Pump or bomb?

[AUDIDUDI@delphi.com]

My '87 5k has all the symptoms of a failed brake bomb but also has a reduced
amount of power assist for the steering, which suggests it might be the pump
instead.  I've read everything written about how to determine which is which
but I don't have access to a pressure gauge and wonder if there's some other
way I can narrow this down.  Given the price of the parts, I hate to get out
my credit card and just start ordering them willy-nilly ... equally, I would
rather not take the car to a shop for just a diagnosis since it's considered
to be poor form around these parts and I'd prefer to stay on good terms with
the people there.

Does anyone have any ideas how I can figure this out using just the tools in
my large Craftsman roll-around toolbox and/or a voltmeter?  Is the hydraulic
pressure switch for the auto-check system proportional (its output indicates
the pump pressure) or on/off (it only sends a signal when the pressure's too
low)?  Thanks for any input on this....

                /| | | |\  |   |\  | | |\  |  AudiDudi@delphi.com
               /-| | | | | | = | | | | | | |  Jeffrey Goggin
              /  | |_| |/  |   |/  |_| |/  |  Scottsdale, Arizona