Installing all Infinity Q45a Suspension Accumulators

Q45a Suspension Accumulator Removal

THIS WORK IS COPYWRITED June, 2001 by Keith Bowers and may not be distributed or reproduced except with express written permission. B and B Suspension and author expressly denies any and all liability for any adverse consequences, injury, or loss resulting from reading, implementing, or applying any of the information contained herein.

Removing and Reinstalling Suspension Accumulators on the Infinity Q45a

Written as if all 9 are being removed.

1. Support the car on 4 jack-stands placed under the frame, one behind each front wheel, one in front of each rear wheel. These should each be rated at 2 tons.

2. Remove all four tires. Store the tires under the car. (Also provides something other than you for the car to fall on)

3. Remove the belly pan under the engine

4. Remove the right and left front fender well front shields. Most of the plastic panel fasteners have a plastic screw in the center, which are unscrewed, releasing the clip.

5. (This step is not necessary if only strut accumulators are being exchanged) Remove the rear fender well access panels inboard of the wheels, in front of the axle. Push in on the center of the plastic fasteners to release the ‘plug’, which allows the fastener to be removed.

6. Remove the plastic shield covering the right rear suspension valve under the trunk.

7. Remove the dust cover on the top of each front strut. Pry up around the edge of the retainer where it snaps into the metal ring.

8. On the front struts, connect a small plastic hose to the bleeder screw on top, (looks just like the ones on the brakes) routing the other end into a clean container. Carefully open the bleeder screw to release any hydraulic pressure. Lightly close the bleeder when all the pressure is released. Repeat on the other side on the front.

9. For the rear struts, the air bleeder is in front of the strut where the hydraulic line is bolted to the car frame. ( This step is not necessary if accumulators are only being exchanged) Attach the hose and bleed any pressure as for the front. Lightly re-close the bleeder. Repeat for the other side.

10. On the right front control valve, (in front of the right wheel) attach the hose to the bleeders and release any pressure as for the struts. Re-close lightly.

11. On the Right front control valve, locate the main pressure bleed screw, which is held with a lock nut. Loosen the lock nut and loosen the screw by turning it counterclockwise to release any system pressure. This screw is often very tight. Retighten the screws and lock nuts.

12. On the LEFT front control valve, locate the pressure bleed screw, held in place by a lock nut. This screw is often very tight. Loosen the nut and turn this valve IN to open. It is backward from the others IN to open, OUT to close. After the pressure is bled off. Turn it back out and lock in place.

13. On the right rear control valve bleeders, attach the hose and release any pressure as for the other valves. Re-close lightly

14. On the rear control valve, also locate the main pressure bleed screw(s), which is(are) held with a lock nut(s). This screw is often very tight. Loosen the lock nut(s) and loosen the screw(s) by turning it (out) counterclockwise to release any system pressure. Retighten the screw(s) and lock nut(s).

15. The strut accumulators are about the diameter of a can of cola and are held onto the strut assembly by three small bolts. The accumulator slips over a pipe and seals with an O-ring around the pipe, and also a flat rubber washer against the base plate to which it is bolted. The accumulator will probably be full of oil and this will spill out when it is removed. Put a catch pan under the strut. Do not try to save and reuse this oil as it is inevitable that dirt will fall off the strut into the oil. Carefully loosen the 3 bolts several turns and wiggle the accumulator before completely removing any of the bolts to insure there is no residual pressure. Finding none, remove the bolts and lift the accumulator straight up off its seat. Be sure and lift the accumulator straight up to avoid damaging the O-ring seal. Be careful not to lose the flat rubber washer. Replacements are not available from Infinity/Nissan. Keep them in a safe place, like wrapped in paper towel in the glove compartment. Do not try to remove the O-ring seals, leave them alone. The pipes can be plugged with twisted paper shop towels or some other non-shredding material to reduce any oil leakage. Duct tape over the stuffing to hold it in place. Do not use something that will leave trash in the system.

15. The rear valve accumulator is black and about 1 ˝ inch in diameter and about 4 to 5 inches long and usually points to the rear. It does not have anything attached to it. It screws into the valve assembly (standard right hand threads) and seals with an O-ring at the base of the threads. Simply grasp it with channel-locks or a pipe wrench and unscrew it. Do not mess with the O-ring seal.

16. The rear main accumulator is black, about 2 ˝ inches in diameter and 8 inches long, and has two hydraulic lines attached to the rear with banjo fittings. Loosen and remove both banjo fittings (they may be tight) before loosening the clamps holding the accumulator. Keep the banjo fitting bolts and seals in a safe place for re-installation. After removing the banjo fittings, loosen and remove the clamp bolts and stuff around the accumulator and slip it out. Remember it may be full of oil.

17. The front main accumulator is in the right front fender well, in front of the wheel opening, toward the outside. It is black, about 2 ˝ inches in diameter and about 10 inches long, mounted vertically. A hydraulic line is attached to the bottom with a banjo fitting as on the rear. Loosen and remove this before loosening the accumulator attachments. It is held in place by two small bolts through a tee assembly on the top of the accumulator.

18. The front valve accumulator is the same size as the rear one (1in in diameter, about like a big Polish sausage, but faces forward toward the coolant reservoir. There is enough clearance to remove the accumulator, but not re-install it after the recharge valve is added without making some temporary clearance. It is easier to remove the entire valve assembly or loosen/remove the coolant reservoir. Loosening the coolant reservoir is straight forward and probably the easiest thing to do.

To remove the valve assembly, simply loosen and disconnect the hydraulic lines from the valve assembly at the joints under the front end. These are flare joints and do not have sealing rings. Disconnect the electrical connection, remove the attaching bolts and lower the valve assembly out. Unscrew the accumulator. A drip pan is essential. Not much oil leaks out, but a little goes a long way.

19. The pump output balancing accumulator is located above the front frame in the center. Simply disconnect the hydraulic line and remove the bolts attaching the accumulator and its mounting plate to the frame. Then disconnect the electrical connector and slip the accumulator and mounting assembly out. Take note of how the mounting plate and assembly are arranged and bolted in place so you can reinstall it without pulling your hair out. It’s not difficult, just not as simple as the others are. When the unit is out, unbolt the accumulator from its mounting bracket. REMOVE the pressure switch by unscrewing it. DO NOT ship it with the switch attached. IT WILL BREAK. Keep it in a safe place for re-installation.

20. In all cases, re-installation is the reverse of removal. Nothing exotic or special. Just remember to put the sealing rings back in place. You should clean them off and lubricate them with some of the suspension fluid. Cleanliness is important. Do not get dirt or trash into your system!

21. After all the accumulators are re-installed, all the electrical connections reconnected, all the lines re-attached and tightened and checked, etc., you are ready to begin bleeding the system.

22. Fill the reservoir with new fluid (Get it from T.J at Scottsdale Infiniti). Initial air purging can be accomplished by pulling a good vacuum on the reservoir. However that is not essential. Start the car (it’s still up on jackstands.) Open all the pressure bled screws-- the ones with the lock nuts—each in turn starting from left front. Leave them all open for a couple of minutes to flush things out real well. This removes most of the air and any debris that may have gotten in. There is a real fine sintered metal filter in the sucton line to the pump. After all the pressure release screws have been re-tightened, then --- Go from one air bleeder fitting (these are the ones at the top of each strut) to the next with your rubber hose and clean container, bleeding out air until you get no more. Repeat the trip around the car once more to ensure good air bleeding. You should save and re-use this new clean fluid (provided you use a CLEAN container and do not let dirt fall into it. Remember to check and refill the reservoir frequently during the early stages. This may take 30-60 minutes to accomplish. Check for leaks anywhere while doing this.

23. After all the bleeding, shut it off, install new dust caps on the bleeders and put all the access panels back on, put on the wheels, remove the jack stands, check the fluid level and go driving. It is usual for it to make some funny sounds for a day or two if all the air has not been bled out. Don’t worry that is normal.