I'm assuming you mean when you have a leak do you change them all. Myself, no, if a piston oil seal leaks I change all three, if a shaft seal leaks I only change that one unless I have to tear the pump down to change it, then I change them all.Do you change all the seals out at the same time?
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.
Definitely.Do you change all the seals out at the same time?
Are you referring to the high pressure, low pressure seals?Definitely.
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.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.
An old mechanic told me about it years ago for removing water from a car engine. I tried it on a General pump that had been shooting water out the dipstick/breather and after just a couple changes it was clean. After my truck's intake manifold let go, I changed the oil with the mix every day for a week after driving about 60 miles, after which it had no sign it ever had water in it. It also cleaned 300,000 miles of sludge out of it.MEP, Why that blend and what magical properties does it possess?