So my 140 is still valid if we current employer never void it?
-Not true. YOur I-140 sponsor has to agree to hire you back later and agree to support your green card application, then that I-140 is still valid. If the I-140 does not agree to do that, the approved I-140 is void when you leave the employer.
I
to another company and transfered my H1 to the new company,
can my new employer file 485 for me without having to go through 140 again?
-No.