Overview
This manual includes information on the installation, maintenance, and minor repair of H1 pumps. It
includes a description of the unit and its individual components, troubleshooting information, and minor
repair procedures.
Performing minor repairs requires the unit to be removed from the vehicle/machine. Thoroughly clean
the unit before beginning maintenance or repair activities. Since dirt and contamination are the greatest
enemies of any type of hydraulic equipment, follow cleanliness requirements strictly. This is especially
important when changing the system filter and when removing hoses or plumbing.
A worldwide network of Danfoss Authorized Service Centers is available for major repairs. Danfoss trains
and certifies Authorized Service Centers on a regular basis. You can locate your nearest Authorized
Service Center using the distributor locator at www.Danfoss.com.
Warranty
Performing adjustments and minor repairs according to the procedures in this manual will not affect your
warranty. Major repairs requiring the removal of a unit’s center section, servo sleeves, or front flange
voids the warranty unless a Danfoss Authorized Service Center performs them.
General instructions
Remove the unit
If necessary, remove the unit from the vehicle/machine. Chock the wheels on the vehicle or lock the
mechanism to inhibit movement. Be aware that hydraulic fluid may be under high pressure and/or hot.
Inspect the outside of the pump and fittings for damage. Cap hoses after removal to prevent
contamination.
Keep it clean
Cleanliness is a primary means of assuring satisfactory pump life on either new or repaired units.
Clean the outside of the pump thoroughly before disassembly. Take care to avoid contamination of the
system ports. Cleaning parts by using a clean solvent wash and air drying is usually adequate.
As with any precision equipment, you must keep all parts free of foreign material and chemicals. Protect
all exposed sealing surfaces and open cavities from damage and foreign material. If left unattended,
cover the pump with a protective layer of plastic.
Replace all O-rings and gaskets
Danfoss recommends that you replace all O-rings, seals and gaskets. Lightly lubricate all O-rings with
clean petroleum jelly prior to assembly.
Secure the unit
If removed from machine, place the unit in a stable position with the shaft pointing downward. It
will be necessary to secure the pump while removing and torquing fasteners and components.
Safety Precautions
Always consider safety precautions before beginning a service procedure. Protect yourself and others
from injury. Take the following general precautions whenever servicing a hydraulic system.
Service Manual
H1 Pumps 069/078, 089/100, 115/130, 147/165, 210/250
Introduction
©
Danfoss | May 2018
520L0848 | AX00000087en-US0308 | 5
