Leaking Carb

I'm guessing you have too much fuel pressure from the electric pump. Try to run it from a can sitting on the cowl and see if the problem goes away. The vacuum tank is a neat item that uses just a little gravity to feed the carb. If gas still pours out of the carb when using a gas can, then you have a problem like a leaky float or a bad needle and seat. Is that a cork float? If so, it may be saturated and needs to be replaced.

Have a nice day
Steve

They have a brass float,anything over a 1/2 lb will make the carb leak

Many thanks to both of you for your very valuable info. Yes, it is a brass float, which I have checked out. I agree, I think it must be a pressure prob. But will check it as suggested. If so I will have to learn how the original arrangement can be replaced. alternative work a way to reduce the pressure,
Kind regards, PeterJeffery

Rick, I do not understand your comment about anything "over 1/2 lb will make the carb leak". Are you saying anything over 1/2 lbs/sq in(psi) or over 1/2 pound force? Please be accurate - units are critical - you know that RICK. I am sorry I may seem to be picky but I want accurate representation. Thank you Rick for your all your contributions.

Thank you Paul for raising this as I (in the UK) have been scratching my head as to the units. In order to reduce the pressure being delivered, I see I can get hold of fuel regulators that adjust between 1 and 5 psi. These would seem to be greater than the value that Rick is suggesting I need to get down to. Currently the modification fitted is a low pressure bulk head SU, which I believe pushes out fuel at 1.5 psi.
Obviously, in the end I will wish to re-install the original vac system but initially I just wish to run the engine to assess all that is right or wrong with it and to be able to enjoy a little motoring in the new acquisition.
Thanks and regards to all those who are being so helpful.
Peter

I think all of us that have a basic knowledge of mechanics know that pressure created by a fuel pump, and therefore the pressure in the fuel system, is measured in pounds per square inch not a unit of weight. Not necessary to be that specific.

I recommend you get the vacuum tank back in service. I had a Hudson with this and it worked great. It is sort of like a carburetor; it has a float to control the fuel level in the tank. It is also a great conversation piece and ingenious.

That's what I'd do!

Steve

Hi Steve,
Yes, I agree and would like to do this in time. I would be prepared to engineer one but do not even know what it looks like. Can you give me a lead into this? Have you got one fitted? Is there a photo or blow up of one available?
Thanks for your comment.
Peter

Some info:
http://www.allpar.com/fix/fuel/vacuum-t ... -pump.html
much more available just google it.

Parts: http://www.classicpreservation.com/vactankkits.html

Keep you eyes open and you will find one. Lots of cars from the late teens, 20's and early 30's used these.

Good Luck
Steve

Thanks Steve, now understand. Great web site and also found a nice demo on you tube. I will definitely be looking out for one. Cheers, Peter

Les, I obviously know the mechanics from my statements in my post. I just like accurate units/measurements. I was thinking that maybe 1 lbf was too much for the float needle and the needle got destroyed. So units are important as our buddy from the UK indicated he appreciated the clarification. So please please quit the superfluous comments. I am not discussing this any further. Rick knows but not everyone does. Let us use the proper English language and units. I will go to MKS or CGS, if you would like.

For Les, brief and abrupt statements (lb vs psi) do not work in Engineering and building equipment/construction. It is force or pressure. I know what you mean with the psi and lb as far as they are used, but it is not a good practice. I am going to send you a PM.

Hi All,
I just wanted to thank Rick, Paul, Steve and any other who contributed to this item. On suggestion, I ran the car from a can and there was no leakage from the carb therefore concluding that it was a pressure problem due to the electric modification.
I purchased the fuel pressure-regulator, set it to half of 1 psi as suggested, put a filter ahead of it in line and the engine starts and runs without leakage of petrol.

Currently focussing on bleeding the brakes and then will assess whether they work well or need refurb. Next will be water pump which is leaking somewhat around the spindle.These May end up new items. Just wanted to say how helpful it is being in touch through this site with fellow DeSoto owners around the world.

All the best and Happy and safe Motoring. Regards, Peter

For Les, brief and abrupt statements (lb vs psi) do not work in Engineering and building equipment/construction. It is force or pressure. I know what you mean with the psi and lb as far as they are used, but it is not a good practice. I am going to send you a PM.

Paul, we are not discussing engineering and building equipment/ construction here. The topic is about pressure in a fuel system on a car. That is measured only in psi and a discussion or explanation on psi versus force is totally irrelevant to the topic. If someone asks you what time it is it is not necessary to tell them how to build a watch. There was no reason for Rick to explain that he was talking about psi. I didn't get a pm from you. Please send it so I can respond.