///Overstroke alarm or the pump strokes too fast
Intensifier: high-pressure side

Overstroke alarm or the pump strokes too fast

The pump strokes faster than normal because water is lost somewhere: inside the pump or after it.

Safety first: Switch off the pump, release all pressure (open the on/off valve or bleed-down valve) and lock out before you open any high-pressure part. Never put a hand or tool near a running jet.
1Quick questionsYour answers put the most likely cause on top.
Is it fast in one direction or both?
2Check the causes, most likely first 0 of 4 checked
01Internal leak in one cylinder Most likely

A leaking seal or check valve on one side makes that stroke fast.

How to check: Note which direction is faster; check that side's temperature and weep holes.

PhotoArt. no.DescriptionReplaces OEMExcl. VAT
10084 Spring LP-Inlet SLIV/SLIV+, 49884562
SpringKMT
 KMT 49884562 € 4.32
10085 Spring Check valve, 05147863
SpringKMT, H2O
 KMT 05147863 · KMT 49894116 € 1.90
10088 Flat Outlet Poppet, 05116561
PoppetKMT, H2O
 KMT 05116561 · KMT 05112776 € 31.80
10089 Retainer, Poppet, LP-IN SLIV, 10118552
PoppetKMT
 KMT 10118552 · KMT 05144670 € 42.29
10090 Spring Guide, Poppet, 05116751
PoppetKMT, H2O
 KMT 05116751 · H2O 102008-1 € 37.80

02Orifice too large or worn Possible

The orifice asks for more water than the pump delivers at pressure.

How to check: Compare orifice size with your pump's maximum.

03External leak after the pump Possible

Leaking fittings, on/off valve or bleed-down valve.

How to check: Check the whole HP line for drips and the bleed-down outlet for flow.

04HP seal failing Possible

A seal that leaks only under pressure gives fast strokes before it drips.

How to check: Watch weep holes at full pressure.

Related problems

General advice based on manufacturer manuals and service practice. Always follow the manual of your machine. Not sure? .