SPRING AS-GAS 4185942 - Caterpillar

Introduction
The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, use the solution that is identified below.Problem
There have been reports of piston seizures on C18 Engines with no apparent root cause. A failure mode of debris that is clogging the piston cooling jets has been identified.Solution
If an engine is being repaired for a piston seizure all the piston cooling jets must be removed and the piston cooling jets must be inspected. Run a piece of wire that is the appropriate size through the piston cooling jet in order to dislodge any possible debris before reinstalling the piston cooling jet.Note: The piston cooling jet that is removed from the cylinder with the seizure must be replaced.Refer to Illustration 1 for an example of the debris in the piston cooling jet. Refer to Illustration 2 for an example of the size of the debris that is needed to clog the piston cooling jet.
Illustration 1 g01952029
(1) Debris in the piston cooling jet
Illustration 2 g01952032
(2) Seized piston (3) Debris from piston cooling jet that caused seizure