Look at page 24-57 of your manual, and pay particular attention to Figure 14 and the associated text. I think this will explain how to test the check valves. The 3 armed valve apparently is missing one of the arms shown on the left side of Figure 14, so you can just ignore it for test purposes. The symptoms of a failed valve are covered in the last paragraph which starts on page 24-56. This refers to Figure 13, which also shows the position and purpose of each of the check valves. To respond to a particular member, you should be able to find the e-mail address buried in the text of the message of interest. I'm not on digest mode, so perhaps it doesn't show there, but it's easy for you to change to normal mode. Dick Benjamin ----- Original Message ----- From: Dennis & Mary Ann Martin <marti595@xxxxxxxxxxxxx> To: <mailing-list@xxxxxxxxxxxxxxxx> Sent: Tuesday, August 27, 2002 9:03 PM Subject: IML: Checking vacuum operated valves (Was: Auto-Temp help needed) I don't know how to reply to a specific message in a digest, all messages have the same (imperial club) address on them. Oh well, this is for Dick Benjamin who was good enough to reply to my question about vacuum valve testing. There are four "vacuum check valves" in the 1968-etc. Auto Temp system. It would be nice if they were simple in and out valves as you describe. Actually, there is one valve with three hoses connected to it, and three valves with four hoses. The hose connections are arranged with two on one side and two on the other, except for the "odd fellow", one of his is missing. I have not had experience with check valves with more than two ports. Each valve has an arrow on it which points perpendicular to the hose connections. Perhaps I need to remove each valve from the system and experiment until I can determine that one of the ports is where the vacuum source connects, and the others should trap vacuum if the source is removed? Please advise. Thanks, Dennis