Water/Fuel Glass Bowl Filter Not Filling with Fuel

 Ask Dave / Posted 4 months ago / 67 views


I have a 1996 Beaver Patriot Cat 3126. It has a Winn Coleman fuel system. The glass bowl is not staying full like there is too much air. Sometimes it is hard to start. I push the air purge button and it tries to fill but takes a long time and only fills a little, The water purge does not seem to work as the light does not come on like the air purge light. What do you think the problem is?


Dave’s Answer:

There are several reasons the Winn Coleman glass bowl is not filling. One very common reason is that the unit hasn’t been properly maintained and the O-rings (4) need changing. Deteriorated O-rings can allow air to enter the fuel system. Changing them is not a difficult procedure for do-it-yourselfers. If you’ve replaced the O-rings and the glass bowl is still not filling, there is a simple way to test for air in the system. Connect a hand vacuum pump to the Winn Coleman outlet fitting and block one outlet. Try pulling a vacuum on the fuel line. If not successful, air is being pulled in around the new O-rings. This is the main entry for air in the fuel system. In most cases the higher horsepower engines with the single stage piston pump will pull more fuel, which can be the cause. The surface of the O-rings and the seating radius will not hold back much vacuum. Remember that there cannot be any air entering the fuel system.


I suggest you replace your current Winn Coleman system with a Cat water/fuel filter. This should solve your problem permanently. If the Winn Coleman system is not maintained, it can allow air into the fuel system. The presence of air in a fuel system on an engine with a HEUI injection system can cause low power and/or damage to the injectors.

The Cat replacement is a 131-5671 water/fuel filter group. A breakdown of the parts included is 137-4367 filter base, 133-5673 water separator filter, 129-0375 water collection bowl. You will also need 2 plug and fittings for the filter base. These can also be obtained from Cat.

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Fuel System

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