Features

How to replace an air spring - pictures

by: Auto Express team

27 Sep 2017

Go to: How to replace an air spring

REMOVING THE AIR SPRING ASSEMBLY: With the air suspension system set onto extended profile, crack off the wheel nuts and chock all wheels which will remain in contact with the ground.
Insert an axle stand under the appropriate chassis leg. I used two for safety, but it can confuse the system on re-inflation later.
Jack up the front wheel, and remove the road wheel. We’ll need the jack to alter the axle height at various points of the job.
Locate the EAS diagnostic socket, which is under the driver’s seat behind a kick plate. Fire up the PC, or your diagnostic tool.
Open the software, plug in the diagnostic lead, and switch the ignition to position ‘II’ which puts power to the EAS Electronic Control Unit (ECU).
Establish a link to the vehicle via the software, and you should then hear the relays in the dashboard click, confirming it is successful.
The EAS Unlock Suite enables you to just depressurise the springs. A countdown timer tells you when it is done. Then turn off the ignition.
The vehicle will now be right down onto the bump stops at the rear, but the fronts will still hold some air, as they are raised off the bump stops.
To reduce any residual pressure, lower the axle a little, thus deflating the air spring. I painted my damper to illustrate the difference.
Wearing eye protection, use an 8 mm spanner to push on the air pipe collet, and release the air pipe. Be ready for residual air to be released.
Using a small, flat bladed screwdriver, prise out the spring retaining clips – there are two at the top, and two at the bottom.
Remove the air spring assembly by squeezing the rubber, lifting out the lower end, then carefully sliding the top down between the brake flexi hoses.
DETACHING THE OLD RUBBER SLEEVE: Holding the flange of the lower piston in a vice, prise the rubber sleeve off the piston using a tyre lever, without damaging the soft aluminium.
It will suddenly pop off. Note the small fitting lip on the edge of the piston. If you did damage this, you’ll need to source another one.
It is the same story at the opposite end to remove the top plate. Carefully lever off the edge of the rubber sleeve – a gentle pull will help.
Clean off any old rubber, road grime or dirt from both of the mounting faces. Inspect them carefully for damage that might prevent an airtight seal.
REBUILDING THE AIR SPRING ASSEMBLY: The new rubber sleeve is a tight fit. Silicone spray was used to lubricate it, but not too much to leave moisture in the air system later.
Start with the top plate, fitting the rubber sleeve on diagonally to start with. Carefully ease it fully on, rotating it a little, and it should pop on.
Before fitting the lower piston, make sure the mounting pegs are in line between top and bottom. Place some marks on the rubber sleeve, if needed.
Set the lower piston in a vice but, before tightening, add wood packing to prevent damage the jaws. Lightly lubricate with silicone spray.
You’ll need plenty of force. The top plate may need to be supported while you pull the rubber sleeve down onto the piston.
Carefully check the locating pegs are in line. If not, the spring may twist as it inflates, which should be avoided at all costs.
Refit the completed air spring assembly into the vehicle, checking it is fully seated. Now replace the four retaining clips, using new items.
Refit the air feed pipe to its connector in the top plate – simply push it into the collet, then gently pull it outward again to tighten the fixing.
RE-COMMISSIONING THE SYSTEM: Start the vehicle – the spring will slowly inflate. It will only reach the required volume with the wheel off. Lowering the axle will help.
Refit the wheel, then remove the axle stand and the jack. The bag should inflate fully, and look like this (wheel is off here only for photo).
Run the EAS system through the different height settings to check the system operation. Then road test the vehicle with initial caution.
Looking back, the old air bags had clearly distorted. The new ones are more supple and have reinstated the legendary Range Rover ride.