Most faults on high-pressure pumps have a small number of clearly identifiable causes. Anyone familiar with the typical symptoms usually finds the source within minutes – and prevents a minor issue from turning into bearing damage.
Service and operating manuals are available as PDFs for every pump model on the relevant product page, reachable via the pump finder. For factory repairs, see our repair service.
What maintenance intervals apply to CAT PUMPS high-pressure pumps?
Check oil level, oil condition, leaks, running noise and temperature daily. The first oil change is due after 50 operating hours, then every 3,000 hours or at least once a year using CAT PUMPS crankcase oil ISO 68. Seals and valves are replaced as required – depending on running time, pressure, fluid and water quality.
My pump no longer reaches pressure – what can I check?
The most common causes, in this order: worn or oversized nozzle, air ingress on the suction side (check fittings), clogged suction filter, faulty or misadjusted unloader or regulating valve, worn valves or seals. A faulty pressure gauge can also simulate pressure loss – when in doubt, cross-check with a reference gauge.
Why has my system suddenly started to pulsate more?
Usually the pulsation dampener's pre-charge has dropped; it should be about 60 percent of the operating pressure. Check and recharge the pre-charge, or replace the dampener. The second typical cause is foreign matter in the inlet or discharge valves.
What does milky oil in the crankcase mean?
Milky oil indicates water in the oil. The cause is either condensing humid air – remedy: a new oil cap and an oil change every 3,000 operating hours or every six months – or heavily worn seals allowing water into the crankcase, in which case a new seal kit is needed. In both cases, change the oil immediately.
What does leakage at the manifold mean?
Water dripping from the manifold is the classic sign of worn high- or low-pressure seals. A new seal kit solves the problem. If service life is repeatedly short, the underlying causes should be checked: water quality, temperature, inlet conditions, scoring on the plunger or dry running.
My pump knocks or runs rough – what causes this?
The most common cause is insufficient fluid supply at the inlet due to an undersized line, air ingress or a clogged filter – in other words, incipient cavitation. Other causes are inlet or discharge valves stuck by foreign matter or, when the noise comes from the crankcase, a worn bearing.
May the pump run dry?
No, never. Dry running destroys seals and plungers within a short time. Before every start-up, make sure the pump is supplied with fluid and the crankcase is filled with oil to the middle of the sight glass.
Are CAT PUMPS pumps difficult to service?
No – the pumps are designed to be exceptionally service friendly. Seal and valve changes are generally possible on site without special tools; for some models, optional special tools are available that make servicing even easier.