Set modulator pressure by feel?
 

Hoping to change modulator valve tonight on '89 560 SEL, but without access to my mechanic friend (he said it's some kind of holiday) so no pressure measuring equipment. From searching other posts, it seems possible to get this valve set pretty close by the feel of the shifts. Will taking that approach (until I can get an accurate reading and adjustment in a few days) cause much if any harm? Could it be worse than consuming a quart of fluid every 3 days?
Thanks for any input you can offer.
Earl McLain
'89 560 SEL

You cant hurt anything. I would set the new modulator to the mechanical mid point and go from there. Clockwise makes firmer shifts.

Is your fluid consumption a result of a leaky modulator??

Thanks for your reply Dave. Changed it last night, and after about 7 test drives got it pretty good. The first shift-24mph-is a little soft, and the second-34mph-feels a little firm. I'm about a half-quart high on fluid and need to suction that before any more adjustment. It will be interesting to see how close I got to 55psi by trial and error.

I replaced the vacuum lines from the trans to the intake manifold and then there to the fire wall and no sign of fluid after about 40 miles of driving. The gasket is also leaking a bit, and it looked like there may be a leak at the kickdown solenoid. Wev'e had the car for less than 2 months, and it shows signs of sitting idle.

The shift points seem a little close together, so the next hunt will be for the Bowden cable and sheck the adjustments there. Thanks again for the information--you are the tranny guru.
Earl
1989 560 SEL