# JD 450E Dozer fuel problem



## Jeffrear (Jan 21, 2016)

I have a JD 450E Dozer. The RPM's were fluctuating and engine would sometimes quit running. Earlier today I changed fuel filter because of this very reason but it didn't help. I took side cover off again to check if filter had enough fuel. Thought maybe fuel tank had a restriction. It did have enough fuel , so I started engine and noticed air bubbles from to manual fuel transfer pump port on filter plate. 
Is this normal ? I used to have a 440 JD skidder and I never had any problem at all when changing fuel filter but never noticed if air bubbles came into the filter. Or do I have an injection pump problem ? I will say that when bubbles came into filter that engine RPM changed slightly while watching the filter.


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## HarveyW (Sep 15, 2014)

Hello Jeffrear, welcome to the tractor forum. 

RPM's fluctuating and engine quitting are symptoms of a blockage somewhere in your fuel system.

You need more that a trickle flow from your fuel tank. You need a "rush" flow.

There should never be any air in the fuel system. When you changed the fuel filter, did you purge the air out of it? There is normally a purging screw in the top of the filter mount.


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## jd110 (Nov 23, 2015)

There is a screen in the fitting at the fuel tank. It is possible that it is clogged there.


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