Anyone have any idea why I can't get this pin out that connects the rear brake arm to the threaded arm of the master cylinder?

I removed the cotter pin and assumed the pin would just easily push out. I've soaked it in PB Blaster, tried squeezing it with vice grips, hitting it with a hammer - no luck.

 

When I'm faced w/ a situation like this, I get a loose socket that is large enough for the head of the pin to fit in (looks like a fairly small one, like 3/8" would work here), and a pistol-grip type clamp (a C- clamp would also work).
Stack the socket on the head side of the pin (w/ the large opening towards the brake arm), and then tighten the clamp against the face of the socket and the tip pf the pin. It should shoot the pin out of the arm and into the socket.

 

Or, you might try and hold a hammerhead or other heavy object on the socket, and then strike the other end of the pin.

 

Yeah, I agree with all of this but I saw a video on YouTube where the guy literally just pushed this pin out with the tip of his finger. I really just wanted to make sure I wasn't doing something obviously wrong before I resorted to options like this...?

 

I would try the socket/C-clamp method mentioned above first.
Then if you can't get that to work, you might try applying some heat
on the side with the head...

good luck,

T.

 

Galvanic corrosion. Aluminum brake arm and likely a steel or stainless-steel pin.

heat and beat, more PD blaster or other type penetrant, or I like the clamp idea.

 

Use a small C clamp and a socket to push it out. Like 07 says above. That's how I did it. Mine was stuck the same way as yours.

John

 

And then run some Emory cloth/steel wool/fine sandpaper around that pin to clean up the surface and apply a coat of anti-seize to it before reassembling it.

 

This is what steel pin punches are for. 5 bucks at Ace harware. Tap it right out. Yes it should come out on its own with litle force but grit, grime, and corrosion usually hinder that from happening.