4l80e line pressure
My 4l80e died out on me after 600 miles. My line pressure is:
120 idle
205 reverse
1-4 gears cruizing 90-120
typically when downshifting to 2nd and doing wide open throttle it's at 90psi and stays at 90psi and slips.
Obviously my transmission pump is out and or the valve body needs some attention.
If need be i can upload a video of the gauge readings
setup: 4l8i0e, manual valve body, forward pattern pull back to downshift, locking converter, stage 3 transgo.
I wasn't 100% happy with my transgo kit at first due to slow 2-3 shifts, but it has held up to several dyno pulls in 3rd with the converter locked, plus 2000 miles on the street, so I don't think it is fair to blame the design of the kit. I did a DIY rebuild, my first 4l80e, so it doesn't require a pro, just need to be careful and check everything twice. I bet my slow 2-3 shift is because I set up a clutch pack too loose, not because of a fault in the design of the transgo-3 kit. I will say that the instructions in the kit are not really very clear, especially if you don't build transmissions for a living.
The vacuum modulator is inside the pan, looks just like one from a th400, but the end is machined off shorter. I assume from your post you didn't do the work yourself, if so perhaps you should take it back to the people who did the work.
i had low pressure with the man. kit, when i switched out to an auto v/b
and compushift controller, i had much better pressure







