DV guru's please read...When testing aftermarket Diverter Valves...
 

...I was told that one way you can test the operation of the valves (after DV is out of the car)is to push up on the piston with a pen or something and let it slide back and forth. Then push it all the way up and cover the nipple with your finger. The piston should stay up as long as the nipple is covered, correct?

I tested my hyperboost dv's while lubing them up yesterday (i was hearing a blow-off sound, but deeper than the one the stock blown DV's made, decided to lube and test to see if they were the cause). After they were all lubed up (using Mobil 1 synthetic grease) I pushed up on the piston and covered the nipple. It held vacuum because I heard the air go out after I let go, but the piston slid down a bit before I pulled my finger off. Is this normal?

vacuum test them. suck on the vacuum nipple and the piston should go up. if nothing happens, theyre
 

broken. when you release the vacuum (stop sucking), you should his the piston clunk closed.

Good thing you stuck the word "vacuum" in there :-)

lol, i wasnt going to, but then reread the post ;)

lol, bad enough you followed that with a "p" word . ;-)

We don't think dirty like you, we're all growed up :)

Ha, should have said your too young to be a dirty old man :-p

You're too young to be a dirty old man!

Piston slid down a bit until it built enough vacuum hold it up. ;)

you must have some suction power.. I need mityvac to lift it it off the seat