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Water in Cat 3535 pump oil?

Rudy

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Last September, we changed the oil in every Cat Pump we have. I noticed today that the oil in my 3535's have a "milky" appearance. Isn't this most likely due to water getting into the crankcase somehow? What seals, if any, need to be replaced? Ideas? Thanks.
 

MEP001

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If there's no water on the floor under the pump, check and make sure nothing is leaking down onto the filler cap. Either the low-pressure seals or the plunger seals going bad can let water into the crankcase, but for sure with the low-pressure seals you'd see a leak too. If it leaks on the floor, but only when the pump is running, it's more likely the plunger seals.
 

Rudy

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Since my initial post, I read (on the internet) where condensation inside the crankcase can be an issue. This is something new to me....

Since the seal kits only come one way, I'm going to change the oil, and keep an eye on it. These pumps are like tanks. Mine are 15 years old, and haven't given me a bit of trouble.....
 

Kevin Reilly

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Rudy, if you check the back sight glass on the pump and the oil is still in the center of the red dot and has not risen then that's condensation from inside the machinery room. If the oil has increased in volume and has moved above the sight glass then it's time change the oil seals.
 

MEP001

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Rudy said:
Since the seal kits only come one way, I'm going to change the oil, and keep an eye on it. These pumps are like tanks. Mine are 15 years old, and haven't given me a bit of trouble.....
You can order only the low-pressure seals, but as I said above, if it's not leaking water on the floor they're probably not bad.
Kevin Reilly said:
If the oil has increased in volume and has moved above the sight glass then it's time change the oil seals.
The oil seals only keep the oil in the pump. They do not keep water out.
 

Rudy

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I changed the oil today. It doesn't look bad sitting in the pan. Makes me wonder if what I was viewing through the sight gauge was due to the pumps running. There are not external leaks....water, or oil.

Hmmmmm.
 

MEP001

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It shouldn't get milky looking through the glass even from running. The proper Cat oil won't foam up. I've seen the lens get cloudy from residue or from getting too hot.
 

Kevin Reilly

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Mep I beg to differ with you. There is a stainless steel "slinger" in front of the oil seal that provides back-up protection for the crank case seal. If the oil seal is bad and water is bypassing the high pressure seals it's going to get into the crankcase.

I don't know of any other scenario of how water will get into the crankcase. Restating what I said before if the oil volume doesn't increase in the crankcase but still turns milky white that comes from moisture in the room. If the oil seals are bad and if high pressure water is slipping through the seals then that of course will increase the volume of oil/water in the crankcase and you'll know it because eventually it'll start spitting out the top of that hole in the red cap when it has filled itself to capacity. Then the fun starts!
 

MEP001

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If the oil seal is bad, it'll leak oil. The oil seal is a V-seal which provides no protection whatsoever from water entering the crankcase, which is why the slinger washer is there in the event of a water leak. If water is entering the crankcase because of a water leak, that leak must be fixed to stop it. New oil seals will do nothing. "Beg to differ" all you want, I promise you that you're mistaken. Perhaps you're calling the low-pressure seals in the manifold "the oil seal."
 

jcedwards

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The cat pumps have 3 seals for the water to make it through: High pressure seal, low pressure seal (in the head), and the oil seal (in crankcase). The oil seal can bring in water to the crankcase and not leak oil out. The seal runs on a film of fluid and it does not matter what kind of fluid. Oil seals can handle a slight amount of pressure, but not much. This is probably why there is the 'tampon tube' in the 310's; to keep the oil seal from being blown out from old crankcase design. It does provide a benefit of an aquaduct for leaked fluid, though. The water slinger does little to nothing in this pump's design other than rust. My guess it that any water you are getting in is coming from outside the pump and not the result of seals in the head. If it were, there should be a puddle or a hell of a mess somewhere.
 

Rudy

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Right, or wrong, we switched from the expensive Cat oil to Non Detergent straight 30 weight several years ago (I think I read about that on this forum???). I've had zero problems in my 1010's, 623's, or 3535's. It was just the other day that I noticed the "slight" clouding in the 3535's, hence the posting on this forum. I changed out the 3535's oil yesterday, with the Cat oil.....and we'll see. At no time did I ever have any external leaking, nor did I have an increase in crankcase fluid. Maybe a slight amount of internal condensation is enough to "not mix" with the ND 30W oil....which from what I read here....the Cat oil should alleviate.
 

Kevin Reilly

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Rudy, We have always used Cat Oil in our pumps and if there is moisture or water getting into the crankcase it also will turn milky white. As I said in my original post if the crankcase filled up we replaced the oil seals and that solved the problem. If it was just milky but didn't increase the volume then we left it alone.

There's nothing wrong with using the oil you were using as long as it matches what Cat and the other pump manufacturers recommend.
 

Obeco1

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You can indeed get water in the crankcase , the Cat pump people call in "wicking" when the sleeve is going back and forth in the oil seal if any water gets on this sleeve it can wick into the crankcase this is very common on cat piston pumps. Brian
 
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