DIY brake pressure bleeder
difficulty: 1/5
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Introduction

The recommended method of bleeding the brakes in the VW service manual is to bleed them under pressure.  You can buy one or you can make your own.  First, always use new parts because you don't want to mix chemicals in the bleeder.  Be careful when working with brake fluid - keep it off the paint because it will quickly eat your paint.  Like most pressure bleeders, this will fill the master cylinder reservoir to the top, so just vent the sprayer tank once you've reached the correct level and remove any extra with a turkey baster - one that will not be used again for food of course!

Here are pictures of what you are making:  It can cost about $50-100 less than a retail brake bleeder with similar functionality.  Note that these are not professional pressure brake bleeders, nor are the ones you can buy for $100.  Professional pressure brake bleeders use a diaphragm to separate the pressure and the brake fluid.  This keeps air and moisture from being forced into the clean fluid.  Because I already have a vacuum pump and I don't like the idea of tiny amounts of air put into the fluid, I just stick with a vacuum pump and have a helper pour clean fluid into the reservoir.  The tiny bit of air should not make any noticeable difference and is not visible to the naked eye but it's there.

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Parts

1 gallon sprayer
Hose Barb Adapter
Pipe Bushing 
10' of 3/8" vinyl clear tubing 
ATE N3030-33314 brake master cylinder cap (pictured below)- fits VW and some other euro cars
small washers and o rings

Procedure

Take the master cylinder cap and toss the inner cap.  Drill a hole in it and put your hose barb in there.

You don't want to crush the o-ring, just snug it on.  Over tightened o-rings are a main cause of twisted and pinched o-rings and leaks.  

Snip off the end of the sprayer wand and clamp the vinyl hose to both ends.  

Optional:  attach a bike valve to use an air compressor for pressurizing the sprayer or to check the pressure.  Recommended pressure is 10-30 psi, anything more could damage the brake master cylinder seals or encourage a loose hose to pop off and spray brake fluid everywhere. 

Enjoy!  Just make sure to not over pressurize the sprayer and to relieve the pressure from the sprayer slowly.  As always, wear safety glasses and follow all precautions in your factory service manual.  Remove any excess fluid in the master cylinder reservoir with a turkey baster when you are done.

pics and info from:

 faculty.ccp.edu/faculty/dreed/campingart/jettatech/bleeder/index.htm, bmw-m.net/TechProc/bleeder.htm