Team MightyBoy

Hi again, still trying to fix all the issues on my new project and while I'm waiting for my new carburettor and fuel pump to arrive I thought I'd have a go at fixing the brakes.
I filled the brake fluid reservoir and proceeded to bleed the brakes. Front brakes no problem but no fluid pumped to the bleed nipple on the left rear (right rear has no bleed nipple). I followed the brake lines to the proportioning valve assembly just in front of the rear diff and removed it. I gently blew some compressed air into either end and it blew through no problems so that lead me to believe the master cylinder isn't creating enough pressure to push the fluid all the way down the back.
With everything all connected, if I pump the brake pedal it bubbles in the reservoir.
I started to undo all the steering column to get to the master cylinder behind it but it seems like I have to remove the whole bloody dash to get proper access to all the bolts to remove the master cylinder. Is that right?

Short answer, yes the dashboard needs to come out.

So the dash is super easy to get out and only took 35mins. Now that I'm looking at the brake master cylinder and booster, how do I test it to see what the problem is? Preferably I'd like to repair it with a kit for $100 rather than spend $400 on a new one.

If you can't get pedal pressure then the M/C seals are probably stuffed. Disassemble, hone/sleeve and rebuild.

Ok no worries. Thank you for always answering my questions. Without your help I'd be clueless and have probably sold the van when I don't want to.