isc fuel pump and stumble

[hookliftpete]

(12-02-2019 )Signature620 Wrote:  What's weeping from the gasket, oil? And which gasket - The main fuel pump mounting gasket or the gasket between the main pump and gear pump?

These C series common rail pumps have those lovely ceramic plungers that end up fracturing. They aren't as disastrous as an ISX when they fail but they are quite easy to inspect. Just undo the four 12 point bolts holding the head on the pump and remove it. Pull the retainer springs off by hand and inspect the plungers for scuffing, cracks or fractures. Also push the plungers in quickly by hand - They should sort of bounce back at you. If they slip straight in and out without resistance then they aren't sealing - Replace the head.

Also check if there's fuel leaking from the weep hole on the gear pump (rear section) of the pump.

If the engine has done 10,000hrs or more then just get a whole changeover pump.

So it looks like it is different than I remembered...ha. To my eye, it appears that the pump is leaking on the lower part (nomenclature is not my thing) but not where I had thought. It seemed initially it was leaking at part 23 on the diagram (gasket), but now it appears to be leaking on the front side of part 14, at a bolt that is not named in the parts breakdown (arrow on engine photo). It is definitely fuel. Engine hours are around 5k.