Perkins — Compression - Test
Testing & diagnosis · Basic engine
From a Perkins service manual covering: 402D-05, 403D-07, 403D-11, 403D-15, 404D-22, 404D-22T, 404D-22TA. Check it applies to your exact model before use.
Applies to: Perkins 402D-05, Perkins 403D-07, Perkins 403D-11, Perkins 403D-15, Perkins 404D-22, Perkins 404D-22T, Perkins 404D-22TA
Before you start
- Keep the engine rpm constant for all cylinders when taking a compression reading.
- Measure the compression on all of the cylinders.
Procedure
- Remove the fuel injector from the cylinder to measure compression for that cylinder.
- Connect a suitable compression gauge to the cylinder.
- Disconnect the fuel shutoff solenoid.
- Operate the starter motor and record the pressure on the compression gauge.
- Repeat for each cylinder.
- Repair procedures must be taken if the compression is lower than the repair limit.
Tools required
- compression gauge Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Standard at Assembly 2940 kPa (426 psi)
- Repair Limit 2450 kPa (355 psi)
- Compression pressure taken at 250 rpm
- Cylinders varying more than 350 kPa (51 psi) may be damaged
Full service-parts list: Perkins 402D-05 →, Perkins 403D-07 →, Perkins 403D-11 →, Perkins 403D-15 →, Perkins 404D-22 →, Perkins 404D-22T →, Perkins 404D-22TA →
Source: Perkins service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.