a metal shard getting in the pump works. Am I being paranoid? Did you flush the pump after you tapped it?

Click to expand...

Don't remember for sure, maybe once with diesel diluted oil (the stuff I just drained out plus diesel), there is no circulation in the pump, only splash lubrication. So I wasn't too concerned, as the tapping was upward and not a lot of removed material.

Just used a Q-tip to check for shards...none as I was careful.

The biggest PIA is keeping good pressure and angle if the pump is installed snd you have the new water pump.

Have maybe 1500 hrs on the engine since the tap and bolt went in.

I go 75 hours on mine and so far I drain out the correct amount and it doesn't smell like diesel.
I bought all the parts to add a elbow and shut off but haven't installed them cause I figured out how to drain the pump with no spill.
Only took 5 seasons to figure it out lol