Accumulator leaks are pretty common on the GMT900 rides. The older hydrobooster with small accumulators didn’t leak much but once they started installing that big honk’n 6” accumulator the leaks started showing up more often.
You can poney up $466 and get a complete hydrobooster from Napa or remove the accumulator and replace the $2 o-ring. Just be careful because if that accumulator gets away from you, it will shot out like a 50 caliber bullet. You could shot your eye out like a Red Ryder bb gun!
GM dealers should service the o-ring by itelf without needing to replace the accumulator. It is a pretty easy job with a big C-clamp and the accumulator safety retainer too. You can borrow, rent, or steal the accumulator removal tool from a GM dealer buddy, or make one. It wouldn't be hard to make something up like the GM tool.
Tools Required: J 26889 Accumulator Piston Compressor
Removal Procedure
Caution: The accumulator contains compressed gas. Always use the proper tools and follow the recommended procedures or personal injury may result. Do not apply heat to accumulator. Do not attempt to repair an inoperative accumulator. Always replace an inoperative accumulator with a new one. Dispose of an inoperative accumulator by drilling a 1.5 mm (1/16 in) diameter hole through the end of the accumulator can, opposite the O-ring.
Caution: Push rod removal is not recommended. Improper staking of the push rod to the Hydroboost reaction piston can result in a loss of brakes. If the rod or seals require service, the entire unit must be replaced.
1) Apply the park brake and block the wheels.
2) Depress brake pedal at least 10 times in order to relieve pressure in the accumulator. Do this 100 times just to make sure the pressure is released!
3) Remove the master cylinder from the hydraulic booster. Refer to Master Cylinder Replacement.
4) Place the J 26889 over the end of the accumulator.
5) Install the nut on the stud.
6) Depress the accumulator with a C-clamp. If the accumulator does not move with moderate pressure, remove the C-clamp and depress the brake pedal ten times in order to relieve pressure in the accumulator.
7) Rotate the retaining ring (2) until either end of the ring is under the access hole (1).
8) Depress and hold the retaining ring (2) with a small tool inserted into the access hole (1).
9) Remove the accumulator retainer ring (1) using a small hook shaped tool.
10) Release the C-clamp.
11) Remove the nut from the stud.
12) Remove the J 26889.
13) Remove the accumulator (2) and the O-ring seal (3).
Installation Procedure
1) Lubricate all of the seals and the metal friction points with power steering fluid.
2) Install the accumulator (2) and the O-ring seal (3).
3) Place the J 26889 over the end of the accumulator.
4) Install the nut on the stud.
5) Depress the accumulator with a C-clamp.
6) Install the accumulator retainer ring (1).
7) Release the C-clamp.
8) Remove the nut from the stud.
9) Remove the J 26889.
10) Install the master cylinder to the hydraulic booster. Refer to Master Cylinder Replacement.
11) Release the park brake and unblock the wheels.
Yes, there should be room to move the M/C out of the way. Take a good look at make sure there isn't a hose o-ring leaking instead. Those happen too but accumulator leaks are the bigger problem on these late model rigs.
They are not hard to tear into. Heck, for the cost of the complete o-ring set mentioned in the Dirtymax forum you might as well just replace them all including the accumulator o-ring. As I mentioned before, more times than not, leaks on these later model hydroboosters come from a leak at the accumulator o-ring.
