One of the best truckmount pumps ever is the Cat 290. If your unit uses a 290, leave it alone! We rarely rebuilt one or had any problems under 10,000 hours. Didn't even change the oil unless a seal leaked.
They don't work so well for last stage chemical injections and pressure washing, so manufacturers replaced them with other pumps. The 3CP, 5CP, Comet pumps... reliability not so good. Rebuilds or catastrophic failures were common at a thousand hours, and the Cat rebuild cost almost as much as a new pump.
The General
Emperor HTX we bought for trial purposes in 2003 is still running at 6,000 hours with no problems, and we've specified that pump for every truckmount since.
HydraMaster now uses the
Emperor as their stock pump so we don't have to special order them anymore.
I'll thank Larry Cobb for the tip on this pump every time the subject comes up.