Merc trim pump, oil leaking through motor!

[Alan Power]

Hey Guys,
I have a merc trim pump that's leaking all it's oil out through the motor. Oil is running down the wires that come out of the motor.

Pulled the motor a few weeks ago to take a look and it was full of oil. Cleaned and reassembled, thinking it was oil that got inside from shipping. Put back in the boat and started dripping oil out again!

Any ideas how the oil is getting from the trim pump to inside the motor?

Thanks and Happy New Year,

Alan

[LightNBug]

Depends on which motor/pump you have. Most have a small seal around the armature shaft where it enters the reservoir. The seal may be damaged. The most common cause it that the unit is overfilled with the trim ram/rams extended. When the ram/rams are retracted it forces the excess fluid into the motor. The overfill situation happens many times with a system that is supposed to be vented and is not. The excess is forced into the motor rather than out the vent.

[Alan Power]

Hey LightNBug,

Pump is the oildyne type (square), its not over filled.
The more oil that comes out the less the trim ram lifts. Single ram trim. Eventually, it will need topping up just to trim the motor, not even tilt. Pretty much all the oil will be in the bilge.

What seal arount the armature? I couldn't see one and cant find one on any of my parts diagrams/ manuals! Is it a felt seal?

Thanks, Alan

[LightNBug]

Some had a o ring that fit in a groove at the top the reservoir. Others had a seal that press fit in top of reservoir. Another had seal in motor end cap that was not sold seperately, only complete end cap.

[Alan Power]

Thanks,
Sounds like it's the seal in the motor end cap that's missing. Don't think it would be the reservoir leaking up that far. Any idea what type of seal should be in the end cap? May not be sold by merc seperately but I'm sure theres a similar part out there.

Thanks, Alan

[Alan Power]

Bump, anyone got a picture or a parts diagram that illustrates this part and where it goes?

Thanks, Alan

[LightNBug]

As stated in previous post, these seals were not shown or listed by Merc as serviceable parts. If you have not done so already, remove the pump from the valve body. If you do and still don't see a seal arond the shaft, I would suspect that you have some mis-matched parts. Maybe a pump/valve body that was designed for seal to be in motor, and motor that was designed for seal to be in pump/valve body. Is the pump motor a Eaton or Singer?

[Alan Power]

Ok, thanks, was just looking for some info on what type of seal it is, not sure on Eaton or Singer, it's the square type motor oildyne I believe.

I did take the motor off the pump and motor apart twice and did not find any seal of any description in either place.

Thanks

Alan

[LightNBug]

I didn't say "remove the motor from the pump". I said "remove the pump from the valve body". There are four screws that hold the pump together and two of these four screws hold the pump to the valve body. If you remove just the two holding the pump to the body the pump will not fall apart.

[Sheer Insanity]

It might be the trim motor shaft seal.

[Alan Power]

I didn't say "remove the motor from the pump". I said "remove the pump from the valve body". There are four screws that hold the pump together and two of these four screws hold the pump to the valve body. If you remove just the two holding the pump to the body the pump will not fall apart.

Ah! Ok, sorry boat that! I presumed the seal would be in the motor or on the motor shaft as larryd said.

Alan

[Tom D.]

I've had problems with my trim pump in the past and don't remember if there is a seal on the pump. HOWEVER the motor and pump are 2 separate parts. There SHOULD be a seal/O-ring on the pump shaft and tolerences should be pretty tight here or you would get no preasure out of the pump. The shaft and seal must be pretty shot to wick oil up through the motor and out the wiring. This is just my .02, I my be wrong.

[Alan Power]

That's great, thanks guys.
Will take a look over the next couple of days and see what I can find.

Thanks,

Alan

[Sheer Insanity]

If you need a pump motor I just got on from Outboardparts.com in Sarasota. Cheapest price quick shipping and they sell ARCO Marine. < Good stuff! Free shipping over $200.00.

[Alan Power]

If you need a pump motor I just got on from Outboardparts.com in Sarasota. Cheapest price quick shipping and they sell ARCO Marine. < Good stuff! Free shipping over $200.00.

Thanks larry See how this fairs out!