what could it be? 91 ranger 3.0 auto problems

[pixiepooh]

When you shift from park to either reverse or o/d or drive or 1 or 2 it doesn't engage for at least a minute or soo. Once you get going in drive and come to stop sign and press brake peddle it jumps out of drive into a temporary neutral then after shifting back and forth in the 12Dand o/d it will go until next time you have to brake. I checked tranny fluid and topped it off. Will I be able to fix myself or is it totally gone. I thought I might drop tranny pan and put new filter in and fill it up again. Do you think this will fix or do you think it needs a major overhaul.

 

[Earl43P]

Make sure the vacuum modulator on the PS of the trans is getting a good vacuum.

Brake booster uses vacuum and so does your A4LD. It should be a hard line with a short rubber tube connecting to the Modulator.