Brake pedal goes to the floor,and master cylinder was just replaced

[mrmarkuSS]

I took it to another shop. That guy looked at it and called me back with then following:
Master cylinder is shot (apparently once the pedal goes to the floor after the fluid runs out like it did will cause it to go toast)
Pinhole leak in rear line feed (where I spotted the puddle of fluid on the frame/hold down clamp)
Left front brake line rubbing on upper control arm (replaced and rerouted and insulated with rubber so that won't happen again)
Left rear caliper bleeder screw was frozen (replaced caliper)
He got the frozen pin on the right side to budge (heated the hell out of it and sprayed PB Blaster on it)

He told me the other lines eventually will need replacing down the road because they are rusting in a couple of spots.

Looks like the problem is solved.

NADACOP,I'm going to get those pics done of the brake fluid cooler.

[NADACOP]

I would appreciate it but take your time! It sounds like you've been pretty busy.

[Terry #585]

I too want to see a picture of that brake fluid cooler.

Stay safe.

[Navy Lifer]

Originally Posted by mrmarkuSS

I took it to another shop. That guy looked at it and called me back with the following:

He got the frozen pin on the right side to budge (heated the hell out of it and sprayed PB Blaster on it)

Looks like the problem is solved.

Just "heating the hell out of it" and using some PB blaster doesn't fix it, and the heat would have destroyed what was left of the rubber boots that are intended to prevent moisture from getting into the pin bores (if anything was there in the first place).

Unless the caliper bracket and/or slide pins were replaced, new boots installed, and proper lubrication was used for the slide pins, the caliper "float" system problem is going to return in short order.

See items 2, 3, and 8 - not the best illustration, but you should get the idea.

OE parts info

18021519 - BRACKET, OE, caliper abutment for 9C1 (cad plated)

18021945 - BRACKET, OE, caliper abutment for Impala SS (black finish)

18038751 - HARDWARE KIT, CALIPER - H-clip, guide pin boots & bolts, 2 per car required, ACD Durastop

18022147 - PIN, caliper guide
12530698 - PIN, caliper guide substitute, C5 rear ACD 179-2011

14067552 - BOOT, caliper guide pin
12530703 - BOOT, caliper guide pin substitute, C5 rear ACD 179-2008

14067559 - BOLT, caliper guide pin
(has thread locker pre-applied)

12337902 - BOLT, caliper bracket to backing plate
(2 per bracket, has thread locker pre-applied)

Some of these parts are also available in the aftermarket:

Bracket - Cardone 14-1122

Slide pin discussion