[Squirrelhunter#1]

It may indicate the water pump bearing needs to be replaced or the water/oil pump (no longer available) shaft needs replaced and that requires complete engine disassembly.

Wow! Is there ever any good news when it comes to one of these Polaris machines? Every time I start to fix what appears to be a small problem, it turns into a major ordeal. Thanks for the information. It's a good thing I bought an extra engine, to overhaul and to use as a (QEC) Quick Engine Change. It seems easier to change the engine than to fix some of these "small" problems. I'm still trying to get the old mechanical water pump seal out, without damaging the shaft or case.

What would be the result of a malfunctioning one way valve?

Thanks for the information.

 

[Squirrelhunter#1]

You do need to realize that you are working on an older machine and replacement parts where in finite supply from the start.
Any manufacturer will only support any given model for so many years.
No manufacturer can afford to stock every part for every machine indefinitely.

Yes I do. Just a little frustration. Life happens.

 

[Squirrelhunter#1]

I blueprinted that pump shaft for possible re-manufacture, but they will cost $400 each if order 100 and $300 each if I order 1000. I don't feel the demand is there unless I could get a company in China, India or Taiwan to re-man them.

Wow! That's a chunk of change for a water/oil pump shaft.

 

[Squirrelhunter#1]

This is the best oil flow chart I could find.

View attachment 196972

Thank you Lateburd. This is exactly what I needed to see how the oil flowed through the system. Have you had the opportunity to inspect one of the one way valves. I'm just imagining that there is a ball and a seat, with the ball being held against the seat with a spring of pre-determined strength. Then when the engine starts turning the oil pump, that it has enough hydraulic pull to pull the ball off of the seat. I'm thinking that when the engine quits turning the oil pump and the hydraulic pull is weakened, the spring overcomes that hydraulic pull and pushes the ball back onto the seat. I'm just guessing, but in your experience, you can probably tell me if it works this way or not. My thinking is that if that spring weakens, over time, and allowed the ball to be unseated, gravity could cause the oil to flow from the tank and allow some residual oil to build up in the bottom of the crankcase. I'd be interested in your opinion if it works this way, or if it works in a different way. Thanks for sharing your experience and knowledge of how these machines really work.

 

[Squirrelhunter#1]

Custom manufacture - starts off with a 32 mm diameter x 183 mm long blank and requires lathe, drill and threading operations.

This is the rough draft of the part

View attachment 196976
If your part is not broken and the part of the shaft the seal rides on is worn, it can be repaired by having the OD welded and turned back to it's original diameter, or reduced in diameter and sleeved back to the original diameter. There are several options, but re-man of the complete shaft is not cheap.

Thank you for this drawing of the oil/water pump shaft. I can see that it would require numerous machining operations. I appreciate the suggestions on repair methods. I'm hoping that after I replace the oil and water pump seals, my problem will be solved. All of the information you provide is very helpful and I appreciate it.

 

[Squirrelhunter#1]

View attachment 196978

Thanks, this is excellent. Do you recall if you ever had to replace the spring or seating fixture for wear or a weak spring?

 

[Squirrelhunter#1]

I have never had to replace a check valve and have only heard of the problem - I believe there is a thread on here that describes replacing the plunger valve with 2 steel balls.

Thanks, I'll take that lack of any failures to mean; "if it ain't broke, don't fix it".

 

[Squirrelhunter#1]

I can only speak in regards to my machines, both are 2001 Polaris Sportsman 500 HO. Yes, both of my machines have a lower case (sump) plug that gets most of the residual oil out. However, it's not at the lowest point in the bottom end case. On mine, the plugs are on the lower right side of the engine. Yours may differ significantly.

I'm hoping a water/oil pump kit will solve the problem, after I replace both the oil seal and water pump seal. But, thanks for the information on the Plasma Metalizing process by Purtec. I'll keep that in mind if I have to tear the engine completely down and split the lower case.

 

[Squirrelhunter#1]

Note: there is no advantage to draining the sump and could potentially damage the engine if the oil pump were to lose it's prime due to sucking air. It's highly unlikely, but it's why Polaris specifies pinching off the oil tank vent hose so crankcase pressure will force oil into the pump if the pump fails to pick up oil from losing it's prime.

Thanks for that good information Lateburd. It sure looks like the risk outweigh the advantage, if there is any advantage, of removing the oil sump drain plug.