Sumner and list members,
Last week I finished replacing/rebuilding a fuel pump on my TR3.
I found the axle pin on the pump arm to be about 3/4 of the way out so
that the pump arm was able to rock sideways.
Inside there was no seal between the diaphragm and the mechanics.
This pump was a Canadian built aftermarket pump with out the priming
lever.
I had three pumps with priming levers that I was able to make one from.
Two of the pumps were of the unrebuildable type where the valves and
seal were swaged in place. One pump was the rebuildable type. I used
the rebuildable top and a non rebuildable bottom to make one pump.
The rebuildable bottom had a seal that had hardened to rock.
What I believe was happening is that the diaphragm had become porous
from the "new" gas. The car was unused for 9 years. The gas leaked
through the diaphragm to the chamber connected to the block and then
past the nonexistant seal into the sump. The oil was then diluted to the
point that the bearings started to make noise.
Normally the seal inside the pump will prevent fuel from traveling into the
engine and there is a weep hole in the pump body to allow the fuel to
drain out. The outside of my fuel pump would get dirty with a fuel and
oil mix after driving the car.
After having driven the car several days the gasoline smell is not present
and the engine noise is very much less. Still planning on tearing down
the engine this winter. But I feel much better about the unknown noise.
A bit of fuel pump trivia. I noticed that the unrebuildable pumps had a
laminated actuating lever and the rebuildable pump had a solid lever.
Does this hold true for the majority of pumps? This would make it much
easier to spot a rebuildable pump.
Does anyone know of a source for the seal? I have heard that it is
made of unobtainium. Would there be any long term harm from not
having a seal?
Thank you for all the suggestions about the unknown noise.
Roger
Roger Colson
57 TR3 TS21383L
sassamon@mediaone.net
http://people.ne.mediaone.net/sassamon/TS21383L
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