Lubricating charge pumps turn out lubricating oil to bearings, gears and other parts. The oil acts as a coolant for the clutch plate and brakes. The operating pressure is around 300 PSI and the relief valve setting to 500 PSI when cold weather you need to start up.

You have scavenge pumps take oil from the transmission from the passageways to the sump pump and send it back to the reservoir where the charge pump is. Most times they operate on 50 PSI and are made to operate in poor inlet circumstances, huge vacuums and spray of air and oil.

Lube pumps are make to work high temperatures and at speeds of 4000 RPM. They can handle when the rpm fail or get damaged. These units are of a different breed of charge pumps that can handle one extreme to another. They are small in weight size also.

Call us at 800-361-0068 if you have other questions or email us at

sales@hydrostatic-transmission.cm