Gen1 ABS Accumulator Help

I'm rebuilding my abs unit with warrens rebuild kit and everything is going fine until I came to the accumulator. The reason I was rebuilding the abs in the first place is because it would squeal just when you start to drive/pull off from stationary and run every so often. Another thing I noticed was when I went to relieve pressure from the unit little to no fluid came out. The unit is supposed to be pressurized to around 2,000 PSI. I hear the unit run occasionally so its either 1 or 2 things. 1 the accumulator is bad and when the abs runs it isn't building pressure or 2 there is a leak somewhere. I've read to check the bladder of the accumulator and here is were I ask for primes help. The allen key seems to go really deep inside the accumulator not sure if this means the bladder is broken?

View attachment 143971
View attachment 143970

If you had almost no pressure when you relieved the system, it's almost certainly a bad accumulator. Too late to check now, but when it was assembled you could have jumped the pump relay (http://www.nsxprime.com/forum/showt...nergizing-Exercising-on-1st-GEN-ABS-Modulator) and observed how long it took to pressurize the system. Fast pressurization = bad accumulator because it's rapidly pressurizing only fluid. Pressurizing against the nitrogen on the other side of the bladder takes longer. Your accumulator could either be ruptured or have lost pressure. If it's ruptured it's basically non-repairable. But there's a guy who is repressurizing accumulators for Audis and some other makes (https://sites.google.com/site/audicqturbo/audibomb). I contacted him and he said he could do the NSX accumulator. Luckily I found a good used one to fix mine, but they're getting hard to find and most people want to sell the whole ABS unit (I bought a complete unit to get the accumulator). The new part is $$$.

PS: Forgot one thing. Pull the pressure relief plug on the accumulator, and if there's brake fluid on that side of the diaphragm, it's shot.

Having just replaced a bad accumulator on my '91, I'll provide a few more details. Story starts with changing all fluids in prep for the ride to the LV Westfest. All went well until the ABS flush. No brake fluid rose in the T-bleeder reservoir suggesting a bad accumulator. The first hint of trouble was that the ABS pump would run briefly, and then squeal to a stop, every time a started the car after sitting for a few days. I did have ABS pulsing on a a skid/stop, but in retrospect, perhaps not as strong a pulsing as before. Further, the ABS warning light never lit in the instrument panel. All this was not the case when I had one or more stuck solenoids in the first few years after purchasing the car new in '91. So my suspicisions were not sufficiently aroused to check further...until Westfest.

About 5 years ago I replaced the original '91 modulator with a '97 unit I bought from my neighbor Drew--prolific poster on Prime before he sold his NSX and moved to New Zealand--who had purchased the "97 unit off of Ebay. That unit had been in a wreck damaging some of the wiring/connectors. In particular, the pressure sensor wires were severed, so I just used the old (but still good) '91 pressure sensor/accumulator subassembly with the '97 modulator. Hence, I now had a presumably good '97 accumulator to replace a presumably bad '91 accumulator. But first I had to verify which was good and which was bad.

The attached images are of the two accumulators on my work bench using RE<<1's allen key test on the just removed '91, followed by the same key inserted in to the '97. Voila! The '91 pressure sensor tested fine for continuity, so I put it all back using the '97 accumulator and all works well. Almost never hear the pump run and ABS pulsing is strong.

Out...

Spyder