Air in fuel HJ45

[oralocsa]

I keep on getting air in the fuel in my diesel HJ45 truck. What's the most likely culprit? Am I right in thinking I have to replace the fuel pump?

 

[duncanrm]

If fitted.. the most likely culprit is the factory sedimenter unit mounted to the main chassis righthand rail under the drivers seat, they rust out. Other things to check are:

• Injector return - soft line
• Crush washers on the banjos for the fuel filter and fuel inlet (especially if these have been disturbed recently and not replaced
• Primer pump leaking
• Soft line from tank to sedimenter
• Soft line from chassis rigid line to lift pump.

Also.. a fuel restriction is often misdiagnosed as a "sucking air" problem.. so you should also check the gauze mesh inside the banjo fitting at the injection pump inlet, and of course your lift pump has possibly failed (rare, but it happens, these are easily replaced and the lift pump fitted to the 2H is the same pump).

 

[oralocsa]

Thanks for all your suggestions. I'll check it out but it will take a while as it is an old truck on a holiday property so I have to wait until next visit.

It is definitely air sucked in as I can see it when I bleed it. And lots of it. After I bleed it, it goes for maybe 10 minutes and then stops again. I thought of a leaking primer pump, but how do I check that other than replacing it?

As must be obvious from this I'm an absolute novice when it comes to diesel.

 

[duncanrm]

I thought of a leaking primer pump, but how do I check that other than replacing it?

Pump the primer.. if you see diesel leaking externally.. replace it. Around $50 for the bosch unit, easy changeover.

 

[Michael B]

A fellow cruiser head had a similar issue recently on his H motor. It turned out to be the soft return line from the the pump to the tank.

 

[oralocsa]

Thanks guys. I'll check it out.