IH 966

[Sscottbb]

We are not holding pressure when pumping manual bleeder. We put on new fuel filters and tractor runs fine for five minutes,then we bleed fuel filter and air comes out. I`m thinking the problem might be the O ring on manuel bleeder pump.Does anybody know what type O ring goes on manuel bleeder?

 

[rustred]

pull it out and take it with you to town.

 

[DeltaRed]

Ditto!

 

[wore out]

(quoted from post at 19:05:41 07/10/22) We are not holding pressure when pumping manual bleeder. We put on new fuel filters and tractor runs fine for five minutes,then we bleed fuel filter and air comes out. I`m thinking the problem might be the O ring on manuel bleeder pump.Does anybody know what type O ring goes on manuel bleeder?

There are SO many different O-rings by minute differences in size, to material (chemical/fuel resistance, ''hardness'') I would try to get the correct one from CIH, if at all possible for this application to have the best chance for a successful repair.

Look at Key numbers 148B and 148D, it appears the plunger seal is a special, ''square'' ring.

Details are shown for Key #148D.

If you if you have removed it from the injection pump, Key numbers 147 and 147A get involved.

 

[Sscottbb]

With that many O-rings they must make a kit. Anybody know if they do? Thank you for your previous answers.

 

[caterpillar guy]

I have to ask first are you ting it down before you start it after you pump it up with the jack pump? if not that could be part of your problem. IF you are then it should seal and not be a big deal. I would look for a leak in the filter gaskets or an o-ring seal in one of the line joints. Even possibly a bleeder not sealing when tight. A wee bit of dirt under a bleeder will not seal either.

 

[Sscottbb]

We never used the manual pump ever until we started getting air in the filters.We put new lines on a couple years ago.changed the filters a week ago when air got into filters, we then pumped manual bleeder to see if we could find air leaking,hand pump not getting hard when pumped; Yes we locked hand pump down before starting,when starting tractor fuel comes out filter bleeder fine than small amount of air follows maybe 5 seconds later,We are thinking air coming in from pump somewhere.

 

[Sscottbb]

Again tractor runs fine for about 5 minutes before getting air.

 

[Bob 7337]

Been a while since seen 966. It not gonna suck air from hand pump because it sets lower than fuel tank. If
primer pump was leaking it would leak fuel out on ground. Almost bet you have something in tank thus not
getting fuel and running bad

 

[Bob 7337]

if pump eal was leaking it would seep when setting there not running

 

[caterpillar guy]

Next time you start it remove the fuel cap and see if it runs longer if so then the cap is the problem. If not then you have a fuel delivery problem. If this has the check ball in the return might look into that. If not then no further concern with that. Have you looked into a plugged return line stopping it from running rather than air. I would put a rag in the fill hole with some air pressure not more than a few PSI like maybe 4-5 max. Watch for air bubbles or fuel leaking out at a joint in a line. you say you changed the lines. Did you change the return line? If so I think there is a deal at the tank for a restriction to keep fuel from flowing to fast from the pump. Did it get removed and not put back in? Is there any fuel leaks on the ground over night? If so they need to be addressed. Were the new lines steel or hose. If hose possibly they are collapsing inside from lack of fuel as they get sucked flat or a flap plugs the inside of it.