Classic/Antique Car Repair: Master Cylinder question..., chevrolet el camino, generic question

Question
Mr. Benjamin:
I'm not sure if you can help me with this or not...it's sort of a "generic" question, not really make or model specific.
I need to put a new master cylinder on a 1979 Chevrolet El Camino.  I've found several auto part websites that sell remanufactured master cylinders, but they all say that I will have to "bench bleed" it in order to install it correctly.
What exactly does that mean?
I'm a fair jack-leg mechanic, and I know you have
to be real careful not to get air in the brake
lines when you disconnect them.  I also know you
need to loosen the bleeder valve at the wheel and
pump some brake fluid through the lines just to be
sure.
Is "bench bleeding" something that needs special
tools, or would be beyond my abilities?
Any info, suggestions greatly appreciated.
Warm regards,
David Gardner
davidg32@yahoo.com

Answer
Bench bleeding is a process where you clamp the new master cylinder in a vise or other holding device, right side up, and screw short plastic hoses into each of the outlet fittings. Then you fill the master cylinder, both reservoirs, and pump the piston by pushing a rod into the back of the master cylinder until the hoses squirt clear clean liquid brake fluid and no air.   

You curl or hold the short plastic hoses back into the top of the reservoir so that you don't have fluid spilling all over the place.  

Then, once you have all the air purged out of the guts of the master cylinder (and the little hoses), you carefully, without spilling the fluid out of the reservoirs, take the new unit to the car and install it on the booster, then very quickly take each plastic hose fitting off and connect the car's brake lines to the fitting, trying not to spill or lose too much fluid from each of the lines.  

If you do this without losing more than a few ounces of fluid, you will not need to bleed the brake cylinders on the wheels, as the amount of air that you will have let into the lines will purge itself the first few times you step on the brake.  

This assumes that you haven't gotten a lot of air in the car's lines due to some other service operation - if that has happened, you will have to bleed the wheels also.

No special skills or tools are required. If you buy your replacement master cylinder from NAPA stores, it will come with the hoses and fittings for the bench bleeding operation.  Consider buying a new master cylinder, as it costs very little more than a rebuilt, and will last longer in service.

Dick