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Tom109
05-28-2015, 10:48 AM
Found this from RN:

http://c7743.r43.cf2.rackcdn.com/Downloads/instructions/abs_brake_bleed_rrc.pdf

I'm about to install a new Accumulator, new fluid, and bleed the system.

Tom109
06-15-2015, 11:24 AM
In preparation to replace the accumulator last weekend, I compared the linked RN file above with the 1995 RRC WSM, and found quite a few steps missing. While the RN file shows how to bleed the calipers, it overlooks bleeding the accumulator, hydraulic pump, hydraulic boosters. It's not over complex procedure but it does have many steps, requires two people and almost 2 quarts of brake fluid. So I followed the WSM procedure.

Good news, I replaced the accumulator, bled the system, and have a 100% fully functioning, RRC/ABS/TC brake system!

Tom109
08-30-2015, 10:54 AM
About month after I replaced the accumulator and fully bled the system, I noticed on highway trips that the ABS pump cycled every 8-10 minutes with zero braking activity, and in-town-driving cycled the pump ~4-5 applications, and every time I pulled away from a stop. This didn't seem normal, so I replaced the two 12V relays that control the pump. No change.

After checking the entire system for leaks and proper operation, I decided to bleed the upper ABS system ( pump, accumulator, ETC and ABS blocks). This restored proper braking. I'm now back to 9-10 brake applications before the pump cycles. I have yet to test it on a long highway trip (to see if it cycles without brake application), but it appears there was a bubble or two left in the accumulator plumbing.

Tom109
11-09-2015, 09:56 PM
Long-term follow-up. The number of brake applications diminished back to ~4-5 before the ABS pump cycled. The pump also changed pitch as it was pumping, indicating air trapped in the upper system. I bled the whole system again per the WSM procedure, and again a few weeks later. I swapped relays and just could not resolve it.

Tonight, preparing for a test run after a transmission filter, fluid and cooler line service, I gave it one more bleed. This time I did something different. I only bled the pump and accumulator.

1. For the pump I simply opened the reservoir cap and then the pump bleed nipple, and let it ooze. First round I did catch one big bubble burp out. Subsequent round nothing.

2. For the Accumulator, the nipple is the highest, forward-most bleeder on the TC valve body. This time I bled as follows: - pedal-DOWN/nipple-open/key-ON-cycle-pump/key-OFF/nipple-close/Pedal-UP. A healthy dose of bubbles poured out! Did this a few more times until no bubbles were seen.

Back on the road with healthy brakes and no more air in the system!