Swing: three tests before you take the motor off.

Test 1 — relief pressure at the swing port

Tee a 0–60 MPa gauge into the swing relief port and stall the house against the swing lock. Compare with the catalogue rating for the motor (34.3 MPa rated, 41.2 MPa peak for M5X130CHB). More than 10 % low: the relief is passing, and the motor is innocent.

Test 2 — brake release

A dragging parking brake heats the motor housing and mimics a worn motor. Check pilot pressure at the brake-release port and listen: a brake that does not open fully takes the housing past 70 °C within 15 minutes of work.

Test 3 — case drain

Run the motor at relief for 60 seconds with the drain into a measuring container. Flow, not pressure, is the wear signal. If the drain is dry and the swing still drifts, look at the centre joint seals and the swing spool before the motor.

Two photographs decide the order: the machine plate and the motor plate. The full TYPE code, not M5X130 alone — the FRG11 and FRG14 swing devices differ in reduction ratio and brake.