Hello,
1995 Lumina 3.1L LS
Just this morning when backing out to leave for work, the brake pedal went nearly all the way to the floor in combination w/ a "swish" sound as I pushed it to shift from Park to Reverse. I then shifted to Neutral and could feel the brakes loosing vacuum and had to push the pedal down further, and the idle also briefly revved up to ~1200 RPM. A couple weeks ago I replaced the front brakes along w/ new calipers and lines, so I put the car in park and checked the brake fluid level and it was at the same level as when I topped it off after the brake job. I got back in and drove down the road and the brakes continued to function properly as the day before without any feeling of losing vacuum, so I thought all was good.
However, as I approached 45mph, it would no longer shift to 4th gear. I have read several past threads on here and other forums, and I understand 3/4 going out is a common problem. That said, I was hoping that based on my experiences described above that someone can possibly help provide insight as to whether this most likely indicates an internal transmission problem requiring it to be pulled or something less evasive.
Thanks for your help.