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-   -   Carb leak at choke location (https://67-72chevytrucks.com/vboard/showthread.php?t=816882)

Droff 01-13-2021 10:49 AM

Carb leak at choke location
 
1 Attachment(s)
I've got a manual choke Edelbrock carb that is leaking at one of the ports on that side. I don't have anything connected to the choke so it isn't being used.
I have little experience with carbs so I've only tightened both of the bolts on the side, don't want to go any tighter.

Would a rebuild kit address this issue or is there something else I need to look into?
Thanks.

Ol Blue K20 01-13-2021 11:43 AM

Re: Carb leak at choke location
 
What kind of leak? Vacuum or gas.

Droff 01-13-2021 11:44 AM

Re: Carb leak at choke location
 
Gas

geezer#99 01-13-2021 12:25 PM

Re: Carb leak at choke location
 
You got gas there, it’s flooding.
Multiple things to check.
Could be trash in needle/seat, stuck float, sunk float or the most common flooding issue with edelbrocks carbs which is too much fuel pressure.

Ol Blue K20 01-13-2021 01:00 PM

Re: Carb leak at choke location
 
Quote:

Originally Posted by geezer#99 (Post 8863599)
you got gas there, itís flooding.
Multiple things to check.
Could be trash in needle/seat, stuck float, sunk float or the most common flooding issue with edelbrocks carbs which is too much fuel pressure.

x2

Droff 01-13-2021 02:14 PM

Re: Carb leak at choke location
 
Quote:

Originally Posted by geezer#99 (Post 8863599)
You got gas there, itís flooding.
Multiple things to check.
Could be trash in needle/seat, stuck float, sunk float or the most common flooding issue with edelbrocks carbs which is too much fuel pressure.

Ok. There's a good chance it could be trash, I think I could use getting the tank cleaned.
So for the carb, as I said, not much experience. Just best to start with a rebuild kit or start poking around at each possible issue?
As far as fuel pressure, I've got just a regular fuel pump.
Thanks.

Andy4639 01-13-2021 02:30 PM

Re: Carb leak at choke location
 
As far as I know they don't make any kits that will fix the side bores on these. I had one a while back that the gas pedal linkage was sloppy. I called Edelbrock to see what to order. They said no kits available for these issue.

I found a local guy after buying a new carb. and he fixed it for me.
:chevy:

geezer#99 01-13-2021 03:15 PM

Re: Carb leak at choke location
 
Quote:

Originally Posted by Droff (Post 8863677)
Ok. There's a good chance it could be trash, I think I could use getting the tank cleaned.
So for the carb, as I said, not much experience. Just best to start with a rebuild kit or start poking around at each possible issue?
As far as fuel pressure, I've got just a regular fuel pump.
Thanks.

Start it up and look in the carb.
You shouldnít see any raw fuel while itís idling.
If you do let us know.
Do you have any rubber hose on the fuel line from the pump to the carb?

Droff 01-13-2021 03:48 PM

Re: Carb leak at choke location
 
1 Attachment(s)
Quote:

Originally Posted by geezer#99 (Post 8863698)
Start it up and look in the carb.
You shouldnít see any raw fuel while itís idling.
If you do let us know.
Do you have any rubber hose on the fuel line from the pump to the carb?

I'll give that a check.
On the rubber hose, yes I do. I've got a filter inline sitting along the frame and it's rubber from the filter to the pump. From the pump up it's about 50/50 hardline and rubber to the carb. I've got a second filter inline just prior to the carb.
The setup is how it was when I bought the truck, haven't done anything to change it.

geezer#99 01-13-2021 05:04 PM

Re: Carb leak at choke location
 
I’ve used a pair of pliers to gently squeeze rubber fuel line to reduce the flow. Acts like a fuel regulator. Less flow will likely stop any flooding you see inside. That will show fuel pressure is too high.
Sometimes when you release the hose the extra fuel can also help flush out any crap in the needle/seat.

mr.mud1 01-13-2021 06:01 PM

Re: Carb leak at choke location
 
hi,with regards to your carb problem.if it's leaking because it's flooding,as was already said you may have some crap in the needle and seat,not letting the flow of fuel stop or slow down when the float raises.i do a bunch of Quadrajets here and see one often that is flooding because the tank is full of crap.sometimes i am able to hit on the front of the carb by the fuel line with a rubber hammer,just easy and once in a while,the crap will dislodge and problem is solved,more often than not,i have to pull the top off and clean out the crap.sometimes you can get the air horn off without killing the gasket,sometimes,no such luck.if you have the carb apart,if it is stopped up with crap and it's dirt and rust and so on,the tank is dirty,but you might see bits of rubber,indicating a hose is failing.good luck.

Droff 01-13-2021 06:19 PM

Re: Carb leak at choke location
 
1 Attachment(s)
I've got fuel sitting on both sides of the carb when running, see arrows.

geezer#99 01-13-2021 06:32 PM

Re: Carb leak at choke location
 
Try the hose trick.
Might be need for a regulator.
Or float adjustment.

Droff 01-13-2021 07:21 PM

Re: Carb leak at choke location
 
Tried the hose trick, squeezed it for around 30-40 seconds, no difference in idle or level of fuel in the carb. I pretty much had it clamped, not just restricted a bit.
Need to go longer?

geezer#99 01-13-2021 07:41 PM

Re: Carb leak at choke location
 
Don’t hurt to try longer.

Droff 01-14-2021 02:16 PM

Re: Carb leak at choke location
 
I'll give that another shot but I figure I'll just cut to the chase and pull the tank to get it cleaned and coated as well as get a rebuild kit for the carb. I'm pretty sure I have a lot of crud in the tank, the filters get clogged fairly easy.
No point in leaving the carb out of the equation.
Thanks.

tim_mc 01-15-2021 09:43 AM

Re: Carb leak at choke location
 
2 Attachment(s)
As you may have read on this site and elsewhere, Edelbrock carbs don't like more than 5-6psi of fuel. I installed a regulator and gauge, which really helped. The VDO gauge was made in the USA.

I rebuilt a 1405 before switching to an AVS2 1905. They are easy to rebuild in my opinion.

Droff 01-24-2021 11:38 AM

Re: Carb leak at choke location
 
2 Attachment(s)
Got the tank pulled and looks like it was needed. Rust is worse at the bottom. I've got a rebuild kit for the carb and need to get the tank dropped off for cleaning/coating.
As far as the carb goes, any recommendation on cleaning the exterior?
This is my first go round with doing a carb job, I think I can do the monkey see, monkey do thing on the rebuild part with Youtube help but not sure how to make the carb look better.
Any suggestions there?
Thanks.

mr.mud1 01-24-2021 03:49 PM

Re: Carb leak at choke location
 
good deal,i figured your tank was full of crap.when i do carbs here,i dismantle them entirely,soak them in carb cleaner for a day or 2,rinse the pieces off with boiling water then blow it all out with compressed air and then it goes back together.if you're going to dismantle the carb completely,be careful,take your time and pay attention to the little parts and where they came from.you can buy carb cleaner at any parts store in a spray can.clean all the parts with the spray carb cleaner,you can use brake cleaner after that,there's a 100 ways to do it.if you were worried about getting it all apart,chances are,all your problem is in the float chamber.the dirt will collect there and on the needle and seats.you could cheat and just pull the top off and clean it out.nothing to it?
good luck.Greg

Droff 01-29-2021 07:17 PM

Re: Carb leak at choke location
 
2 Attachment(s)
I've got it torn down and cleaned up, the procedure wasn't too bad, plenty of Youtube help just to make sure I didn't get anything in the wrong spot.

Is there a starting point for both of the idle mix screws on the front? I thought I had seen three half-turns out as a start but wasn't sure. Going by where they were before cleaning it up, I'm a good bit off of that.

Also, in the second pic, should I adjust the Idle Speed screw and High Speed Idle screw so the primary is sitting at a certain spot or any kind of a starting point also?

Thanks.

mr.mud1 01-29-2021 07:39 PM

Re: Carb leak at choke location
 
i knew you could do it.i have no experience with these carbs but a carb is a carb sort of.when i do quadrajets,i always take the mixture screws out,one at a time,wire brush clean,gently and re-install them til they just bottom and turn them out a turn and a 1/2.they always start and then i adjust the carb with a vacuum gauge,i'm usually pretty close.i don't know about that low speed/high speed idle/are you sure that's what it has?i haven't done any of these carbs yet,maybe someone can chime in?i know most carbs,once the throttle is open passed the idle circuit,it's job is done?sorry i'm no more help.Greg

Steeveedee 01-29-2021 09:47 PM

Re: Carb leak at choke location
 
Once you clean it up nice, check to see how much wiggle you get, especially in the primary throttle shaft. The Edelbrock carbs wear at the throttle shaft bore and need to be bushed at about 40k miles, in my experience.

tim_mc 01-30-2021 09:57 AM

Re: Carb leak at choke location
 
Here's a link to the Edelbrock Performer & AVS carb owner's manual. I found it to be a good reference, especially for the float adjustment and calibration charts for dialing in the jets, metering rods & springs.

https://www.edelbrock.com/pub/media/...ers-manual.pdf

Droff 01-31-2021 09:42 AM

Re: Carb leak at choke location
 
I haven't noticed any excessive wiggle on the throttle shaft, it's pretty tight at this point.

Thanks for the link, I've found several sites for float adjustment and right now don't plan on fiddling with much else in the carb for performance.

I'm going to replace some of the fuel line but not all of it, what's the best way to get the old lines cleaned out before I start pumping fuel through them?

Thanks.

mr.mud1 01-31-2021 09:57 AM

Re: Carb leak at choke location
 
hi,sounds like you're making progress.the fuel lines shouldn't be too dirty,fuel flowing through them should keep them fairly clean?can you see inside the lines you want to clean?if you're not removing them to clean them or verify they're clean.you could pump some fuel through them just turning over the motor on the key but probably not safe to have fuel around like that if you had a spill,some fumes and a spark,it wouldn't be good.depending on what lines you're not replacing,and how hard it would be to remove them,just take them off and shoot some brake cleaner through them.check the condition of any of the rubber hose,that you don't have it breaking up in little pieces that will mess up a clean carb.all the best.Greg


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