Lehman 120 Injector Punp Drain

[psneeld]

I know it's been discussed.

I searched and never found the one or two threads I remember and tried Google too.

If anyone posted or remembers the threads discussing the drain plug on the injector pump of a Lehman 120 and can point me in the right direction thank you.

Mine stripped yesterday even with a slightly less than prescribed torque.

Maybe log ago damage. It snugs up by hand...but I am not satisfied that it will stay.

Anyone do this repair on engine?

Thinking just overdrill, tap and go to 3/8 24 bolt instead of the 5/16 24 bolt. Maybe use an o ring this time to lessen the temptation for a slightly harder turn for snugness.

Ideas or pointers to a thread that can help?

Thought helicoil but seems overkill for a sump drain.

 

[Xsbank]

The challenge is to keep swarf out of the pump housing. A successful repair is to use Weld Bond and a valve.

 

[psneeld]

Thanks...but success with glue in an oil rich environment when on the road just doesn't feel right to me.

Anyone drill and tap?

Also,if I remove the raw water pump, the 1 inch johnson....is there a oil removal issue into the gear housing or is it all drained out of there after shutdown?

 

[Larry H]

I have removed the raw water pump. No oil comes out. No need to drain the engine oil.

 

[Capt. Jon]

"Thought helicoil but seems overkill for a sump drain."

No worse than drilling oversized and tapping!

 

[kchace]

This sort of repair is done all the time. Apply copious amounts of grease to the drill bit and drill with the bit spinning very very slowly, remove, clean and regrease the drill bit VERY often. Repeat with the tap. If you go slowly and clean often, the grease will capture almost all of the cuttings. I think I would then flush a fair bit of oil through there to help push any remaining bits out. You're also aided by the fact that you will be drilling iron at the bottom of the reservoir which due to its weight will tend to keep it there.

Ken

 

[waddenkruiser]

We had the same problem on our old boat with the screw to control the oil level.
A mechanic solved it by inserting a helicoil. Don't know how he drilled it ...


best regards / med venlig hilsen
wadden

 

[meridian]

I'm under the impression the housing is aluminum.

 

[Larry H]

The injector pump housing is aluminum and not very thick.

 

[psneeld]

The housing is aluminum so I think I'll try a 3/8 24 tap and bolt.

Drilling from the bottom should not present a debris problem. A little grease, probe the hole and flush once should do it.

Thanks so far...still listening...hoping for magic potions or miracles though...

 

[alormaria]

Can you wrap the plug with plumber's tape and snug it up enough to stop leaking? Put a "Spanish Windlass" around it to hold it in place when you are not looking at it.

I've run my fill hole plug like this for years.

 

[jleonard]

I haven't drilled/tapped the pump, but I have drilled & tapped other engines for various reasons.
As mentioned above, grease the drill and the tap.
Also if you have a helper consider SLIGHT air pressure to the pump via the fill hole to make sure the chips exit the drain hole. Maybe something like 2 psi. You could use a dinghy foot pump. Or rig a tube and use lung pressure.
You could also vacuum the drain afterward.
Of course leave the drain open after all this a d let some oil flow thru to make sure the chips are evacuated.


Oh and use a bottoming tap (or grind off the point).

 

[Shoalwaters]

Your plan of the 3/8 x 24 bolt is the way to go. O-ring sounds nice, but tends to squeeze out from beneath bolt-head unless you can machine a groove for it. Maybe a fiber washer?

Agreed that a Helicoil is overkill and you still have to increase the hole diameter.

Drilling/opening-up holes in aluminium casings is fraught with peril - mainly that the drill bit tends to grab and chew up the workpiece. Step-drills can work well here. How much room do you have inside the pump body? If not much, then maybe a cheap HF s/drill and grind off the unwanted part?

 

[psneeld]

I haven't drilled/tapped the pump, but I have drilled & tapped other engines for various reasons.
As mentioned above, grease the drill and the tap.
Also if you have a helper consider SLIGHT air pressure to the pump via the fill hole to make sure the chips exit the drain hole. Maybe something like 2 psi. You could use a dinghy foot pump. Or rig a tube and use lung pressure.
You could also vacuum the drain afterward.
Of course leave the drain open after all this a d let some oil flow thru to make sure the chips are evacuated.

Oh and use a bottoming tap (or grind off the point).

thanks!

 

[psneeld]

Your plan of the 3/8 x 24 bolt is the way to go. O-ring sounds nice, but tends to squeeze out from beneath bolt-head unless you can machine a groove for it. Maybe a fiber washer?

Agreed that a Helicoil is overkill and you still have to increase the hole diameter.

Drilling/opening-up holes in aluminium casings is fraught with peril - mainly that the drill bit tends to grab and chew up the workpiece. Step-drills can work well here. How much room do you have inside the pump body? If not much, then maybe a cheap HF s/drill and grind off the unwanted part?

good points and tips!

 

[meridian]

I believe you need to use a bottoming tap as there is a cam lobe on the other side of the hole. Use something to see how much clearance you will have. Flush well.

 

[psneeld]

Probed with a paper clip...nothing remotely close by (at least an inch or more)... The overflow hole maybe but I think the sump is deeper and nothing nearby.

The hole is surrounded by an extension of the housing...I figure I only need 3 or so threads against a compressible washer or o-ring. It is only a drain like on an oil pan so after years of dealing with being careful yet not having problems with stamped metal oil pans...this should offer some cushion for less than machine shop performance.

Will be careful in all aspects but as usual...it might go easy and well or horribly wrong ....as many field repairs can go either way in a heartbeat..

Thanks to all...

 

[jleonard]

You may also want to consider tapping it to a 1/8 NPT and use a pipe plug.
The tap drill size is almost the same as 3/8-24.
If you have clearance between the two pumps you could use a street elbow & make draining real easy.
Just a thought.

 

[kolive]

I had the same issue and tapped mine to install a brass valve to drain the oil. Works great and does not leak. PM and I will send a photo. I cannot find my resizing software to post one.

 

[kolive]

The thread I posted to with the photo is titled, Simms pump drain plug.
http://www.trawlerforum.com/forums/s6/simms-pump-drain-plug-15437.html

It has the photo of my tapping and valve install

 

[kchace]

I would not use an oring for the reason already cited. Without a machined groove that the oring resides in, you will be tightening the oring directly. That means you can't tighten the bolt very much without risk of completely trashing the oring which will of course defeat the purpose. On the other side, a bolt that isn't very tight is not very secure. I would also suggest going with a fiber washer.

The idea of using a tapered pipe thread is interesting. If you were sure you had enough "meat" around the hole it could solve a couple of problems at once.

Ken

 

[Xsbank]

Use one of these: no, don't panic, just the small brass valve. Costs about $3.

 

[Marin]

In addition to all the above suggestions this has been a topic discussed over many years on the Grand Banks Owners forum Grand Banks Owner's Resources. I believe you have to join to search the archives of that forum, but there have been many, many discussions of the best ways to solve this problem and solutions from people who work/worked with these engines for a living.

 

[psneeld]

I would not use an oring for the reason already cited. Without a machined groove that the oring resides in, you will be tightening the oring directly. That means you can't tighten the bolt very much without risk of completely trashing the oring which will of course defeat the purpose. On the other side, a bolt that isn't very tight is not very secure. I would also suggest going with a fiber washer.

The idea of using a tapered pipe thread is interesting. If you were sure you had enough "meat" around the hole it could solve a couple of problems at once.

Ken

I bought a couple of thick neoprene washers so that is solved.

Because there is no pressure in the sump and just the worry about loosening, I feel snugged against a compressible washer is satisfactory.

I think using a tapered and force required to seal set up could be a mistake in this aluminum case.

A couple threads and a decent washer should be all it takes.

 

[jleonard]

I think using a tapered and force required to seal set up could be a mistake in this aluminum case.
.

Use Loctite (or equiv) and it doesn't have to be tightened as much as you think. Plus, it only has to be tightened once if you can fit an elbow and /or drain valve.

However your plan sounds fine as well. I think there are several ways to solve this problem.

 

[psneeld]

Use Loctite (or equiv) and it doesn't have to be tightened as much as you think. Plus, it only has to be tightened once if you can fit an elbow and /or drain valve.

However your plan sounds fine as well. I think there are several ways to solve this problem.

True....

Being on the road limits me to a point.

If the 3/8 bolt works and there looks like there is more meat there, maybe next summer when I'm stationary for months with all sorts of support around...I may play with it. But I only have to drain it 2 more times this trip so I'll be satisfies if I could even just get it to seal well enough that a few drops an hour wouldn't bug me too much.

 

[psneeld]

Day one of running...7 hours and no leaks.

Drilled and tapped 5/16 hole for 3/8 bolt Tapping did not go well on engine because of awkward angle and seemingly very soft aluminum housing.

Did manage to get a solid 4 threads or so in housing started....bolt was cut to size but may have been a tad too long as snugging up on a single neoprene washer was not fun thinking stipping again. After over night set.... no leaks, drained and filled after swabbing for no errant shavings, added second washer and ran today.

In a couple three years, if all stays the same...I will get the pump overhauled and that hole tapped better with possible an "l" added to help in draining or a valve.

If another field repair is necessary this trip, Jay Leonards suggestion of pipe tapping with plug and drain assembly may happen.

 

[jleonard]

Well, good on you, at least you got it done. Not much room to work with that's for sure.

 

[psneeld]

Day 2 and not a drop leaking or loosening of the bolt. So far, so good.

Hilton Head is cold and windy but I will bet better than South Jersey!

 

[Xsbank]

There you go. Solve the problem before it becomes a problem.