Available for: 1994 - 2010 CAT 3406E, C15, C15 Acert, and C16 Engines


PDI’s oil fill tube with locking aluminum cap were designed to prevent the cap coming loose from the old rubber “butterfly” style caps. 

The issue of the OE design was in the rubber, as it heated and began to deteriorate, it would lose its gripping ability and blow out of the fill tube. Costing owners $100’s of dollars in clean up, downtime and replacement caps. Not to mention frustration!

PDI started with casting a new aluminum fill tube that bolts directly to the front cover of the engine. This makes a much better location to pour oil vs. the valve covers and some on the passenger side of the engine. The fill tube is cast with a little different angle also, making a much better opening to pour the oil in smoother and easier.

The fill tube has a locking nub cast in it that interlocks with the billet aluminum cap, keeping the cap safe and secure. The cap features a serviceable O-ring to seal up tight with the fill tube for many years of leak free service!

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