Cat 310 low pressure and pulsating like crazy

[Keno]

Thanks for the info on the warranty and seal kits. My very untrained eye didn't see any washout, but good to know there is a warranty on the 5cp heads.

Got another problem now with 1 of the 310 pumps - it is leaking water between the pump body and head. Thinking those are the high and low pressure seals? Have some on order and plan to replace unless I am on the wrong track for the water leaking problem.

 

[MEP001]

Got another problem now with 1 of the 310 pumps - it is leaking water between the pump body and head. Thinking those are the high and low pressure seals? Have some on order and plan to replace unless I am on the wrong track for the water leaking problem.

It's either the low pressure seals or the plunger bolt seals. It will usually drip all the time if a low pressure seal is bad, but if it's a plunger bolt it will only leak while it's running and will usually get water into the oil.

 

[Keno]

It looks like plunger bolt seals included in the seal kit? I looked today, looks like it only leaks when running, and it's a sizeable leak. I'll probably replace all the seals while I'm in there.

 

[MEP001]

Yes, the 5CP kit comes with the plunger bolt seal. You should use Loctite on the screw thread and torque it correctly.

 

[Keno]

Which color locktite? This is for one of the 310 pumps. Will check torque specs

 

[MEP001]

Which color locktite? This is for one of the 310 pumps. Will check torque specs

Blue.

Torque specs are here: https://www.catpumps.com/sites/default/files/products/pdfs/5-15FSvc.pdf

With the 310 you only get the bolt o-ring in the kit. You MUST change the copper washer whenever you remove the plunger bolt, and you should replace the backup ring with the o-ring. https://www.catpumps.com/sites/default/files/2020-03/310_N.pdf

 

[Keno]

Blue.

Torque specs are here: https://www.catpumps.com/sites/default/files/products/pdfs/5-15FSvc.pdf

With the 310 you only get the bolt o-ring in the kit. You MUST change the copper washer whenever you remove the plunger bolt, and you should replace the backup ring with the o-ring. https://www.catpumps.com/sites/default/files/2020-03/310_N.pdf

Got the blue locktite in stock. Thanks for the references on the torque and parts.

I confirmed today that the leak is only active when the pump is in use, so it would be the plunger seals according to your earlier post. I have the seals, copper washers, and backup rings on order. Is there anyway to tell which plunger seal is bad? Or is it best to replace them all?

I plan on changing the oil after replacing the seal since it maybe contaminated with water - is CAT oil the recommended oil to use on the forums? Or is there something better available? The old owner left a bunch of sealed bottles of non-detergent 30W oil.

 

[MEP001]

If you can't see which one is leaking, you may just have to change them all. If you don't have one, you might want to get a spare plunger. It's very unlikely that it's cracked, but I have seen it happen on a 310.

30W non-detergent works fine, but if the oil looks milky at all change the oil with a 3:1 mix of ND30W and transmission fluid. The trans fluid will absorb the water in the pump, just change the oil with the mix until it runs out clear, will probably only take a couple of changes. General punps are so bad about leaking water into the oil that I would just leave the 3:1 mix in them all the time for when it would happen. If you want something as close as possible to Cat pump oil, get some ISO68 hydraulic oil from Tractor Supply. It's half the cost per ounce and no shipping cost.

 

[Keno]

If you can't see which one is leaking, you may just have to change them all. If you don't have one, you might want to get a spare plunger. It's very unlikely that it's cracked, but I have seen it happen on a 310.

30W non-detergent works fine, but if the oil looks milky at all change the oil with a 3:1 mix of ND30W and transmission fluid. The trans fluid will absorb the water in the pump, just change the oil with the mix until it runs out clear, will probably only take a couple of changes. General punps are so bad about leaking water into the oil that I would just leave the 3:1 mix in them all the time for when it would happen. If you want something as close as possible to Cat pump oil, get some ISO68 hydraulic oil from Tractor Supply. It's half the cost per ounce and no shipping cost.

I think there was a plunger in the ER, will get one on order if not. Thanks for the tip on the oil mix to absorb water and the TS ISO68. Will report back how I make out. Thanks for all the help thus far.

 

[Keno]

So the copper washers and plunger backup rings are on backorder until November at Car Wash Superstore. Will see if Kleen-rite or other source has them in stock. If I can't find any, I will just take the pump apart and replace the plunger o-rings and hope for the best. I can probably anneal the copper washers if worse comes to worst - used to do that with Aviation spark plug gaskets all the time to make the soft again so they would seal when reinstalled.

 

[Island_Landlord]

Thread is saving my butt years later- thanks all