Exactly, I questioned the tranny guy on that myself, it had a plugged off modulator on it when it went to him the second time, but when I got it back this last time he had put an old one in . I asked and he told me it was for a little back pressure????? no vac line gets hooked to it. It's a forward manual body. Right now it's still in my truck I haven't had time to mess with it too much and I'm a little disgusted( not lost interest) just disgusted. I WILL get to the bottom of this deal but looks like I'm going to learn automatic transmissions now. What would cause the pressure to jump so bad just in reverse on the jack stands at any rpm. The pressure would jump from way less than 150 to over 230.In the forward gears was around 190 and would drop at shift and return to the same reading inthe next gear, the whole back of the truck would jump at shift too. I don't have room in my driveway to get it to shift and I've already met with all the local deputies from my last blast down the public road, so I guess I'll fix my leak and go T&T maybe it won't eat itself up again????