Topic: Oil Sight Glass

[gbran]

I've got a HydroTek SC with a Cat Model 56 pump. The dealer I bought it from told me I could change the oil in the pump once a year if I used Cat oil. Is this true or should I replace it more often? I only put about 500 hrs a year on it.
Also, the oil sight glass has become clouded, and it looks like it takes a special spanner wrench to remove it. Anyone know where I can get that tool or a better way to clean the glass. Thanks.

[Russ Johnson]

Every 500 hours is fine. You can use channel locks to get the sight glass out. If it's cloudy because of oil in the water, it'll wipe right off, but you need to address the front of the pump to prevent water from getting in (seals and / or pistons). If the plastic itself has turned white, it has gotten hot and may possibly shrink enough to fall out of the hole. Get a new one.

[bhenson]

Make sure when you change the oil its 10/30 non- detergent

[gbran]

Thanks for the help guys! I got the sight glass out with channel locks. I wasn't sure it was going to work because the glass was somewhat recessed in the pump body and it's a tight area to work in, but it came out easily. It was clouded up with black residue, but it wiped right off. I only use the Cat crankcase oil p/n 6101.

[Philip93]

Make sure when you change the oil its 10/30 non- detergent

That brings up a great Q for Russ.  My understanding of oil is that the detergents are there to break down fuel/carbon bypassing the rings in a combustion engine.  Since those don't exist in a pump, detergent oil isn't necessary.  But it shouldn't hurt either.  Is that the case? 

I've heard the old rumor about it foaming (even here), but I think that's just an assumption based on the word detergent.  Foaming oil (unless you over fill the case) just doesn't make any sense or a car engine crankcase would look like whipped cream.

[Gary Odum]

I have fairly a 20 hp Kohler motor and the valve's were slapping bad after I changed the oil.  I checked with the dealer and he told me to use a non-detergent oil and it would stop.  He said that the oil was getting hot and foaming.  I changed the oil and the noise stopped.

[Russ Johnson]

Make sure when you change the oil its 10/30 non- detergent

That brings up a great Q for Russ.  My understanding of oil is that the detergents are there to break down fuel/carbon bypassing the rings in a combustion engine.  Since those don't exist in a pump, detergent oil isn't necessary.  But it shouldn't hurt either.  Is that the case? 

I've heard the old rumor about it foaming (even here), but I think that's just an assumption based on the word detergent.  Foaming oil (unless you over fill the case) just doesn't make any sense or a car engine crankcase would look like whipped cream.

Detergent oils will foam up...not like shaving cream, but aerate enough to increase in volume, thus forcing some out the vent.

Plus, the oil in the pump is splashed around for lubrication, while an automotive engine forces oil through it under pressure.

If you've got a Honda single cylinder engine, fill the crankcase even to the top thread in the dipstick hole. Run it for 15 minutes, and check the oil. I bet it'll dribble out as if there were too much.

[Philip93]

I have fairly a 20 hp Kohler motor and the valve's were slapping bad after I changed the oil.  I checked with the dealer and he told me to use a non-detergent oil and it would stop.  He said that the oil was getting hot and foaming.  I changed the oil and the noise stopped.

Interesting. I'll grant you that it worked., but I'm not sure if foaming was fact or speculation. A small engine doesn't get significantly hotter than an automotive engine.  And if heat caused foaming, there would be a lot of cars with foaming issues. Particularly small high revving turbo engines, nearly all of which use detergent oil.  There's got to be more to it than that.

Detergent oils will foam up...not like shaving cream, but aerate enough to increase in volume, thus forcing some out the vent.
Plus, the oil in the pump is splashed around for lubrication, while an automotive engine forces oil through it under pressure.
If you've got a Honda single cylinder engine, fill the crankcase even to the top thread in the dipstick hole. Run it for 15 minutes, and check the oil. I bet it'll dribble out as if there were too much.

That makes more sense.  Foam isn't specifically the problem as much as entrained air increasing volume and making a mess of fluid control.