///One cylinder no longer makes pressure
Direct-drive plunger pumps

One cylinder no longer makes pressure

The controller sees one cylinder that does not contribute. Service is needed now.

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 3 checked
01Failed dynamic seal or carrier Most likely

The plunger seal or its carrier has failed.

How to check: Disassemble that cylinder.

PhotoArt. no.DescriptionReplaces OEMExcl. VAT
10377 End Cap Wrench, 8007923
KMT
KMT 80079239 € 70.80
10511 Dynamic Seal Assembly, SLPRO, 90K, 20479499
AssemblyKMT
KMT 20479499 € 159.60
11104 Maintenance kit, KMT intensifier tools, 05072723
Repair kitKMT
05072723 € 898.80
12661 Dynamic seal kit - Hyplex Prime, 050626-1
Seal kitKMT, Flow
Flow 050626-1 € 95.00
11489 Swivel maintenance kit, 007117-1
Repair kitFlow
007117-1 € 274.80

02Cracked check body or broken poppet Possible

Water flows back through the valve.

How to check: Inspect check valve parts.

03Broken plunger Less likely

The plunger broke near the collar.

How to check: Inspect plunger and crosshead.

Related problems

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