Did you compare the pushrod length?
If the new one is slightly longer, that could be it. Grind a bit off the end if so. (Or use the old one).
You should be able to feel a bit of slack in the pedal and pushrod. if it feels tight,as I suspect it will, the pushrod may be a tad too long.
When I said does it come off OK, I meant does it release OK.
