Cat pump seal replacement

[Stuart]

I have 530 cat pumps. On one of my pumps the oil seals for the plungers need replaced. Has anyone successfully replaced the seals without disassembling the crankcase? Having to disassemble the crankcase just for 1 seal is a real pain.

 

[DiamondWash]

When I buy a seal kit for my Cat Pumps I don't just do the one valve that's bad I replace them all because if one is going out the rest are soon to follow.

 

[cantbreak80]

Oil seals cannot be replaced from the "wet end". You're gonna have to disassemble the entire drive end.

That said...what are the symptoms? Oil dripping? Crankcase filling with water? Oil looks like chocolate milk?

 

[MEP001]

You can replace the oil seals without disassembling the crankcase, but you have to be very careful not to score the piston when prying out the seal.

 

[Stuart]

I have one seal that is leaking from a recent oil end overhaul. If the oil was compromised I would be doing another overhaul. I do replace all seals on overhaul however this seal has been a short lived one.

Getting a new seal in is not the problem- it is getting the bad seal out. I know it would be a tricky task to do, I am wondering if anybody has done it?.

 

[MEP001]

You can pry it out by turning the pulley so the piston is all the way in and carefully twisting the blade of a screwdriver under the seal and resting the shaft of the screwdriver on the shoulder of the piston, then turning the pulley which should pop the seal out. You can easily scratch the piston if you aren't careful, and once it's scratched it has to be replaced or it will continuously chew up the seal.

It's really not that hard to take the crankcase apart, just make sure it goes back together the exact same way it was. You should also replace the washer, o-ring and backup ring on the plunger bolts when you have it apart as the washer is meant to be compressed only once and won't deform properly again to seal.

 

[DRsuds]

You can pry it out by turning the pulley so the piston is all the way in and carefully twisting the blade of a screwdriver under the seal and resting the shaft of the screwdriver on the shoulder of the piston, then turning the pulley which should pop the seal out. You can easily scratch the piston if you aren't careful, and once it's scratched it has to be replaced or it will continuously chew up the seal.

It's really not that hard to take the crankcase apart, just make sure it goes back together the exact same way it was. You should also replace the washer, o-ring and backup ring on the plunger bolts when you have it apart as the washer is meant to be compressed only once and won't deform properly again to seal.

Do you have a picture by chance? Im pretty sure I did this once before but I want to be sure its the seal I'm thinking of, the location I need to service right now only has 4 bays so I want to minimize downtime. I'm currently just topping off oil.

 

[I.B. Washincars]

MEP passed away about two weeks ago.

 

[DRsuds]

MEP passed away about two weeks ago.

Im sorry to hear that. Thank you for letting me know. He was a really nice guy, saved me a lot of headaches.

 

[Greg Pack]

The oil seals are located in the crankcase. If you remove the head and look where the plungers go into the crankcase you'll see them. Replacing them from the outside can be kinda tricky but can be done.

 

[DRsuds]

The oil seals are located in the crankcase. If you remove the head and look where the plungers go into the crankcase you'll see them. Replacing them from the outside can be kinda tricky but can be done.

I think I’ve done it on my 310 pump by drilling a screw into it and using vice grips to pull it out a couple years ago, if it’s the 3 ring seals all the way back. I’m assuming it would be the same thing for a 5cp. I don’t think I’ve ever openned one of our 5cps but I assume they’re the same general design. They seem to last much longer. But it’s a different location so there could be other variables.