Matt Gruber

i can get 15 years on a full rebuild, but there is usually something minor that needs attention, so....
about 5 to 10 years is my experience.

ctjackster

do you mean serious leaks, or the odd drips drip here and there?

I've had a few Holleys on my 65, and while none of them were serious leakers, all of them were prone to a drip here and there, which adds up over time.

66BlkBB

I have found that if I open a Holley for any reason I will get some type of leakage. I have had the 4770 on the 66 for over 5 years now and have never attempted to open it up. Haven't had a leak to date. Crossing my fingers. I've had a Street Avenger on my 32 for 10 years now and I haven't opened it up. No leaks on it either. Don't know if this is true for everyone but seems to be my experience.

Steve

Matt Gruber

well
my concern is for a fire hazard.

i can make any carb drip:
pump the gas pedal a bunch,
DON'T start it.
gas will weep out the shaft,and drip on the manifold.
without a heat isolator, on a hot soak same thing can happen.

When it is running, vacuum sucks gas in around the shaft, and a good set up won't leak. If it does it is likely flooding. minor flooding might not leak, but major it justs shoots out.
If gas drips out a "cool carb" engine shut off, this is a serious fire hazard.

Steve
what u say makes sense, sometimes if u re-use the gaskets, even tho they look ok, they leak.

David Preston

Great to see this question.
I have a very original 67 with the 327/350hp engine and I seem to always have a leak with the carb. Carb is original.
I have rebuilt it twice but, it always leaks. It does not leak when running but seems to leak after it sits. The intake will have dark colored gas on both sides when I go back in the garage after it sits a few days after driving. I would guess it is about a tablespoon of the gas on each side.
Does anyone have any suggestions??
Thanks
David

Matt Gruber

David
i just fixed the same exact thing yesterday on my 72.
Let's see who else knows the exact cause of this

QUIZ:
GIVE THE CURE FOR DAVIDS PROBLEM

66since71

knock on wood... I am up to about 20 years on a then new Holley for my '66 327/350. The only leak is out the vent on top of the primary fuel bowl. Every Holley I've ever seen with that vent leaks there.

My guess on Dave's problem: First shaft bushings, then the primary fuel bowl vent??

ctjackster

that sounds oddly familar

zim64

I've had a 3310 on my car, for the last 8 years. I have been into it more than a couple times. The first time I took it apart, I put the blue nonstick gaskets in it, and have reused them every time. I put a secondary metering block on it also. I use the blue gaskets on the metering block to body, and bowl to meteing block surfaces. I use the hex head screws to hold the bowl on, with the black washers under each head. These I replace every time I take it apart, and don't overtighten them. Just snug them down with a nut driver. I would check to be absolutely sure the body or base plate aren't warped. This can be a contributing factor to leakage, as well as worn throttle plate shafts, carb bowl mating surface, metering plates etc. each should be checked thoroughly for flatness, and free from burrs etc. Do these things thoroughly and you have a pretty good chance of stopping the drips. Oh and also check your float level. It should be at the bottom of the sight plug with engine warm and idling. Of course this usually leads to leakage while doing this, so put a towel on the manifold to suck it up. And adjust the float level very carefully, or it will spray out around the nut on the float screw. Yeh that was a surprise the first time I did it.

Bluestripe67

Mine hasn't leaked since 1985....I put it on the shelf. Dennis

66BlkBB

####################################

You probably have the best cure!!!!!

wow

OK Matt, we are all in suspense here...what's the answer?

David Preston

Come on Matt what is the answer?????

6T7L71CPE

As noted in my HOLLEY LEAKS post, John Z stated that the body/metering block or plate surface must be "dead flat". Mine wasn't and it had some pitting. I flattened my with sandpaper and a piece of granite. I've only driven it once so the jury is still out. Mine didn't pour out the shafts but dripped out the 2300 secondary idle openings into the manifold.

ctjackster

methinks, from other threads, that these leaks be coming from shafts.

Shaft

He's a bad mother. . . . .

Shut your mouth!

I'm talking bout Shaft!

427435

I fought leaks from the fuel bowl on my trips for years. Tried double gaskets and everything. Problem basically was that the 2 barrels had warped from heat cycles. Took them off and milled the surfaces flat that the metering plates and fuel bowls mounted to. No more leaks as the bodies have evidently warped as much as they were going to.

So, while the 4 barrel bodies are a lot stiffer, you might want to lightly mill the surfaces that you're getting leaks from.

Coves4me

Having used Holleys for many years on the Mustangs i used to own, I found that there are several minor items that MUST be done when running this carb. I've never had Holleys leak if the following things were performed after a rebuild.

1. Make sure that the thin plastic bushings are installed on the throttle shafts where they go through the base casting at all three locations. If not, a vacuum leak and fuel leakage will occur.

2. When installing the float bowls, make sure that the gasket surfaces are free of all old gasket and sealant material. There is a cast in raised ridge around the primary and secondary bowl sealing surfaces that must be retained for a proper seal against the gaskets.

3. Use the blue re-usable gaskets that Holley or the aftermarket sells between the float bowls and the main body and the primary/secondary metering blocks. I believe Holley was calling these BUNA-N type gaskets. You can use the Holley supplied original gaskets, but they are very difficult to remove from the castings after many years of use.

3. Use nylon bowl screw gaskets (aftermarket) on the exterior side of the float bowl screws when re-assembling.....AND use an inch-pound torque wrench when tightening the bowl screws in a criss-cross procedure. After tightening the bowl screws to the proper torque, re-tighten them after 4 or 5 engine run cycles as the gaskets tend to relax and will require re-tightening to prevent leaks. DO NOT use any sealant on the bowl gaskets.

Doing these simple assembly tips will go along way toward keeping the carb from leaking. Good luck.

highschool67

I have had problems in the past with O rings between the float bowels drying up.

chris ritchie

I didn't grow up in a car culture. We lived in the city. Never took shop in high school. Came to this late. Only started fooling around with cars in my 20s. So, whenever there's a problem, I assume the fault's mine. I screwed around with a Holley carburetor for 20+ years. New from the box until the day I threw it away.

What a relief! All these years I thought I was doing something wrong. Blue gaskets; rubber gaskets; silicone or grease on the gaskets; extra "O" rings; tighten the screws; untighten the screws; adjust the levels; etc.. What a relief to discover that these things are crap. Bought an AFB, and never looked back.

Dale Pearman (RIP) recommended that the best fix for a Holley was to place it on a kid's tee ball tee and hit it as hard as you could with a baseball bat.

Trophy Blue

It's been one year since the rebuild with no leaks but, the power vavle went bad so, I have to replace it once the weather warms up.