Thread: Air Leak Saga

Hopefully my tale of frustration can help someone else out.

On a christmas roadtrip the engine spluttered and coughed (typical air in fuel) at the top of a mountain pass. It then kept on going for the last 100km of the trip with the occasional cough.
Spent an hour looking for a possible cause, found none. No fuel leaks to indicate air intrusion.

Replaced the spin-on filter and took off the old electric fuel pump under the passengers seat for a clean out. This was my downfall.
The pump was full of crud, but it was the factory method of attaching lines which screwd me up later.

So Still with no idea of the leak source I tried to drive home. It deteriorated to the point that that 80km/h I was pulling over to let it pump air through every 3km.

Made the stop and decided to hook up the old electric pump to find the leak. This was able to pressurise the main fuel line which normally only sees vacuum. One hose connector had perished and split on the inside, completely hidden from view and able to suck as much air as it wanted without leaking a drop of diesel. Until the pump that was. Sprayed diesel all over my engine.

Surprisingly repco were completely useless when asked for 3/8" fuel line. Salvation came from a hose-doctor I found parked up in an industrial area.

With the new line it made the remaining 300km with only one hiccup. But one hiccup is one too many.
When the wife tried to drive to work it died three times.

I finally found the culprit by leaving the electric fuel pump running while crawling underneath with a rag and torch. I found a slight dampness on the top line from the fuel pump.
On closer inspection I find the plastic fuel line is pushed onto a rough short piece of pipe with an external seam.

It is one of life's mysteries how this held for 24 years before finally leaking, apparently it's factory.
To sto it leaking required the pipe taken out and the seam turned smooth, the line heated with boiling water then pushed on and secured with a larger hose and hose-clamp.

If anyone else has one of these dodgy connections, hose clamp it now. The pressure from the electric fuel pump was enough to unseat mine.

Originally Posted by rijidij

Even the rare dodgy things you find on an Isuzu still last for 24 years Not bad hey !!!!!!!!!!

Almost... the nut fell off the front of my crank after 21 years.