[Craig Schafer]

I am doing an inspection of my Hydro-Gear PR-2KCD-GL1G (RT) and PR-2HCD-GJ1G (LT) pumps that happen to be on a Husqvarna PZ60 ZTR. I've noticed that on my manufacturer build, the hydro pump no longer includes a Valve Plate (52371) and in the service manual/drawings it is shown as optional. According to the service manual, on or after Serial #0216Pxxxxx in the PR series (and other models), the Valve Plate is removed allowing the Cylinder Block (72158) to directly wear against the PR Pump End Cap (72166).

Given that a 52371 Valve Plate is around $20-25 and is easy/fast to replace, whereas the Pump End Cap 72166 runs over $200, has anyone considered re-installing a Valve Plate with Serial #0216Pxxxxx and higher models of Hydro-Gear pumps? The only mention of change for Serial #0216Pxxxxx in the service manuals and parts appears to indicate that the Valve Plate is no longer installed from factory, otherwise the remainder of the pump is identical as far as I can tell.

Would this be of some benefit to keep down repair costs? Advice from anyone else in a similar situation, or knowledge of why Hydro-Gear stopped including the Valve Plate in latest models?

 

[Craig Schafer]

I'll also offer a theory for consideration:

My guess is that the Hydro-Gear 52371 Valve Plate is a softer metal part (bronze) meant as a sacrificial wear plate to be replaced at regular service intervals (e.g. at each the 500 hour hydro service) that would somewhat protect the other steel parts in the pump. However, in practice, Hydro-Gear found that owners/operators preferred the extended lifetime without the sacrificial wear plate given the gains in longer trouble-free operational time using direct steel-on-steel wearing vs. the lower cost of repair but at shorter intervals for the steel-on-bronze wearing when using the sacrificial valve plate.

As such, perhaps I could readily re-include the 52371 Valve Plate if I would like, but I would be back to shorter operational run-times between rebuilds/repairs, so not likely an overall benefit.

But that is just a guess, anyone actually know about this from experience in doing ZTR repairs on hydro-gear pumps?