vacuum modulator, how do i know if it's working

[w123jab]

i have a very jerky gearchange, following a search and info on this forum i have checked my vacuum modulator.

the pipe was connected and there is a vacuum being created. but how do i know if this is the right pressure vacuum?

is it supposed to suck the skin off your fingers? or gently tease the hairs on your hand?

i would describe the 'suck' i got as being strong enough to pick up a sweet wrapper but not much more.

is this too weak to work the gearchange?

if so, can modulators be removed and fixed or do i have to source a new/second hand one.

i am determined to save this old girl, but boy is she testing me.

thanking you in advance as always for your generous help.

regards

justin

[ctaylor738]

Why not hook a vacuum guage up to the pipe and see what you get? I believe that your car has a straight-through connection to manifold vacuum, so you should be seeing around 15-18" at idle.

Use a vacuum source and gauge. Pump it up to 15 pounds or so and see that it does not leak off. If it needs to be replaced, it's not that expensive and very easy to replace.

Good luck,

[w123jab]

thanks guys,

i still have my old '82 200T, and i was thinking about taking the modulator off this and swapping it over to see what happened. does anyone know if the modulators are the same?


we're currently experiencing tropical amounts of rainfall in london, so my attention has been drawn to the leaking sunroof, which i discovered yesterday when i found half and inch of water inside the car!

old cars, don't you just love em!

regards

justin