Oil Inquiries

Oil Inquiries

Popular Questions

• What type of oil does my pump require?
How much oil does the pump require?
When should I change my oil?
Why is my pump leaking oil?
Why is my oil a milky color? 


What type of oil does my Cat Pump require?

Cat Pumps requires the use of its specially formulated hydraulic oil. Cat Pumps custom blended crankcase oil is exclusively designed, tested and proven to maximize the life of Cat Pump products. This special formulated premium grade, petroleum-based, ISO 68 hydraulic oil contains an advanced additive package to protect against wear, oxidation, rust and corrosion.

  • Anti-wear additives protects metal to metal drive surfaces, extending drive life
  • High oxidative and chemical stability resists deposit formations and provides consistent fluid performance
  • Premium anti-corrosion additives offer protection in the most demanding operating environments

Cat Pumps Genuine Crankcase Oil Part Numbers:

Model Description
6100 Case of (12), 21 oz. bottles
6105 Case of (2), 2.5 gal. bottles
6107 (1) 21 oz. bottle
6109 (1) 30 gal. drum

Back to Top


How much oil does my Cat Pump require?


All Cat Pumps pressure wash pumps feature a oil bubble gauge located on the rear cover at the crankcase. Ensuring the pump is on a level surface, fill the crankcase until the oil level is in the center of the red dot.

If too much oil is added, oil will spit from the red fill cap. Although this will not harm the pump, reduce the oil level to center of the bubble gauge.

If you need to know how much oil is required, capacities can be found on pump data sheets. Click here to search for data sheets by your pump model number.

Back to Top


How often should I change my oil?

Optimum pump life is achieved by following Cat Pumps service recommendations. Crankcase oil should be changed after the initial 50-hour running period, then every 3 months or 500 hours thereafter unless a written waiver from Cat Pumps is issued based on application parameters.

Back to Top


Why is my pump leaking oil?


To properly diagnose an oil leak, you must first determine the source. Find your source below to determine proper fix.

Oil Cap - If the source of you leak is out the top of the oil cap, the oil level is too high. Drain oil until level is at center of bubble gauge.

Between crankcase and manifold - If the source is in this area, the oil seals are worn and are in need of replacement. Replacement part numbers can be found on data sheets by clicking here.

Back to Top


Why is my oil a milky color?


If the pump is allowed to run after the low-pressure seals and high-pressure seals have become worn, water may eventually travel back along the plunger rod and past the oil seal. Water is a contaminant to the crankcase oil and can cause damage to the drive-end components. The water will cause the oil color to change to a milky consistency initially and in severe situations can cause damage to the drive-end. Remember to replace the plunger retainer O-ring each time the seals are replaced. The plunger retainer O-rings are supplied in the seal kit for the pump.

Back to Top



Search For:
Model #:
Type of
Flow Rate:
  gpm lpm
  psi bar
Drive Type:


1681 94th Lane NE
Minneapolis, MN 55449

Call Now

p. (763) 780-5440
f. (763) 780-2958

Contact Us