Had a cat 310 with low pressure. I put in a new seal kit and it ran at 1200psi for about 2 weeks. Now it runs at 1200 till you squeeze the handle then drops to 900. Head problem? I inspected the head for wash out issues and it looks OK. Pressure regulator looks OK but is old. Any suggestions before I tear open a new seal kit.
CAT 310 problem
- Thread starter Jim64
- Start date
Now that you've done the easy fix it's time to move to the valves. Pull the valves out looking the "O" ring and the white "O" ring retainer, any debris under the valve disc. Also check the valve sitting surface for erosion, wash out. If everything looks good on the valves you've probably got a head problem.
MEP001
Well-known member
Before you throw any more parts at it...
Have you replaced the tip?
Does any water come out of any other bays with the problem bay running?
Does the pump run smooth all the time? Does it run smooth with the trigger released but pulsate with it pulled?
Is the pressure low on all functions, or it it low on soap but fine on rinse?
Have you replaced the tip?
Does any water come out of any other bays with the problem bay running?
Does the pump run smooth all the time? Does it run smooth with the trigger released but pulsate with it pulled?
Is the pressure low on all functions, or it it low on soap but fine on rinse?
MEP001
Well-known member
Possible, if the pump only pulsates when the trigger is pulled.
No backfeed, all the valves are good. The pulsating is very slight. Probably only a Carwash guy could notice it. I think it is in the head but I inspected for washout. Carwash pumps are like kids, they all have different personalities.
I'm kind of thinking you might have a head that's starting to or washed out. I'd probably pull it apart and take a long hard look at it. Look at the high pressure seal for any grooves along the side and on the sealing surface. Do you know what head wash out looks like?
MEP001
Well-known member
Check both the seal area and the valve seat area. If the o-rings blow out in a short time, the manifold is probably washed out there. They can be resleeved. Be sure to check the valves for cracks or debris.
Remember if you put a new seal kit a wash out head you've thrown away $80, because the wash out head will eat up the new seals. I'd get my hands on a used head, have it sleeved with stainless steel inserts.
These guys do a good job
These guys do a good job
Nope Cat won't resleeve a Cat 310 pump head. It'll cost you around $150 to have all 9 ports sleeved with stainless steel inserts. I like the way IDS does it by pressing the inserts into the head.
Last edited:
Send the head by US Priority mail, cost you $15.50. By doing the stainless steel inserts it should last forever. A new head from KR is $480.00.
I have a number of Cat 310 pump heads I send one and get my original head back. It takes about 2 weeks. It pays to have a spare pump head.
