This is my first power brake job. I am installing a master cylinder to a power brake booster. On the back part that bolts to the booster, there is a small screw with a small triangular metal piece that looks to be holding the push rod inside of the master cylinder.

Just wanted to double check that this should be removed and if there are any other steps I should take prior to installation?

Thanks!

no, do not remove that.
THat prevents the piston from being pulled out completely from the mc.
You would pull that to rebuild it.

Well it's a good thing I asked! Anything else I should do or know before installing this?

Thanks.

most aftermarket booters have an adjustible rod at the end. you need to make sure it is adjusted properly.
Basically I look in the master cylinder. You can see the piston in the hole in the bottom.
I make sure that when I press it up to the booster, I don't see the piston move.

So you will have to adjust it to where you see the piston move, then screw it back in a little at a time, till you stop seeing the piston move when you press it flat. Then just a little more and lock it down.

Booster rod instructions