No return fuel to tank in Cat C9

[Bryan Beamon]

replaced the fuel pressure regulator and fuel filters .Ran a clear seperate hose from fuel pressure regulator into a container and now getting inconsistent fuel, sometimes fuel with bubbles and sometimes no fuel at all. Need help

[Eric Maclean]

Bryan
It sounds to me like you have a suction side line leak allowing the mechanical fuel pump to suck air instead of fuel.
First place to start is at your primary fuel filter or water separator.
If you have a Winn favor unit with the plastic sight glass screen filter they are known for leaks at the O rings on the sight glass.
Look for bubbles or foam in the site glass at fast idle.
I have heard that some of these coaches had a plastic fitting on the fuel feed line at the fuel tank which would degrade with time and leak.
Air in your fuel is a bad thing not only starving the engine of fuel and power but also the cooling the injector rely on .
There are threads on the forum here about the the Winn system and the O ring part numbers.
Hope this helps
Eric

[Bryan Beamon]

Thanks Eric, I have been in contact with Dave Atherton and he is assisting with our issues.

[Bryan Beamon]

A big thanks to Dave Atherton for helping us diagnosis our problems. We replaced all o rings on fuel pump, fuel primary filter and fuel tank as well as the fuel pressure  regulator. Another great bennett of the Beaver Forum.