Home made brake pedal depressor tool.

[David Pozzi]

If you slightly depress the brake pedal, fluid won't leak out when you disconnect a line.
Just take a strip of steel, 8" x 1.5" x 3x16". Bore a hole in one end that is 1/8" larger than the broomstick. I used 1" hole for a 3/4" broomstick. Don't deburr the hole too much, just enough so you won't get cuts. A wood stick works best. You can put a rubber crutch tip on to get a better bite on the brake pedal.

[NOT A TA]

I've used a similar setup for my cars to do one man pump bleeding. I cut a stick the correct length for fully depressed brake pedal to the steering wheel. Firebird one doubles as the trunk prop since I don't have trunk springs for a spoiler car. I like your adjustable version!

[Gratefuldiver]

So when I swap rear calipers this coming week I can avoid losing fluid by pressing the brake just a little? How does that work?

[TheBandit]

Not sure how I stumbled on this post, but that's a great and very simple idea!

So when I swap rear calipers this coming week I can avoid losing fluid by pressing the brake just a little? How does that work?

The piston inside the master will move past the compensating port on the master, so the master is effectively blocked off so the piston can build pressure to the brakes. This is a normal part of the operation of the brake master cylinder. If you push it just a little ways it will block the compensating port without building much pressure. The broomstick holds the piston in that position, keeping the compensating port sealed off.