Cat Pump 3545

[grouda]

I've read at least one thread regarding water in the oil but need further information. We just replaced the high and low pressure seals but are still getting water in the oil, almost right away, and it is getting very milky. It seems to be worse right after a wash and then once it sits idle for a while doesn't seem so bad.
Anyone have any ideas on why this is happening?

 

[mac]

There is another oil seal located between the crankcase and pump head. Go to Cat's web site and you can see the exploded view.

 

[cantbreak80]

A couple of other possibilities?

1. A cracked plunger
2. A damaged plunger retainer o-ring

Either condition will allow high pressure water to flow between the plunger and its rod. The water will then blow past the lip of the crosshead oil seal, into the crankcase.

You?ll likely see milky oil spewing from the vent hole on the oil cap if these conditions exist.

Cracked plungers are not always easy to detect, occasionally requiring removal to inspect. Loosen the plunger retainer 4 to 5 turns, and then push the plunger towards the crankcase. Once the plunger pops free of the retainer, remove the retainer and inspect it?s o-ring and metal gasket. Since it?s apart, replace the o-ring. Pull the plunger off the rod and inspect. If it comes out in several pieces you?ve found the crack. If the retainer o-ring has been leaking, the plunger rod will likely be quite corroded. Clean it off with a green Scotchbrite pad before reassembly.

Hope this is useful.

 

[grouda]

Guys, thanks for the info and we'll check it out this week and let you know what we come up with.