Upgrading the hydraulic pump on a Harbor Freight towable backhoe trencher

Published at : 23 Dec 2025

How to upgrade the hydraulic pump on a Harbor Freight towable backhoe trencher. Went from stock 2.7cc pump to a 4.1cc Salami pump.

====== Pump: Salami Hydraulic Gear Pump ======
Model #: 1.6PB4.1D-R080S0
Alternative model #: 1.5PE4.1D-R80S0

(The 1.6 was superseded by 1.5. Both have identical mounts and port locations, but there are some cosmetic differences.)

Purchased from:
https://hydraulic-supply.com/1-5pe-series-gear-pump-610910342.html

====== Outlet hose adapter: 6MB-6FP ======
Purchased from:
https://biedlers-hydraulics.com/gates-6mb-6fp-g60275-0606-hydraulic-hose-adapter.html

Inlet hose adapter: 8MB-8FP
Purchased from:
https://biedlers-hydraulics.com/gates-8mb-8fp-g60275-0808-hydraulic-hose-adapter.html

Checkout my backhoe playlist for more videos on modifying and using this machine:
https://www.youtube.com/playlist?list=PLZdiIxStox_U_LMH42TM-iTewY5zprLt8