I now have a hand vac pump/tester and plan on troubleshooting today. It is plain to see that just the vac gauge is not going to be sufficient for troubleshooting this. Thanks for you two providing more infomation. I did a search and now have lots of info to go on. I have already poked around and made a crude diagram of most of the lines and should be able to get to the bottom of this quickly. I have the sinking feeling that the vac pump is the culprit but I am hoping not. The locks are not working as you mentioned. This ought to be fun. Thanks again. This is the best MB information site that I have seen.