F-12 fuel pipe vent

[Chris NW Ind]

what's hollow ?

Sorry. Fritz suggested to take the vent apart to see what is in it. It's hollow. Has 5/16 fuel line going in from the pump and 9/16 or so dropping back down to the tee in front of the pump. The casting is hollow though.

 

[rustred]

Sorry. Fritz suggested to take the vent apart to see what is in it. It's hollow. Has 5/16 fuel line going in from the pump and 9/16 or so dropping back down to the tee in front of the pump. The casting is hollow though.

well yes , its a canister.

 

[Chris NW Ind]

Is there a particular measurement for the push rod length? Thanks.

 

[Fritz Maurer]

No length off hand, but you turn the engine until the rod is on high cam. At this point there should be enough rod sticking out so that the diaphragm moves when you try to push the fuel pump against the block. Sand the fuel pump mounting flange flat on a flat surface as they are almost always warped from trying to crush the gasket.... this will give a small amount of extra throw of the fuel pump lever.

If the rod is really short, carefully drill a hole in the end of it, and install a 6-32 self-tapping pan head screw in the end of the rod. You can make the rod as long as required by putting washers under the screw, and get all the stroke the cam has to offer.

Do not use a gasket. Apply a small amount of RTV to the fuel pump flange and bolt it solidly against the block. This way, the flange will never warp again.

 

[Chris NW Ind]

Thanks. I'll look into it.

 

[Chris NW Ind]

I've seen posts here and on RPM saying that rod could be anywhere from 6 15/16 to 7 1/8 long. Fordson house sells new replacements, no mention of length.

 

[Chris NW Ind]

My original question: what is the cap at the top of the vent? Picture? Not holding out for an original part but I'd to get close in appearance. Only picture I've found shows what appears to be a standard pipe plug. See attached.

 

[rustred]

pull the rod out and look at it, post a photo of the cam end. you will see the amount of wear. you cannot put a screw on the cam end. it has to follow the cam profile. they used to do the same thing on them old ford flatheads. definitly dont go over 1/8'' just use the trial and error nothing but time. i dont remember the length anymore. get yourself a bleeder from a diesel engine fuel filter, nice and neat.

 

[Fritz Maurer]

You don't put the screw on the cam end.

 

[rustred]

yes, but its such a small amount of wear that the screw head and lock nut would be over length.

 

[Fritz Maurer]

Don't use a lock nut either.

 

[Chris NW Ind]

I'm working towards checking this. Had the F12 running today and noticed the fuel pump base vibrating against the block. Bolts are tight for sure.

 

[rustred]

I'm working towards checking this. Had the F12 running today and noticed the fuel pump base vibrating against the block. Bolts are tight for sure.

i dont see how that can happen if the bolts are tight. have u pulled the rod out to check it, maybe someone has been working on that rod and its too long. plus you will see it move in time with the cam pressure , if thats whats happening.

 

[Chris NW Ind]

Either it's rocking because the base is warped as suggested earlier, or the rod is long as pushing it, I suppose. I'll get at it soon enough.

 

[SadFarmall]

This is the part that screws in. It has a small breather hole in it. Only fitted to kerosene F12 tractors, except very early ones, which had a setup similar to F14 kerosene tractors.
Usually the plug is missing and the casting is therefore full of rust and other foreign matter.
SadFarmall

 

[Chris NW Ind]

Thanks. That is what I was looking for.

 

[Chris NW Ind]

I got back into the F12. Pulled the fuel pump and did some measuring. Rod is 7 1/8" long, maybe a hair under. Noticed when I got the old pump on the bench the lever was broken and it definitely wasn't before. Also saw one of the diaphragm cover screws was too long and caught the lever and trapped it, maybe contributing it to it breaking. Finally, using the old rod and a brand new pump correct to the F12, I could it once again rocking against the block. This has to mean the long rod is bottoming out the lever and this may also have also contributed to it breaking. I got a replacement rod from Rice equipment, it measures 6 7/8. Not to mention, the fuel line from the tank has a substantial leak at the compression fitting.