I know something is leaking, because I hooked up my Mity-Vac on the little hose from the vacuum reservoir and it couldn't hold vacuum for very long at all. When I blow into the system, however, it seems to hold pressure.

Any suggestion for how I track down the elusive leak? All the diagphrams are well hidden away and it sounds like I need to systematically rip the whole dashboard underneath to pieces. Are there any known weaknesses that I can look for first?

All this is making my carb tuning unreliable, because effectively I always have a slow air leak into the manifold.

Regards

JohnH

I mention this with a note of caution since I've only done this in the engine compartment and not in the cab.
With the engine at idle, spray some either or brake parts cleaner at the hoses and listen for the idle speed to go up.

The ether gets sucked into the vacuum leak and changes your fuel air mixture momentarily, and lets you know about where the leak is.

Be very carefull doing this though because it can make you a candidate for the Darwin Awards.
--
'70 145, Webber converson, trying to keep it stock other than that.