The useless manual is the Haynes one. It's usless more because it's so general and lacks any specifics, than because it applies to the W123. I had read this review about it many times here, but bought it anyways thinking it might have some worth. NOPE! When I replaced the ignition switch I spent a couple afternoons dismantling my dash looking for the "locking pin". The last step in the manual just says "push in locking pin and remove switch from column...." OK, what is a locking pin and where do I find it? No pictures, no nothing... This site (well actually a link to diesel giant) had a big long illustrated walkthrough. Found it in about 2 seconds.



I read through that post on vacuum testing a little more thoroughly and still can't find an exact answer for how to check if the transmission valve is bad. If I put a vacuum on it and it leaks does that mean it's bad? I just need to know if I should replace that valve.

While I'm at it, I had read that if you have oil in your lines, the diaphragm on the pump is bad. I disconnected the main line to the check valve and put a vacuum on it that held. I read somewhere that this means the diaphragm is good? Can someone clarify that, I'd hate to do a diaphragm replacement if it's unnecessary.