///The pump runs but builds no high pressure at all
Intensifier: high-pressure side

The pump runs but builds no high pressure at all

Oil pressure is there but the water side does not come up. Something blocks the water or a large leak takes all the flow.

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.
1Check the causes, most likely first 0 of 4 checked
01On/off valve or cutting head open with a missing orifice Most likely

Without an orifice in place the water flows out freely and no pressure builds.

How to check: Check that an orifice is fitted and the head is assembled.

PhotoArt. no.DescriptionReplaces OEMExcl. VAT
10226 Orifice 0,10 mm, 1010
OrificeKMT
 KMT A2260004 € 11.26
10227 Orifice 0,12 mm, 1012
OrificeKMT
 1012 € 11.26
10228 Orifice 0,15 mm, 1015
OrificeKMT
 KMT A2260006 € 11.26
10229 Orifice 0,17 mm, 1017
OrificeKMT
 KMT 49863590 · KMT A2260006 € 11.26
10230 Orifice 0,20 mm, 1020
OrificeKMT
 KMT 49865850 € 11.26

02Inlet poppet broken or stuck Possible

If the inlet valve does not open or close, no water is pumped.

How to check: A cylinder that stays cold and makes no pressure on one side points to its inlet check valve.

03No inlet water Possible

Closed supply valve, empty supply or blocked filter.

How to check: Check the supply valve and inlet pressure gauge.

04Broken plunger Less likely

A plunger that broke near its collar no longer pushes water.

How to check: Unusual noise and one side without pressure; inspect after releasing pressure.

Related problems

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