How often do you guys change your pump oil?

[ani68]

Are you referring to the high pressure, low pressure seals?

Both. I take care of 4 310's and 4 5CP2150W's (and one 3535!) and both types of seals are all in the same place in the manifold, so it just makes sense (to me) to change them all when I have it taken apart.

 

[ani68]

You shouldn't get any buildup from non-detergent oil. FWIW though, I use either Cat oil or a mix of three parts ND-30WT and one part transmission fluid (I always use it in General pumps since they're the most prone to failure that lets water into the crankcase). I started using that mix in customer pumps I repaired that had water in the crankcase, with instructions to change the oil after a week. I've been back to those washes months to many years later and saw the same pink oil in it because they had never changed it. I've been using the mix for 30 years in hundreds of pumps and have never seen any issues, and even saved my truck engine with it after it blew the intake manifold gasket and had pushed five gallons of coolant and water into the crankcase before I figured out where it was disappearing to.

That's good information! Thanks for sharing that.

 

[ani68]

I use ISO 68 which is essentially the same as Cat Pump oil, but more readily available (for me) and cheaper. It isn't the same as 30 non-detergent. You might get a sludgy build up if you used 30 weight for a long time.

What I actually meant to say here was that ISO 68 = SAE 20.

 

[SparklesSS]

Both. I take care of 4 310's and 4 5CP2150W's (and one 3535!) and both types of seals are all in the same place in the manifold, so it just makes sense (to me) to change them all when I have it taken apart.

How often do you change them in a year? Do you see signs of any breakdown or just automatically replace them? How many operating hours when you change your oil?

 

[ani68]

How often do you change them in a year? Do you see signs of any breakdown or just automatically replace them? How many operating hours when you change your oil?

When I can't get desired pressure (and everything else checks out ok), I change the seals. Often, one or two show some kind of wear (such as garter springs popped out or rubber torn a bit, etc). Otherwise, they are just worn out in the sense that they no longer fit snugly enough on the plungers to make adequate pressure.
The frequency seems to vary between pumps/bays. I've done some just once and others a few times. I haven't yet decided for sure if this is dictated by bay use or other variables. My instinct tells me it is probably a combination of both.

On the 2150w's, if I have to change seals/valves, I have to remove them from the pump stand due to logistics, and they are direct drive so I replace the oil then, too, in order to avoid a mess when swapping out the bell housings. On the 310's, I change the oil if and when it gets dark...maybe once a year. Same on the 3535.
Our carwash is very busy all year round, so they get a lot of use, but I haven't kept up with operating hours.