The Stovebolt Site Forums The Parking Lot Big Bolts Carter Updraft Carb Rebuild Question

I am in the process of rebuilding my Carter Updraft Carb from my '46 Chevy COE. Yes, I have one of the incomplete rebuild kits....but it is better than nothing.

Anyway, from my shop manual it looks like the accelerator pump assembly should come out of the bottom half of the carb and stay attached to the top half of the carb. Whoever attempted a rebuild before me had the same problem and didn't put it back together correctly. But since I can't get it appart....I can't get it put back together correctly.

I have been soaking it in mineral spirits, gas, mineral spirits, WD-40 and Carb Cleaner, but I still cannot pull the accelerator pump assembly out of the bottom half of the carb. Any ideas.....???

Thanks,
Chevman

I haven't worked on an updraft automotive carb in years, but if you don't have any luck with yours, NOS updraft carbs appear on eBay quite often with very little bidding interest. Industrial updrafts don't have an accelerator pump.

Those get stuck rather frequently. Im not sure exactly how the Carters are setup, but with my Zenith, I soaked it in a little vinegar overnight and then used an air compressor to blow air from a passage on the bottom of the float bowl which cause the pressure to push it out right out.

On mine I broke the small circlip that attached the brass head to the shaft, and I ended up cleaning it up and was able to solder it.

In case I misunderstood, have you been able to remove the top half of the carb?

Jeff

Chevman - is the lower half of your carburetor zinc alloy or cast iron?

In any event, call during normal telephone hours (see website) and I will explain how to disassemble.

Jon.

I was able to take the top off because the PO pulled the pin at the top of the spring to let the plunger come off with the top and the spring aseembly stay with the bottom.

It seems to work this way and I think I could get it back together with the help of an extra pair of hands from home. I may just put it back together and let it go....???
Thanks,

Top half is cast iron and the bottom half is the zinc alloy. I will check the website and give you a call.
Thanks,
Chevman

Since the lower half is zinc, do the following:

(A) Remove the two pump check valves from the inside bottom of the bowl. These are the two closest to the pump
(B) Make a plug the same thread as one, and plug that hole.
(C) Make an open plug the same thread as the other, and tap for a grease fitting. Place this in the other hole.
(D) Apply grease from a grease gun to the fitting.
(E) Remove pump, 2 plugs, and wash out the grease.

It would have been easier if it were cast iron.

Jon.

carbking,
Don't keep me in suspense. I want to know what would happen if it were cast? Would it be to use the vinegar trick mentioned above?
Cheers
Super 55

Cast is much easier. Heat!

Jon.

I will try the grease fitting steps and report back.
Thanks,
Chevman

I started on step A on the list and ran into a problem right away...I was using a large flat screwdriver and I am unable to get either of these two check valves to turn. I did damage the screwdriver slot just a little on each one so I am hesitant on how hard I want to keep trying to get them out.

Advice ?? Suggestions ??

Chevman

I think the previous post from this morning just isn't up yet....but here is the update. I tried to get the valves in the bottom to unscrew with a large screwdriver and I am unable to get them turn at all. I am starting to damage the slot and so I'm not sure how much more I want to work on getting them out.

Another possible option that I am looking for comments on....if the pump is working as it should (and it appears to be working properly), do I just go ahead and see if I can get it put back together and use it as is? I believe I can turn the top half at 180 degrees while I am assembling the carb and get the pump acualtor rod hooked back up. Any one have any thoughts on that idea?

Thanks,
Chevman

No. That piston needs to move. When you start revving the engine higher, vaccum drops and gravity takes over letting that piston travel downward, which gives it a shot of fuel to compensate for the need of more power.

As mentioned above, I used vinegar to soak that portion of the carb overnight which dissolved most of the rust and gunk in the passage, letting the piston move slightly. Give that a go and try carbkings method with the grease.

Jeff

Finally, after about a week of letting the carb sit with plugs in holes and a grease zerk in one....and giving it a shot from the grease gun about every day....the accelerator pump finally came out!!!! Thanks CarbKing!!