Carburetor leak
#1
10-17-2018, 06:07 PM
Carburetor leak
Hi everyone, a few months ago I decided to pull a 76 f-250 out of the weeds on the farm. When I first started working at getting it running the carb ( Holley 2-barrel 4412 on the 360) leaked from the fuel bowl so I decided to rebuild it. Now I have it back on the engine and it leaks from the gasket directly under it and also a little bit of seeping from the gasket between the spacer and the manifold. I have yet to have the engine started but when it turns over it leaks quite a bit directly underneath the vaccuum port in the front of the carb. This is my first rebuild and I’d appreciate some help or suggestions. Thanks
-Wyatt
-Wyatt
#2
10-17-2018, 06:30 PM
Those Holley float bowl gaskets are more fragile than they look. I'd pull it and check it. Then make sure you're torqueing it evenly. Other than replacing all the gaskets, I don't know what to tell you. Personally, I don't rebuild carburetors that have been sitting up more than a year. The price of a new one is cheap road insurance. Twice yearly I take my carbs off and clean them, replace gaskets, power valves on Holley / step up springs on Edelbrock, accelerator pump diaphragms, and re-jet as seasons change. They pretty much last a lifetime if you're using and maintaining them
#3
10-18-2018, 11:52 AM
Lead Driver
#4
10-18-2018, 07:38 PM
Cargo Master
Join Date: Jan 2006
Location: springfield Missouri area
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Possibly leaking from the accelerator pump gasket. This is quite common. Pull the pump plate with the arm, hold the side with the arm pivot against a straight edge. you will probably see it is cupped. Take pump plate and sit on something flat. Tap, (TAP) on top of the arm pivot with a small hammer( I use a small ball peen). little at a time and recheck, till you get it flat, reinstall and should be good to go.
#5
10-20-2018, 08:21 AM
As mentioned some castings and manufactured parts are not "true" and will not seal even with a new gasket. Check everything with a good known straightedge. When I rebuilt my 4350 there were imperfect castings which required a bit of "milling" to get true. This resolved the leaks. Sometimes (if nothing else gets upset) using two gaskets can help, but be sure it doesn't negatively change the carb's geometry in another way.
#6
10-22-2018, 11:00 PM
I’d like to thank everyone for all the help so far. The reason I haven’t been back here yet is because the battery I was using in the truck went **** up. I’ll be picking up a new one soon so I can get back at it. Also another question that I totally forgot about. While stopping the carb down inside the accelerator pump assembly there was a red piece of rubber or plastic that I pulled out. I’m worried that this may be the source of some of my problems. Thanks again guys!
#7
10-23-2018, 12:07 AM
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#9
10-23-2018, 11:37 AM
#10
10-23-2018, 04:16 PM
yes I got a new diaphragm. The old one was pretty finished. I didn’t get a new check valve though and that’s why I thought I might not need it lol
#11
10-23-2018, 05:15 PM
Lead Driver
#12
10-24-2018, 12:49 AM
Very similar to my procedure, except that I use graphite or anti-seize compound. It really makes disassembly much better.
#13
10-24-2018, 09:46 AM
Lead Driver
#14
11-05-2018, 08:26 PM
#15
11-05-2018, 08:57 PM
I'm glad you got it fixed!!!
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