I just got my vacuum pump off and mostly rebuilt.... Looks like one of the check valves actually sort of "ruptured" and there were parts of it on the inside top (away from the block) of the pump. Also, a spring was stuck in one of the still good check valves.
The reason I am posting though, is that there is a 4th valve that wasn't included in the kit, and a lot of extra parts.
in the threaded connector on the pump (where it connects to the pipe) there was another check valve which was not functioning. I went ahead and pulled it out, and tested the pump by blowing into the threaded part. It does let me blow air, and it holds a seal. Do I need to worry about this 4th check valve?
Here is what's left of the check valve that goes in the fitting
http://i102.photobucket.com/albums/m112/EvenYourMomHatesYou/102_2929.jpg
For fun here is the picture of the check valve that broke the camel's back
http://i102.photobucket.com/albums/m112/EvenYourMomHatesYou/102_2931.jpg
Also, here is a picture of the spare parts. I assume they are just for other models of pumps...
http://i102.photobucket.com/albums/m112/EvenYourMomHatesYou/102_2932.jpg
The flat seal is the one I would have used, but mine looked and felt like metal, and I couldn't figure out how I would get it off, so I left it. I am not sure if the o-ring might go underneath that or what. and the hollow threaded thing... I have no clue.
Please advise before I throw this thing back on the car!
John