Hi group, having a little trouble with a 310 ss pump. Won't make Above 900 psi. I have inspected valves, seemed ok, but plan on replacing them tomorrow. Changed the regulator thinking it maybe bypassing, old one was good. Hooked a hose and gun direct to the pump to test, and still only got 900psi. Belt seemed a little loose, but adjuster was as far spread as it goes, will try replacing that tomorrow too. Where else should I be looking as far as troubleshooting? Thanks
Cat 310 not making full pressure
- Thread starter Keno
- Start date
GoBuckeyes
Self-Serve and Automatics
Try putting a smaller tip in the gun just to see if the pump is capable of higher psi. If you get more thank 900 psi it’s probably not the HP seals.
Did you change pulley sizes?
Did you change pulley sizes?
cantbreak80
Maybe I need new clubs
Since this by-passes the downstream plumbing, my money goes to HP seals.
While you're in there, might as well replace the LP seals, too.
As cantbreak80 pointed out, I Bypassed all the check valves with the separate hose and gun and still only got 900psi. Brand new 2504 tip installed and no change. I cranked the regulator all the way up and never got above 900 psi. How would I confirm its the HP seals? Or is it just change them to confirm?
cantbreak80
Maybe I need new clubs
In my experience, water in the oil is due to cracked plunger or failed plunger o-ring.
High pressure water is forced past the lip of the oil seal and into the crankcase.
You have to remove the head to investigate so might as well replace the seals while you're at it.
MEP001
Well-known member
It could be the low pressure seals leaking and allowing water into the crankcase, but you will see water dripping on the floor if they're that bad.
If you want to save the pump, take it out of service right now and pull the head off. Push and pull on the plungers to make sure there is no in/out play. If it feels tight and there's no bearing noise when you turn it by hand, remove the plunger bolts and plungers and check them for cracks. If you find one (or more than one) cracked, order the replacement replacement plungers you need and all the o-rings, backup rings and the copper washers, those must be replaced anytime you remove the bolt. While you're waiting on parts, fill the crankcase completely full of transmission fluid and run the pump with the head off for a few minutes and let it sit for a few days. It does a great job of absorbing the water. When you put it back into service, fill it to the proper level with a 3:1 mix of non-detergent oil and transmission fluid and change it once a week until it comes out completely clear, then you can put regular oil back in it.
You might want to order all the oil seals, the water will rust the springs in them and they will break, at which point it will leak oil very badly.
If you want to save the pump, take it out of service right now and pull the head off. Push and pull on the plungers to make sure there is no in/out play. If it feels tight and there's no bearing noise when you turn it by hand, remove the plunger bolts and plungers and check them for cracks. If you find one (or more than one) cracked, order the replacement replacement plungers you need and all the o-rings, backup rings and the copper washers, those must be replaced anytime you remove the bolt. While you're waiting on parts, fill the crankcase completely full of transmission fluid and run the pump with the head off for a few minutes and let it sit for a few days. It does a great job of absorbing the water. When you put it back into service, fill it to the proper level with a 3:1 mix of non-detergent oil and transmission fluid and change it once a week until it comes out completely clear, then you can put regular oil back in it.
You might want to order all the oil seals, the water will rust the springs in them and they will break, at which point it will leak oil very badly.
I’d probably just replace the crankcase and move on. https://www.kleen-ritecorp.com/p-15...ear-assembly-with-plungers-for-310-pumps.aspx I’ve got a few 310 crankcases that I got from a closed car wash that every time a pump needed seals or the head would wash out they’d buy a new pump
Rebuilt the head with all new seals, orings, backup rings, and copper washers. Drained and filled oil with half and half Trans fluid and 30wt oil. New belts. Plungers all looked good, no cracks, showed some rust color on the side closer to the valves, but smooth. Running good now, pressure good, just making normal cat pump noise. Plan on changing oil again in a few days to see how it looks, probably do what mep says and keep the Trans fluid mixture going and change weekly until it comes out clean.
Hoping for the best, and hoping I didn't just waste a $100 seal kit.
Hoping for the best, and hoping I didn't just waste a $100 seal kit.
Quick update, pump still running good, I've changed the oil daily with the 50/50 Trans fluid and 30wt oil. Both times so far it looked like strawberry milk. Plan on changing daily until it comes out a little more clear.
MEP001
Well-known member
I like to keep changing it until it's completely clear, but I've rebuilt General pumps with the crankcase full of water, drained and filled it with the oil/trans fluid mix, and sent them back to the customer with the same instructions to change it, then went to their car wash as much as a year later and it still had the mix in it because they never changed it at all.
Haven't changed the oil this weekend, wash has been busy, going to do it first thing tomorrow. Sight-glass looks like a strawberry milkshake though.
I did look for washout, but didn't see any...though I have never seen washout in person, just through pictures online, so I may have missed it if it was slight washout
There used to be a "Sticky" Thread on the forum about 310 head washout with photos...Its not a Sticky any more but found it at the link below. Lots of good information in the thread.
(1) Washed out 310 manifolds - With pictures | Car Wash Forum
(1) Washed out 310 manifolds - With pictures | Car Wash Forum
Hi group, pump is running good. Have an oil leak though that has been getting worse over time on this same pump. It seems to be leaking between the crankcase and head. Having to refill weekly at this point. Any suggestions on what and how to fix? Thanks
MEP001
Well-known member
Piston seals, pretty easy fix but you need to be very careful getting the old ones out so you don't mar the metal piston. When you reinstall the plungers you need to replace the copper washer on the bolt, and it's a good idea to replace the o-ring on the bolt.
Moot point now, zero pressure regulator failed, starving pump of water for who knows how long. Pump is dead, no longer making any pressure. Should I try a rebuild with a new head? Or better off getting a replacement pump at this point?
MEP001
Well-known member
You should be able to replace the seals, valve o-rings, and oil seals for less than $150. If the pump got hot enough it may have melted the valve cages, but that's another $20 or so. No reason to replace major components.
