My brakes often lose pressure and sink to the floor, I've checked for leak and checked the booster check valve. My next step was to replace the Master Cylinder. The master cylinder removal QUICKLY became a huge problem lol, it's stuck pretty hard. So to make access a bit easier, I removed the fuse box and fuse box holder assembly which in turn reveiled the topside of the ABS unit. This vehicle has 2 wheel ABS, there are 2 brake lines on one side of the unit, but on the top side of the unit...there is a place for a brake line to go, but no brake line, just a threaded hole! Is this supposed to be empty? In the picture below, you can see the 2 lines entering on the side and the empty threaded hole on the top.

 

Is the hole dirty? I don't see any evidence of fluid on top there..... does it actually GO anywhere??

 

It's hard to tell, it goes in at least a full inch, can't get a good view without bending the lines.

 

Think I would just swap out the m/c, bleed the brakes really well, and see what ya get.

 

Yeah, that is the plan, I just happen to notice this and got curious. Unfortunately the master cylinder REFUSES to come off! I think I'm going to have to carefully cut the mount loabs of the the master cylinder and twist it off with a pipe wrench :-/.

 

It really shouldn't take that much effort...... are you sure you got all the mounting bolts out? Might hit it with some PB-Blaster, and rap on it lightly with a hammer.... See if it wants to let go.

 

Yeah, 2 nuts, 2 brake lines...won't budge :-/.

 

Chemicals, and a hammer...... Don't wail on it though. Worst case, hammer and chisel.