There seems to be a little misconception in the thread here. I would just like to add a little of what I have learned in disecting our ABS system.
1. The T-Handle bleeder is not the end answer. It was designed to be used to determine if the accumulator had failed, by measuring the amount of fluid that is being stored under pressure in the system. If you look at Pg 19-62 in the maintenance manual. (If you don't have a copy of a manual you can down load it here on Prime,
http://www.nsxprime.com/FAQ/Reference/1991_svcman/1991servman.pdf and download a copy. IT IS INVALUABLE!!!!!!!!!!!
Now look at the picture (better than a 1000 words) as you can see the Maiantnenace Bleeder port is located at the pump. So pressurize the system, open the bleeder and the only fluid that you are getting out is between the accumulator and the bleed port. Remember brake fluid does not compress, air compresses. All of the fluid that is still in the modulator is still the old dirty, possibly aerated, fluid. If you haven't built a solenoid actuation kit as shown in the DIY that was produced by DanO (Thank-you again Dan) then you are not completely flushing your system and are bound to have problems with it again. This is not to say that if you do the DanO DIY method that you will never have a problem again.
I have taken what DanO has done and tried to add to it by not allowing the old dirty, aerated fluid from returinig into the pump. I believe that any air in the system is a major contributing factor to pump actuation.
Now, if you think that you have a bad accumulator you can still use the DanO method to determine the outcome. All you have to do is pressurize the system to full pressure and then activate a solenoid and measure the fluid that comes out of the solenoid. This can be done by accurately setting the fluid level in the reservoir with the car level, get the ABS pump to actuate(slick road: wet, sand etc.) and then return to the same level location, verify fluid level, and then acutate a solenoid until there is "Zero Pressure". As the fluid starts to fill the reservoir suck it out and put it into a measuring container. The wifes Pyrex measuring cups work great, or buy your own for the garage. You should get between 100 and 160cc of fluid. If you get less than that you have a bad accumulator. It will be quite evident if the accumulator is bad, you won't get much fluid at all.
The first step is to make sure that there is no air in the system. Otherwise your test may be eronious.
Remember that full operating pressure of this system is 5800 psi. The pump will actuate when the pressure drops to 2800 psi and then stops at 5800 psi. I have seen it go up to 6000 before it turns off. I think that is just the slow reaction from the signal from the pressure switch through the ABS computer, or just a slow pressure switch. If you have a seeping solenoid the pressure can bleed off rapidly or very slowly. Keep this in mind if you are trying to determine if you have a failed accumulator.
Brad