Get the most out of your Gardner Denver Hydrovane compressor

PSV parts distributor, Imperial Engineering, gives advice on how to increase service life and reduce operating costs of Hydrovane compressors

Compared to a conventional diesel bus, hybrid buses are different when it comes to producing the compressed air for the braking and auxiliary systems, as they feature standalone electrically-driven compressors.

An OEM supplier to the hybrid market is Gardner Denver, which supplies its Hydrovane compressor range to manufacturers including Alexander Dennis, Optare and Wrightbus.

Unlike diesel engine-driven compressors that are lubricated and cooled by the engine’s oil circuit, Gardner Denver Hydrovane compressors have a standalone lubrication system. Hydrovane compressors also have built-in air filters and therefore require periodic maintenance for extended service life.

Routine servicing checklist

PSV parts distributor, Imperial Engineering, has identified the basic checks required on routine servicing to increase service life and reduce operating costs of Hydrovane compressors:

  • Regular oil level checks: Every four weeks is the recommended minimum interval. The compressors either have a sight glass on the side of the body, or a sensor connected to the CAN system. The oil level must be a minimum of three-quarters full on the sight glass at zero pressure. The sensor connected to the CAN system will display a warning on the dashboard if oil requires topping up, but it is also important to check the condition of the sensor/wiring during routine checks.
  • Sufficient air flow across the compressor is important to prevent overheating. Ensure there are no obstructions blocking the air flow and no excess debris build-up on the compressor’s cooling matrix (air cooled versions).
  • Check for any leaks in the air system, as they can increase the duty cycle of the compressor. Repair any leaks in the air system.
  • Check for excess oil carryover by visually inspecting air valves downstream. Carryover can be related to one of the following:
    • Oil separator cartridge or the separator air dryer unit cartridge requires changing
    • Compressor has excess oil.
  • It is essential to use the correct oil – Gardner Denver oil specification HPO-198.
  • Ensure the Hydrovane compressor is not running hot. Common hot running causes include:
    • Low oil level
    • Obstructed air flow
    • Blocked intake filter
    • Blocked air dryer or oil separator cartridge.

Technical advice on hand

Imperial Engineering has service kits to make servicing Gardner Denver Hydrovane compressors easier and more cost-effective, which include OE filters and HPO-198 compressor oil.

The firm also has a wealth of compressor system knowledge and works closely with Gardner Denver and approved service centre, PSI Compressors, to support operators with technical advice and guidance.

For further information, please call 01992 634255, email or visit