d.delano
I've got about four ALDA's sitting on the shelf, three of which are unmolested. When I was playing around with it on the SD I swapped them out until I got the one that produced the most power right off the line. You will need a 27 mm (I think that is right) open end wrench. Get on the big nut underneath the ALDA and turn the nut clockwise looking down on the ALDA while holding the ALDA in place. You will then be able to remove it. It does not need to be very tight when you re-install it but you will want to inspect the gasket to insure a good seal.
You can purchase a brand new ALDA from a Bosch authorized facility but they are over $300
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