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TR2/3/3A AC Fuel Pump Lever

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71TR6

71TR6

Jedi Hopeful
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I'm rebuilding my original AC fuel pump and noticed part of the surface on the end of the arm that contacts the cam was rusted. I wire brushed the rusted area to see what was there and uncovered a pitted surface. I checked a spare pump I have that I'm rebuilding and that too shows some pitting. Is this something I should be concerned about? I don't want to risk chewing up a cam.


Pitted fuel pump lever.jpg



Thanks again!

Ron
 
What is the history on the fuel pump? Did the car sit for a long time?

In Georgia when we have a cold spell then it warms up there is condensation on every thing. Probable on parts inside the engine as well as outside the engine.

David
 
It won’t be good for the cam, but it will likely work. The load on the pump lobe is very low compared to the valve lifters. If I were rebuilding it I would work it on 120 grit paper to remove the pitting...then work it down to 600 grit to finish it.
 
John, you have gone in the way I was thinking but I would be just guessing to offer a suggestion along this line . I would be curious if it took 1/16" (.063) to clear up the pitting how much that would effect the fuel pump stroke and if that would be a problem. Once I get to my engine I may be facing this problem as well. Frank
 
I think the lever is always in contact with the cam lobe. You can feel the tension of the arm against the lobe as you insert the pump, so there is some stroke to spare. I would think 1/16" would still give full stroke, but can't say for sure. Sounds like something to check out at some point.
 
I find this situation interesting to think about, the fuel pump arm looks like brass and the cam is some kind of hardened something. The cam is round and the lever flat plus I am not sure how much surfaces of the both touch and where. I would not like it, but the 2 must have been rubbing for a while. I would think the hard metal would polish the brass. Plus how did the levers get like that in the first place. My guess is the brass at a molecular level is like particle board and falls apart in microscopic chunks and leaves behind what we see to the naked eye. The valleys and mountains might be ok with each other and the brass with very very small pieces fall off into the oil. Yes the forum has been slow lately and I have an open mind.
steve
 
The fuel pump sat in the car since the early 80s and I'm pretty sure the rust/pitting is from contacting the cam and going through multiple hot/cold/condensation cycles over the years. I'm a little hesitant to sand or file it down since it needs to be perfectly parallel when it sits on the cam or it might make things worse if only an edge rests on the cam afterwards. Since it is relatively light pressure, what are everyone's thoughts about surfacing the roughness with some braze and smoothing it?

Ron
 
There's really no need to overthink this; I'd just file it out and smooth it with sandpaper. That may not be as good as new, but you'll get many more years of life out of it.
 
I agree, just make it's surface smooth and don't worry about pits below the surface, they'll just be oil reservoirs.
 
Thanks for the input everyone! Yes, I think I overcomplicated/overthought this one. The sides of the lever are machined flat and provided a nice reference surface to sand out the pitting on the 6" wheel of my benchtop sander. It didn't take much and looks like it's supposed to now.

Thanks again!
Ron
 
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