There's More Than One Way to Skin a Cap (Post # 138)

The basic Motive Products pressure tank
and feeder hose.  It can do a lot of other
jobs too, like fill your transmission.

If you can't get your brake system to bleed the normal way by pumping the pedal, maybe you can pressurize the reservoir and "force bleed" it.  This is the whole premise behind a variety of kits  made by Motive Products https://www.motiveproducts.com/products/0100-european-bleeder. Sounded good to me. Nothing else I tried worked, so what have I got to lose?  I also liked the idea that theoretically you could bleed your brake system by yourself.  Theoretically.

The idea is simple, and so is the equipment: a Nalgene pressure tank with a gauge that can be pumped up to 30 psi (more pressure than you need to do the job), a few feet of clear plastic tubing, and a variety of caps to fit various types of reservoirs.They even make a kit that includes a cap for "European vehicles with a 45 mm opening".  Because the Girling tank opening measures 44.5 mm I thought maybe that's close enough.

The first problem was this breather nipple on
the underside of the cap.  A few drops of 
lacquer thinner dissolved the adhesive  and it
came loose by itself.

So I ordered one.  I did not really expect any of the supplied caps to fit The Alfatross' 1950s vintage Girling reservoir, so I was not disappointed when they didn't.  The only question was what would it take to make it work?  Could the Girling cap be modified to take the feeder hose and be leak proof?  Only one way to find out! Fortunately, I had a spare Girling reservoir I could experiment with.  It turned out to be pretty easy to adapt the Girling cap to the basic Motive Products kit. The hardest part was patiently waiting for the adhesive to set.

As I write this, the cap is on the reservoir in the car and I have pressurized it. The pressure tank's volume is 2 liters, which is way more volume than the brake system needs.  It would have been helpful if the manufacturer had mentioned that even with 5 bottles of fluid in the tank it takes about 150 strokes to get the pressure up to 15 psi! 

The "power bleeder" does work and it can be done single-handed, but through no fault of its own, it did not cure the problem(s) The Alfatross is having.  More about that in the next post(s).

Now, with the nipple out of the way I could
drill through the cap from the inside and screw
on this nylon hose barb fitting.  

A generous amount of my favorite all-purpose
adhesive, E-6000, made it an airtight seal.

At this point the cap was reunited with the
reservoir and pressure tested before being
filled with brake fluid.

The center of the original rubber cap seal had
to be removed to accommodate the end of the
hose barb.

The right-angle hose barb seemed like a good
idea at the time because there is very little
clearance between the top of the cap and the
body, but it made removing and reinstalling
 the cap very clumsy.  Of course this cap is  just
 for "power bleeding".  The original goes back 
on for normal service.