There is just a one way valve at the brake booster. Some of the newer minivans had a small resevour built into this valve (93-95) When ever I'm in the wreckers I pick a few up no reason you can't use two of these in a row
some of these cars had a 1 way check valve inside the car right where the vacuum feed comes thru the firewall to the left side of the heater box. it looiks like a little white plastic barrel about 3/4" diameter. i know my 87 turbo baron with digital climate control does, and my 88 shelby Z with regular heater and a/c controls has the same part in the same place too. either way you want to check for leaks hope this helps mat -----------------------REMOVE-FOOTER-WHEN-REPLYING---------------------------- Questions? Visit http://www.sdml.org/ To be removed, visit http://www.sdml.org/pages/leave.html
