The Perkins 4108 engine suffers from a chronic rear main seal leaking issue. The original white cotton Perkins 4108 engine rear seal is called a “rope” seal and is an obsolete design. Frankly, it is not adequate for the job and seals of this type are no longer used in marine or industrial engines. To address this problem, Foley has just introduced Version 2.0 of our Foley Hytork Perkins 4108 Rear Seal. This updated version is better sized and fits more easily in the 4108 rear seal holder than the original Foley Hytork 4108 diesel Rear Seal. This updated Foley 4108 Perkins rear seal kit features a teflon coated, braided nylon seal and includes a knife, a holder to use when cutting the seal, and installation instructions.