We had a leak from the B2 cover of my 722.315 transmission (1985 300D) and, when we had the B2 cover off, we saw we had the old-style piston, We replaced the B2 piston with the new style (1072700432) and at the same time replaced the outer O-ring (005 997 70 48), plastic bushing (126 277 08 50) and lip seal (006 997 73 47). With the job done, the transmission feels no different (it felt fine before) but we have a terrible leak from the B2 cover now....much worse than before.
- I am sure we got the rod in the B2 brake band, but I am wondering if I should have replaced the rod itself. Is the length of the rod the same between the old-style B2 piston and the new style?
- Am I correct in assuming the problem has to be an issue with the outer O-ring seal against the B2 cover?
- How does the cover seal against the ring? Does the piston push against anything in any way to help with the seal or is it completely unrelated?
- I'm pretty sure we got the lip seal oriented correctly. As we recall, one side is an open groove and the other side is flat. Which side goes toward the inside of the transmission? Is there any chance this could be related to the leak? What symptoms would we see if we got this wrong?
- I'm quite convinced I am seeing fluid collecting at the bottom of the B2 cover with the car stationary and running, but I am wondering if there is any chance that the leak could be from somewhere else and collecting on the cover? Looking at transmission diagrams I see only a vent at the top of the transmission above the cover but maybe I'm not considering something? The leak exists even when the transmission fluid is so low that it won't even register on the dip stick (yes I wish I didn't know that) so I know it's not a matter of over-filling.
Thanks in advance for your help/advice.
-John
01-09-2013, 06:38 PM
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