2002 Ford F150 - Transmission Flush FIXED

[dusylube]

I've got a 2002 F-150 Lightning in the shop and am trying to flush the trans fluid, I'm using the snap on trans flush machine. The fluid will fill but will not empty, any ideas?
I've tried switching lines and the transmission is nice and warm.

[wbuxton]

Does the machine have pressure gauges and if so what are they reading?

[VCAC239]

Are you in park or neutral???? Certain vehicles won't flow in park, some have to be in neutral & vice-versa.

Jeremy

[brianp87]

I know nothing about that machine I use a bg machine.

[dusylube]

I've got no pressure guages, but on further investigation we found that the line we've tapped into has got a check valve - changed to other line and problem solved. Thamks for the help everyone.