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RT Firefly 04-23-2015 02:23 PM

OK, in order to minimize spewing MORE oil all over the place what is the oil capacity of the 120 Lehman injection pump please (in ounces)? I fully realize I can fill to overflow of the side orifice (bolt removed) but it would be a lot simpler at this stage just to measure and pour through the fill hole. I'll write the amount down this time so I don't have to keep asking.
Also, anybody have a source for the drain crush washers other than AD? NAPA perhaps?
Thanks in advance.

meridian 04-23-2015 02:29 PM

The capacity is 14 ounces. I also have a small valve on the drain with a tube to drain into a bottle when changing. It also allows me to see if anything settles out.

Duvie 04-23-2015 05:23 PM

Mcmaster Carr?
RTF, I am not sure exactly what the crush washer is that you are looking for but there is a good chance you can get one from Mcmaster Carr. You will have to measure it and order by the size.

meridian 04-23-2015 05:31 PM

Since this is aluminium, I just used an O ring. Too easy to strip out the threads.

RT Firefly 04-23-2015 07:00 PM

Thanks all. Mr. D. The "crush" washer is the one for the injector pump drain. I was hoping to get one locally and not have to order and wait for it's arrival but as Mr. M suggested, I may simply use an o-ring.

Marin 04-23-2015 07:36 PM

1 Attachment(s)
RT--- Here's the thing. Unless your injection pump has been recently overhauled, the chances are great that a wee bit of fuel will be getting past the injection plungers on every stroke. The plungers are lubed by the fuel they pump. The oil in the pump's sump is simply to lubricate the drive mechanism in the lower part of the pump..

As the plungers work, they and the sides of the bores they run in wear. It's the nature of the beast, and is why in this type of jerk-injection system (that's what it's called) fuel lubricity is critical. This is why a lot of FL120 operators including us use a lubricity additive in their fuel.

As the plungers and bores wear, more and more fuel gets past the plungers and goes down in the lube oil below. As this happens the level of lube oil in the sump increases as it is diluted by the fuel.

The reason for the 50 hour oil change on the pump is to ensure that even with a fair amount of fuel getting into the oil, it never gets so diluted that it does a poor job of lubricating the pump drive mechanism.

This is the reason for the breather fitting, usually a banjo bolt, fitting and tube, at the rear end of the pump. It also acts as a means for excess lube oil to escape.

But it can make a mess as you note, and with the engine tilted back, even the "correct" amount of lube oil can cause some to be blown out the breather.

Bob Smith at American diesel gave me his recommendation for dealing with this. First, plug the breather fitting at the rear of the pump by replacing the banjo connector on the plug with a stainless nut with a compressible washer (aluminum or brass) on each side of it. This blocks the breather hole in the hollow banjo bolt.

Of course the pump still needs to "breathe" and this is accomplished by drilling a small hole in the middle of the oil fill screw cap on top of the pump.

I plugged the side breather banjo bolt using a nut and two aluminum washers as instructed by Bob, and when I went to drill the breather holes in the oil fill plugs, found that someone had already done so down in the center of the slot in the head.

So no no more mess. If one has a pump that has a fair amount of fuel leak-by at the plungers so that the pump "makes" a lot of lube oil, the excess can be drained off at the level plug at the forward end of the pump.

Eventually the plunger/bore wear will reach the point where the injection shots themselves are affected and the engine will begin to run poorly. At that point, the pump needs to be overhauled.

When I change the oil in our pumps, after draining the old oil I remove the level plug and fill the pump until oil starts coming out of the level hole. I let any excess oil come out and then I replace the level hole plug.

That's it until I repeat the process 50 hours later. I don't have to measure anything out, and since the side breather hole is now plugged, nothing gets blown out of the pump.

Photo is the side of the pump on our port engine.

RT Firefly 04-23-2015 10:42 PM

Mr. Marin. I'm quite familiar with fuel leakage into the injection pump (IP). A previous Lehman suffered from that malady and when changing the oil, the odor of diesel was VERY evident. The two IP's Im currently dealing with do not seem to suffer that symptom. Drained oil is clean-ish and NO odor of fuel. I do not have the breather overflow (have the fitting but it is blocked) nor a hole in the fill cap. There is a mushroom shaped vent at the top of the IP that allows ventilation but oil/diesel has never come out of there. With reference to your pump, the mushroom vent would be directly above the Simms logo just aft of the throttle control.
Possibly the use of the word "spewing" was too strong in my OP. I simply want to add a pre-measured amount of 30wt oil to the fill orifice without using the level plug "tell-tale". ie: eliminate one more dribble of oil to sop up.

Capt.Bill11 04-23-2015 11:07 PM


Originally Posted by RT Firefly (Post 327293)
Also, anybody have a source for the drain crush washers other than AD? NAPA perhaps?
Thanks in advance.

Try McDonald hardware across from Lester's or Hydraulic Supply behind Lester's. One of the two should have them.

Capt.Bill11 04-23-2015 11:14 PM


Originally Posted by Marin (Post 327375)
This is why a lot of FL120 operators including us use a lubricity additive in their fuel.

What additive do you use?

Marin 04-23-2015 11:47 PM


Originally Posted by Capt.Bill11 (Post 327474)
What additive do you use?

Hammonds LubriBor.

Xsbank 04-24-2015 12:40 AM

Hey RT, if you did not lose the washer, just get your propane torch out and anneal it. It will get work-hardened after a while and you just need to well, anneal it!

There was a very kind gentleman on the Grand Banks site (no silly, not me!) who machined a fitting on his lathe to fit the threads on a Simms pump so you could fit a neat little valve, commonly used on ice makers, so you never have to undo the threads again to drain the oil. He gave it to me. When I get home, I will have a look for it as I don't have a Simms anymore and I will mail it to you (you better only have one engine or one engine will be disappointed).

Xsbank 04-24-2015 12:41 AM

The oil does the lubricating.

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