Great Products Build Great Businesses

Since 1944, we have been helping our customers minimize production interruptions and maximize efficiency with the same care and expertise as if it were our own business.

Producing high-quality products and services is challenging and we know how hard it can be to find someone else who wants your business to succeed as much as you do. With industry-respected brands, $8 million of ready-to-ship components and assemblies and 24/7 support, we have the products to keep your business moving forward.

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Find Your Sales Representative

The John Henry Foster Company is a full-line fluid power distributor with territories covering parts of Missouri, Illinois and Kentucky and is the Midwest leader in fluid power sales. We have sales representatives stationed throughout our territory who can visit your site and provide hands-on attention to better meet your fluids power needs.

Common Hydraulic Failure Causes

Most often, failures start with hydraulic pumps. Studies show that 90-95% of hydraulic failures are caused by an increased rate of wear and tear on the pump due to:
  • Fluid contamination caused by foreign material in the hydraulic fluid.
  • Aeration and cavitation caused by improper design.
    • Restricted fluid flow to pump
    • Loose connection or fittings on suction line
    • Low hydraulic fluid level and/or low NPSHA
    • Excessive pump speed; be sure to check specifications of the pump and motor
    • Incorrect hydraulic fluid or wrong oil viscosity
    • Foaming oil and/or low or old oil levels
    • Clogged reservoir air breather vent
    • Too low of an oil temperature
    • Damaged or worn pump
  • Over-pressurization: subjecting a pump to pressures higher than its design specs call for.
  • Poor fluid viscosity: higher than required viscosity leads to cavitation; lower than required results in too much heat and leaks in the pump.
  • Excessive heat: heat can be either a byproduct of other failures or a trigger. It is always a warning sign that requires immediate attention.