stewart vaccum tank

[Chris Coon]

Anyone have any light to shed on repairing or replacing the 'needle/seat's, I have a tank that leaks past both the vaccum side and the vent.

Chris

[HarryJ]

Chris, Could you be more specific as to the problem?

[Mark Shaw]

It is unlikely that both would leak at the same time, so I doubt that the needle seats are the problem.

First you need to examine and/or test the pot metal top casting for hairline cracks. You can use a few pounds of air pressure and a gauge to see if the can leaks. Or just coat the inside of the casting with Krazy Glue (it is impervious to moder gasoline). Make sure the sealing surfaces are still flat and use a new gasket & re-test.

If that doesn't fix the problem, you can then try to fix the valves. Some light grinding compound might work to mate the needles to the seats, but first check to make sure the mechanism is not bent and is working freely to allow the needles to go straight into the seats.

[tblack]

Chris...many times the little bushing that guides the valve on the vacuum inlet loosens up and falls down....the symptom is that it draws so much gas that the engine loads up rich.

If this is the case put it back in place and lightly prick punch the pot metal around it this usually is enough to keep it in place.

Of course this requires disassembly and Mark points out other things to look for

[Fred Rawling]

Use fine polishing compound like you would use to polish brass mixed with paint thinner or kerosene. I went as far as removing the float and walking beam so that I could get to the valve easily and lippe it in.

Do not use valve grinding compound no matter how fine it is. You can make it worse if you cut the valves too much. Valve grinding compound is for grinding, not polishing. As previously mentioned, look for rust through holes in the inner tank and make sure your new gasket on the lid is sealing. I put a light coat of permatex on it when I re assemble it.

Also you can check the valves with a rubber hose on the vent tube and then move that whole fitting to the suction side to check the suction valve.

Do Not use teflon tape when re assembling the fittings on the tank top. Teflon is a lubricant and you will not feel or know that the fitting is too tight untill you crack the tank top.

[Guest frazer51]

Chris...many times the little bushing that guides the valve on the vacuum inlet loosens up and falls down....the symptom is that it draws so much gas that the engine loads up rich.

If this is the case put it back in place and lightly prick punch the pot metal around it this usually is enough to keep it in place.

Of course this requires disassembly and Mark points out other things to look for

Hi, thanks for the great tip. My 1918 Buick which I had just finished about 2 months ago would run just fine for a while then at times it would act like I had the choke on. After I read your post I said that is my cars behavior. After I removed the vacuum tank top I saw the bushing hanging down. I did as you said, then put it together and took a long hard ride with no problems. This Buick will get to see alot of the highway from now on. Thank you, John.