Carter AFB Acelerator Pump leaking

I've been postin with regard to the Distributor possibly being 180* out but I think I got it figured out for the time being so here goes with my next challenge, and as always I accept theees shallengge (A lift of the lynch lid to Inspector Cluseau....

So, Saturday I buttoned up the distributor and left all vacuum devices disconnected feeding from the carburator, plugging all of the ports as I went. Using the remote starter so I could see what's going on in the engine compartment, after two tries she started up! However I noticed fuel puddling on top of the Air horn on this AFB. I shut her down and mopped up the fuel drying the top so next try I could see where the fuel is coming from. Second go the fuel leak was from the accelerator pump shaft as it passes through the Air Horn at the point in this photo;


I seperated the Air horn (once again) from the Throttle Body and all still looked pristene, clean and free of any debris. I took note however that the Accelerator pump shaft's Neoprene rubber grommet does not seem to fit the "Acelerator Pump Well" enough to keep backfeeding or fuel out of the top. This is a new Acelerator Pump that came with the Echlin rebuild kit. In my searches the two sizes listed are 13/16 inch for the neoproene and 11/16 inch for the leather. The original pump that came with this 1988 mfd. AFB seems to be made of rubber and doesn't seal at all given it's shrunken size over the years.
As the AFB's go this one isn't ancient, using the old leather pumps (which are smaller anyway) are there different sizes of the neoprene cups available?

 

That looks like the correct pump for an aftermarket AFB (I've rebuilt many of them)
Is that the only place you're getting fuel?

 

Of many others I've seen online they seem the same as this one, but I'm dubious that Echlin may have their parts made in China, which could explain inadequacies I had on other parts made in China.
That's the last leak, earlier I had leaks at the Throttle Shafts, but when I was flush with cash I sent off the Throttle Body for bushing installation.

 

I would take the top off the carb ( leave the fuel in the fuel bowl) and push the acc pump down by hand & see what happens.

 

There's an Acellerator Dishcharge Check Ball resides in the bottom of the Acellerator Pump Well, isn't there?

 

I don't believe so...if memory serves, the accelerator pump check is under the squirter.

 

I've got that one, on this 9638 it's sort of a rectangular cylinder and I don't remember anything in the bottom of the Well except the Pump Plunger Spring. What got me going on this was a post;
"The only place I can think of that there might be a leak is in the accelerator pump. There is supposed to be a one way valve/ball bearing somewhere in the bottom of the pump - if this is missing or stuck open you could have a leak issue". from the http://www.chevytalk.org/fusionbb/showtopic.php?fid/72/tid/178227/pid/2600312/post/last/

As you can see, I'm going far afield to find a solution for this and I do remain dubious of that ball being in the bottom of the Well, but then again despite having this 9638 for many years, I'm no expert on the AFB.

 

IIRC the early AFB's (like you might find as original equipment on a 60's muscle car) had a Chek valve in the accelerator pump well....the newer versions do not.

 

Thanks for that clarification Colo.

So I reckon I'm back to figuring out the plunger and why fuel is getting past it and leaking out of the top

 

I got some vinyl tubing and a funnel and tested the Needle/Seats with the Air Horn inverted (gravity working on the floats) and ran fuel down the line.
The Primary Needle began leaking right away. From the many rebuilds of other AFB's I had a small collection of Needles and Seats

so I swapped out the needle and it held fuel. I don't know if I'm out of the woods yet, but this is just one more thing that was wrong with this 9638.

 

FINALIZED
Black Betty is on the trail again, idle down to 600, timing set and running smooth....at long last and several posts/counter posts, Thanks to all whom have posted their insights and opinions. But for one final pitfall, dropped the throttle return spring and it's lodged somewhere between the body tub and transmission. A quick trip to my best friends' place and it's now FINALLY on track. Now on to the mods before this issue began.