Contamination can be a cause of premature pump failure. Thus, cleanliness is a primary means of assuring satisfactory life out of a unit. J Thomas Distributors encourages all customers to follow the recommendations below to avoid such a situation.

**** ALL HOSES, MOTORS AND PUMP LINES MUST BE THOROUGHLY CLEANED WITH MINERAL SPIRTS.

****THE TANK MUST BE DRAINED AND CLEANED WITH NEW FLUID ADDED (REFILL WITH YOUR MANUFACTURER’S RECOMMENDED FLUID).

****CHANGE THE FILTER.

****INSPECT FANS (IF YOUR UNIT IS EQUIPPED WITH THEM) AND MAKE SURE THEY ARE IN GOOD WORKING ORDER WITH NO BROKEN FINS.

****PUMPS MUST BE PRIMED BEFORE USE.

Product or parts failures or malfunctions which are not attributable to defects in material and/or workmanship, and which are not covered by the said warranty include, but are not limited to:

* Inadequate, contaminated, or improper fluid.

* Accident, abuse, improper maintenance, or neglect.

* Stripped keyways, or splines stripped or worn on external shaft end.

* Improper mounting of external pulleys, gears, couplings, etc.

* Operating above those speeds, weights limits, pressures, or temperatures recommended         
   by Hydro-Gear.

* Use of the product in a manner or for a purpose not originally intended for by Hydro-Gear
  or failure to use in strict accordance with Hydro-Gear’s written instructions.

* Misdiagnosis of component failure.

All pumps are tested at the factory before shipping.
If a unit fails within warranty period please contact J. Thomas at 1-800-828-7980.

FLUID VOLUME AND LEVEL
Certain situations may require additional fluid to be added or even replaced. Refer to the vehicle manufacturers recommendations for the proper fill location and level. After maintenance or oil change follow purging procedures below and check the fluid level once the unit has been operated for approximately 1 minute.

FLUID CHANGE
In the event of oil contamination or degradation, oil addition or change may alleviate certain performance problems. Refer to the vehicle manufacturers recommended oil change frequency. Refer to purging procedures below after changing fluids.

FILTERS
An inlet filter is required to insure that only clean fluid enters the system. Refer to the vehicle manufacture for approved filter replacement.

PURGING PROCEDURES
Due to the effects air has on efficiency in hydrostatic drive applications, it is critical that air is removed or purged from the system. These purge procedures must be preformed anytime a hydrostatic system has been opened for maintenance or repair, or if any additional oil has been added to the system. Air creates inefficiency because it has compression and expansion rates that are higher than that of oil. Air trapped in the oil may cause the following symptoms:
1. Noisy operation.
2. Lack of power or drive after short-term operation.
3. High operation temperature and excessive expansion of oil, before starting, make sure the reservoir is at the proper oil level. If it is not, fill to the vehicle manufacturers specifications. The following procedures should be performed with the vehicle drive wheels off the ground, and then repeated under normal operating conditions.

1. With the bypass valve open and the engine running, slowly move the directional control in both forward and reverse directions (5 to 6 times). As air is purged from the unit, the oil level in the reservoir will drop.

2. With the bypass valve closed and the engine running, slowly move the directional control in both forward and reverse directions (5 to 6 times). Check the oil level, and add oil as required after stopping engine.

3. It may be necessary to repeat steps 1 and 2 until all the air is completely purged from the system. When the P Series Pump moves forward and reverse at normal speed and the reservoir oil remains at a constant level, purging is complete. Cleanliness is a key factor in the successful repair of pumps. Thoroughly clean all exposed surfaces prior to any type of maintenance. Cleaning of all parts by using a solvent wash and air drying is usually adequate. As with any precision equipment, all parts must be kept free of foreign material and chemicals. Protect all exposed sealing areas and open cavities from damage and foreign material. Upon removal, all seals, O-rings, and gaskets should be replaced. During installation, lightly lubricate all seals, O-rings, and gaskets with clean petroleum jelly prior to assembly. Also protect the inner diameter of seals by covering the shaft machined features with plastic wrap or equivalent.

WARNING: POTENTIAL FOR SERIOUS INJURY certain procedures require the vehicle engine to be operated and the vehicle to be raised off of the ground. To prevent possible injury to the servicing technician and/or bystanders, insure the vehicle is properly secured.