How screwed am I ??

[nick4634]

I have a deere 6068 in my lobster boat with two hydro pumps running off the pto. One runs the hauler and the other runs the steering. they share a 12 gallon tank. I was cruising in after a day of fishing and noticed my oil pressure gauge was hovering between 15 and 20 lbs when its normally at 35. I shut the engine down and pulled the cover off and the bilge was coated in oil. check the dipstick and the oil level was 3 inches above the full mark. disn't smell like antifreeze, so I check the hydro tank and there was only 6 gallons in it. So I think a seal let go in one of the hydro upmps and filled my engine with hydro oil. Boat gets hauled tomorow and the mechanic will start tearing stuff apart. I'd like to hear some opinions on what to do. engine has 8500 hrs. Boat didn't run hot, no smoking and no loss of power

 

[traditions]

You should be fine.Change the oil and fix the pump.I would guess that the pressure dropped from the oil getting aerated from having to much oil and slapping off the crank.The oil in the bilge came out the crankvent.Hopefully the main seals didn't get damaged.This used to happen with the old GM's with the clutch master drives.I would think as long as you didn't run it that long that way.Another reason for checking the oil every day,to make sure you are not gaining oil or losing it.Hopefully the pump seal just let go and it didn't take days to accumulate the hyd oil in the engine.

 

[nick4634]

It probably ran for up to 16 hrs on the mix of hydro and motor oil. The pump was rebuilt 50 hr ago because it needed a new shaft . I think I'm just going to have the pump fixed change the oil and run the engine till it blows

 

[traditions]

Is it the steering pump? The hauler pump must be clutched.New steering pump around 300.00.A new shaft and labor ,seal kit ,probably half of a new pump.

 

[nick4634]

Yes steering pump. Sorry meant get a new pump. I'm all done dealing with the repair shops around here

 

[Toolate]

How does the hyd fluid make it to the engine crank? Oil cooler or something? Seems like this should be impossible.

 

[nick4634]

engne mounted pto.

 

[Stinkpot]

Friend of mine just had a similar problem. Has a hydraulic power steering pump driven off the transmission. Last week he found over a gallon of reddish oil in the bilge. The hydraulic tank had overflowed and his transmission fluid was below the dipstick.

So in this case, I assume there's a seal in the hydraulic pump that let go and the transmission is forcing fluid into the hydraulic system???

Would that mean that a seal also failed in the transmission, or isn't there one??

Sorry to hijack the thread, but maybe it's a similar problem.

 

[traditions]

I have the same setup on the transmission.I didn't think that there was much pressure where the pump is mounted .That must be what happened.

 

[Toolate]

I am embarrassed to ask again but I thought most hydraulic pumps were belt driven and the hydraulic fluid/reservoir/overflow were totally separate loops from the main. What am I missing?

 

[jwalka51]

John deere marine engines have a gear driven accessory drive that runs off the timing gears in the front of the engine. It literally is a hole in the front side of the engine, right next to the front of the crankshaft that has a spline drive in it. You can run all sorts of things off of it. It is basically a direct gear to gear pto so that you dont need to use belts or run something off of your harmonic balancer. When you use it, the accessory itself has an o-ring on it that seals the hole in the timing gear housing. So the spline is litterally immersed in oil as the engine runs. If you choose not to use it, then there is a cover plate that goes over it with an o-ring that seals it. What can happen is, if you loose the seal in your pump that is being run off this drive, the oil that leaks goes directly into the engine.

Thats the best that I can explain it, if you still do not understand, then you should google a diagram of one

 

[Toolate]

I see- sounds like a remnant of tractor/land use- personally I would rather throw a belt now and then than deal with what the OP is. Probably never happens so its not a big concern but I would rather have a spare belt or 3 and power steering pump onboard than risk this. 3 cent o ring causes 40k in damage if you dont catch it.

Again, I am not familiar with JD so it probably never happens...

 

[Brooksie]

I see- sounds like a remnant of tractor/land use- personally I would rather throw a belt now and then than deal with what the OP is. Probably never happens so its not a big concern but I would rather have a spare belt or 3 and power steering pump onboard than risk this. 3 cent o ring causes 40k in damage if you dont catch it.

...

What he said. I know eliminating V belts is all the rage now. At least a direct drive water pump has drain holes between it and your crankcase but I still like belt driven equipment.

 

[jwalka51]

Actually, the aux drive is only on john deeres marine engines. And as long as you dont loose the seal on the pump, it is a superior way to power your pto accessories. Its not the o-ring thats the problem. The o-ring is what keeps the engine oil from leaking out. The problem occurs when the pump shaft seal goes, then the hydraulic oil goes into the engine.

 

[Brooksie]

Actually, the aux drive is only on john deeres marine engines. And as long as you dont loose the seal on the pump, it is a superior way to power your pto accessories. Its not the o-ring thats the problem. The o-ring is what keeps the engine oil from leaking out. The problem occurs when the pump shaft seal goes, then the hydraulic oil goes into the engine.

I understand, but what I was saying is that a number of engines have seawater pumps gear driven in this same manner but they have vents between the water seal and the oil seal to allow the water to spill out b/4 pushing past the oil seal into the engine oil. What I was questioning was why your hydraulic pump could not me made in that manner. Perhaps even with a fitting on the vent to carry lost oil to the bilge, a bucket, or even back to the tank.

 

[MDI45]

Actually, the aux drive is only on john deeres marine engines.

I have a gear driven steering pump on my Cat.....I wouldn't have it any other way.........but I guess guys have there own preferences