do you have a mityvac tool? If not get a hold of one. Harbor freight has a US general copy for about $25. You can then start to take readings on your vac lines and see if your trans is sufficient or has a leak somewhere, and work back wards from the mod fitting back to the vac source to see first if the line is leaking. If that's good, possibly adjust mod. "T" fitting. but read up on this stuff more. I'm just learning all about it myself with my son's 240.