Air suspension leaks are no fun my first encounter was back in January 2018, when my car would seldomly start to sag in the rear, especially in the left side, I ignored it at first...however as months passed it become more and more apparent and frequent and now both sides are sagging, there was even damage to the side wheel flairs. So it was time to resolve this issue for good. Its best to rectify this problem asap, as leaving it unresolved in the long run may cause the air pump to burnout and or cause premature wear on suspension parts.
The culprit a 70k miles 4 yrs old air bellow looks like never towed never lifted heavy things and riding on 20 in oem rims, (left) when its not stretched it looks normal but (right) when you begin compress the bellow and stretch it the walls problems begin to show multiple deep cracks on the rubber bellow, this is the reason why air leaks occurs.
***DISCLAIMER***THIS IS AN DIY COMMUNITY GUIDE I'M NOT A PROFESSIONAL AND WILL NOT BE HELD RESPONSIBLE FOR INJURY/DEATH OR PROPERTY DAMAGE BY FOLLOWING THIS GUIDE, IF UNSURE SEEK PROFESSIONAL ADVICE/MECHANIC, OTHERWISE PERFORM AT YOUR OWN RISK
***DISCLAIMER***
Tools
Battery charger
ISTA-D
Pair of Air struts ( I got mine at Arnott $160~ +shipping/each)
10mm Wrench
17 socket
Various ratchet and breaker bar
1)
USE SAFETY!!! ALWAYS USE JACK STANDS TO SUPPORT YOUR VEHICLE, ALSO USE A WHEEL CHOKE ON BOTH FRONT WHEELS, OR CAR WILL ROLL FORWARD WHEN LIFTING!!!!!
Lift up the vehicle you can use the rear axle as jacking point (#3), do not jack up with out something in between the axle and the jack pad (i use a block of wood to prevent marring on the diffrential)
2) After lifting and using appropriate support remove wheel, use 17mm socket, I use a torque multiplier makes things a breeze to remove those lug bolt.
3)After removing the wheel you should be able to see the air strut
4) Now its the time turn on the ignition, hook up your ISTA-D and your battery charger so your vehicle don't go to sleep and you ending up having to start over.
5a) Next before we begin to deflate the strut with ISTA-D, you'll need to remove the fuse for the air pump (Per "ISTA-D") go to the back fuse box (located in the right side panel in trunk) and find 40 amp fuse
#110 (see yellow square)
5b) If you look at the fuse chart it says air suspension fuse #110 and #135 and you accidentally pulled fuse #135 (5 amp) you will get this nice little warning, don't worry, just turn off the ignition put the fuse back in and turn on the ignition back and you'll be good to go. I didn't know better OOPS
6a) Once you pulled the fuse its time to deflate with ISTA-D.
Go to VEHICLE MANAGEMENT>SERVICE FUNCTION>+Electronic Ride Height Control > Filling and Discharging air from air bellows > ABL Electronic ride height control (EHC) Filling and draining
6b) Next prompt it ask you if your bleeding or filling. Select Bleed of the air bellows (bottom)
6c) Next prompt, Make sure you've done the precondition check list, failure to do so will cause it to stop and you'll have to redo. Click Yes when ready. NOTE: You'll have 3 consecutive cycles before it automatically invoke a 5 min cool down of the release valve relay, it make take more then 1 cycle to deflate completely (it took me 2 cycles)
6d) Next Prompt, The air suspension will cycle the release valve and both sides will drain NOTE: NEVER LET DOWN THE VEHICLE IN DEFLATE STATE OR DAMAGE TO SUSPENSION WILL OCCUR!
7) You should be able to observe the strut contracting/deflating, also squeeze the strut bellow it should have a soft sponge like consistency, if it difficult to squeeze another deflate cycle is needed.
8) Removing the air strut, first thing is you'll need to remove the bottom squeeze tabs, a channel lock pliers or a screw drive to squeeze in the squeeze tabs, and remove from its mounting socket.
9) The bellow has 2 tabs on top that alined and twisted on to secure, to do so just rotate the entire bellow
counter-clockwise, it should not take much effort to do so (if deflated fully) and only about < 1/2 turn.
10) Next Remove the air line from the bellow, you'll need to rotate the the strut top side facing outside/you this can be a bit tricky but its not bad then use a 10 mm wrench to remove the nut from strut (the line is red because i forgot to take pic and was working on the other side))
11) Remove the air line harware, you may need to use a screwdriver to pry the brass line holder/seal, check line for damage, clean and set aside.
13) Remove the strut,
OBJECTIVE NOTE arnott is diffrent from OEM in terms of the TOP part, it has a larger top clamp and the top metal clamp is exposed, vs the OEM with smaller top with the clamp recessed into the rubber bellow fold,
14) Next you'll need to swap over the dust cap from the oem to the new one, be sure you align the air line hole on the dust cover to the strut bellow.
15) Insert air line, besure to push in as far in or up to the white line, mine been arnott has a gap on the white line, i could not push in further.
16) Installation and secure, with the air line installed you have to wrestle it in it can be tricky but it's doable, start with the top part facing you, slide it in and slowly rotate the up right just watch out for the air line make sure its not kinked or twisted up. After its up right, you'll need to alight with the tabs by feel, just slowly rotate the bellow with slight upward trust and it should plop right in when you've aligned tabs correctly then slowly/gentely turn the bellow clockwise further more until it stops, and finally pull the bottom bellow down to its securing socket till it clicks and stays in place it may take some grunt to pull it down.
17) Check the air line and make sure it secure to its clips and make sure its not obstructing or kinked, Reinstall the wheel and torque lug bolts to 105 lb/ft and repeat steps 3 & 7-16 for the other side. DO NOT LET THE JACK DOWN WITHOUT REFILLING THE BELLOWS WITH AIR, SUSPENSION DAMAGE WILL OCCUR!
18) After completing the other side, reinstall fuse
#110 40 amp
19) In ISTA-D, if you're still in the Bleed option, it will prompt you to perform another bleed, Select
No
19b) In ISTA-D Go to VEHICLE MANAGEMENT>SERVICE FUNCTION>+Electronic Ride Height Control > Filling and Discharging air from air bellows > ABL Electronic ride height control (EHC) Filling and draining
19c) Next prompt ask you for Bleed or Fill, select Fill (top)
19d) Next prompt, there will a prerequisite checklist before performing fill function, check yes and hit continue when ready.
19e) Next Prompt, the ISTA-D will fill up the air bellow till it has reached maximum pressure will take about 20-30 seconds, once finished there will be "End of service function" hit close and that's it for ISTA-D
20) Slowly lower the vehicle and you're done, now it make take a while for it to settle down, a quick drive and it will come down to normal height and you'll never have to deal with any more saggy rear ends!!!
