Hydraulic advice needed

Two gear pumps, a relief valve, a dump valve, a return filter and a reservoir. Hydrostatic transmission is better, with an oil cooler at least on the drain flow.

Concerns for the oil absorbing moisture over time.

Yes, you can. The displacement of the two pumps can provide the equivalent of "gearing" the speed up or down. Gear pumps are noisy, but very dirt tolerant.

David A. Smith

Jim-

Short answer is Yes

but I don't remember if we used two motors or two pumps....two motors I think

I / we did this a LONG time ago (~25 years) so I don't remember all the details but it did work.

here's a more recent thread that speaks to some of the details / issues

the supliier of your pumps (or motors) would know for sure

my gut tells me I would use two motors rather than two pumps; because motors are typically allowed to turn either direction ....where pumps might be direction limited.

If you've got the buy the units why not get one of each?

give Parker Commercial a call, tech sales

Thanks David & Bob ( and TNX ahead of time to any others that comment ). In regard to motors I notice a lot of them are rated fairly low RPM whereas pumps seem to be commonly rated higher RPM (I need). These components are not cheap (as I'm sure you know)and I have been watching ebay but sometimes specs are sketchy and it's difficult to match the numbers with manufacturers data. Jim H.

The ratings you see on the pumps/motors are not "red line" values. Gear pumps are rated to run at engine typical rpm, and gear motors are no different.

I find Grainger to have prices of less than $200 for each pump or motor (new). McMaster is apparently trying to retire, with prices higher than 5x that.

David A. Smith