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I had blocked the exhaust from crossing over because the paint burnt up irritated me. I am going to remove the blocks after I make sheet metal covers to shield that area and bolt it down by the two big studs on either side of the Xover area.
Then I can paint the shields the engine color and it will look original.

G'day dano55400,
to PackardInfo!

And, I presume from your Forum Name you have a '55 400? If so, I invite you to include your Packard in the Packard Owner's Registry here on PackardInfo.

Float numer 2 replaced... If that don't hold I'll have to try to solder the holes. So far the first one I replaced is holding.

Leaking gas from the atmospheric pressure valve, no idea what that's all about.

Figured out that I should have been plugging the vacuum this whole time and wasn't. I tell you... This is very mentally taxing.

Hank:

I can sympathize. Vacuum leaks in cars can drive you insane. The worst I ever faced was in my 1978 Lincoln Town Car. Vacuum powered all sorts of things on that car, including the door locks. Trying to track down leaks was like trying to herd cats -- it can be done, but what a hassle!

in this case it was easy to find, as i have nothing running off vacuum yet. i just forgot to plug it up so i wasn't sucking air and running lean.

Quote:
It's intended to vent vapor from the fuel bowl, but should only be open at idle.

Liquid fuel leaks above the air horn (bowl cover) gasket are most likely due to overfilling of the fuel bowl.

If the floats aren't leaking, but installed correctly and set to the right level, then you've got a problem with a needle/seat or too much fuel pressure.

Walk away for a bit - take deep breaths - look at the shop manual again (both the illustrations and text) - logic it out.

Are the atmospheric pressure valve and idle vent valve the same thing? If so there is an article in SC Vol30 #2 on gasoline fumes. It gives instructions on closing that valve off in 55 Rochesters if using a new gasket. I would wonder if that gasket is what is used in rebuild kits today and the valve should be closed off.

No doubt the SC gives good advice - seem to recall that vent was eliminated from the 4GC for 56.

However, the recommendations wouldn't solve the real problem if it's liquid fuel that's coming out of the vent.

its leaking from this valve...only not from the front...from where it presses into the horn. i may have to press it back out and put some sealer on it.

it is seaping from out the back side where it is circled and pooling up around that rubber nipple.

i checked my float level in the front by that spot through the inspection screw...it was fine, gas did not pour out when i took the screw out and i could see the float and gas level right at the bottom of the screw hole.

if that doen't work i'll use the top from my old carb...it doesn't even have this valve.

from what i can find on the net...its only for helping really hot starting and hot idling.

the other air horn i have is identical except this valve isn't there and nobody will see the top of the carb when the breather is on anyways.

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I can't claim to be super-familiar with the Rochesters but I don't see how gas can leak from there unless the needle and seat has failed, floats are sunken or leaking, or you have an overpressure from an electric pump, as the gasoline in the fuel bowl never gets as high as the pivot or the top of the pump opening in the cover unless you have a failure to maintain the proper fuel level in the bowls. IIRC correctly one of the differences between the 55 and 56 Rochesters was that the 55s have a linkage-controlled anti-percolator or vent valve and the 56s don't (vented internally).