PaulP38A.com

The EAS (Electronic Air Suspension) Valve Block is one of those many, many things that Land Rover will charge you a small fortune to replace. A major cause of problems associated with the valve block is the o-rings wearing out. Fortunately these can be replaced fairly easily and cheaply.

This procedure has been documented before, such as this page at RangeRovers.Net. My attempt at documenting the rebuild procedure is a bit more verbose than others I’ve found… mostly for the benefit of keen amatuers such as myself. I took these pictures as a record of what I was doing so I could remember how to put it back together again.

Another subtle difference between this page and others is that my EAS system has an air-locker regulator, onboard air kit, and EAS Emergency Bypass Kit installed. If you are thinking of installing these add-on components to your Rangie, parts of this guide may be useful as you can see where these units are patched in to the EAS system.

Note: this page has been updated as of May 2010 with additional detail, and a change in method from removing the entire EAS housing to only removing the valve block.

Intention of this project

I believed I was getting a slow leak in the EAS from inside the valve block and decided to replace the rubber o-rings. Most of this procedure applies if I had wanted to replace the diaphragm too.

Preparation

A complete set of o-rings for the valve block from Rover Renovations in the USA, or Hard Range in Australia.

A diagnostics tool such as EASunlock or FaultMate to depressurise the EAS and then to test it afterwards. Dennis Altman of Rover Renovations has documented a method of depressurising the EAS using a set of “pigtail” wires at this page.

Assortment of spanners, screwdrivers, pliers, cleaning fluids and rags.

A few hours to spare, plenty of coffee/tea and suitable background music… I chose “Movie Hits of the 80′s” and “70′s Greatest Hits” for this job.

Cleaning the removed bits and pieces

I just used a clean rag sprayed with a bit of WD-40 to wipe the block parts down until they looked shiny again. I’ve read on other guides that cleaning the block with soapy water and letting it dry slowly in a warm (not hot) oven also works. I didn’t have the patience to wait that long and I’m pretty happy with the results I got.

For the airways, I used a can of computer keyboard compressed air to blow any dust and WD-40 residue out.

For the plastic case, you can’t go past Windex (or similar) glass cleaner in my view. I didn’t worry about trying to make the plastic case too clean as it is just going to get filthy again real soon.

Removing the EAS unit

Depressurise the EAS system using your tool of choice. I used EASunlock from Storey Wilson.

If you have an EAS Emergency Bypass Kit (EBK) fitted, you can purge the last bit of air in the system through the inflator valves.

IMPORTANT: after depressurising the EAS, leave the ignition switched off until you have finished this procedure and reconnected the electrics. Otherwise you will generate an “EAS Hard Fault” which you will need to clear with a diagnostics tool or by a dealer.

The next photo shows the air line connections to the EAS box. If you don’t have a EBK fitted, ignore the tee-pieces.

A top view of the EAS housing with the cover removed. Never mind that I’ve got an oversized air compressor in mine, the process is the same for a “normal” unit.

Location of the two screws that secure the Cruise Control unit. You need to remove these to get easy access to the bolt at the rear of the EAS that holds the valve block and driver unit in place.

Remove the three nuts holding the compressor in place and then lift it a little to get access to the air line below.

Use a 12mm spanner to undo the brass nut holding the air line in place. Note the Tee-piece on mine is used for the air-locker.

With the compressor removed.

Use a flat blade screwdriver to unclip the wiring harness from the casing.

Slide the retaining clip to the side to release the wiring loom.

Remove the second retaining clip and unplug the wiring connectors.

Unscrew the exhaust valve filter/silencer and put aside.

Use a screwdriver or needle-nose pliers to depress the collets on the airlines going in to the housing and pull out the air lines.

If you are inclinded to do so, you could label each of the air lines to ensure you know which one goes where. However, I’ve found that mine line up pretty well with the case and not much guesswork is involved.

It is a good idea to cap off the exposed air lines to prevent dust and moisture entering.

The picture below with the air lines pulled aside gives better visibility of the two bolts that hold the valve block in place.

Use an 8mm socket or spanner to remove the two bolts on the air line side of the housing, and another bolt at the rear near the cruise control unit.

Remove the two cable clips on the side of the case to make it easier to remove the valve block. A flat screwdriver blade at the back of the clips will help them pop right off.

With the clips removed, three bolts removed and wiring connectors disconnected, the valve block and driver unit should slide straight out.

The removed unit on the bench ready for further disassembly.

The brass fitting is the pressure relief valve. The green one is the pressure switch.

I recommend numbering the solenoids so you remember which one goes where.

Remove the wiring loom/connector from the bottom of the unit.

Use a 14mm spanner to unscrew the pressure switch.

Remove the driver unit by undoing the four allen key bolts.

Noting the orientation of the solenoid covers, remove the five on top and two underneath the block.

A view from above. Note the smaller solenoid at the right.

Note the orientation of the solenoid bases for re-installation.

The solenoid bases are held in by two flat head screws each. Remove each of the solenoids and place them with their corresponding covers for safe-keeping.

As you remove each solenoid base, note the two o-rings underneath.

Turn the block over to remove the final two solenoids, and the four allen-head bolts that hold the diaphragm block in place.

The inlet solenoid and diaphragm block removed. Don’t lose that spring.

Removing the old o-ring from the diaphragm.

Gently remove the metal cap from the diaphragm.

At the other end of the valve block, remove the four allen head bolts.

Carefully remove the block to reveal the non-return valves. Note the orientation of the valves for reassembly.

Remove the valves and o-rings.

Turning the block on its side, prise out each of the collets with a small flat screwdriver blade.

Finally, fish out the two o-rings from each of the holes that the collets were in (yes, for the keen-eyed… the pic below was taken after the inlet block was replaced).

Replacing the o-rings

The o-ring kit contains more than enough o-rings to replace all the o-rings in your valve block, plus a few extras in case you make a mistake.

Generally, it is a good idea to coat the o-rings with the supplied o-ring lube or some Vasolene to assist in sealing.

The order of replacement is up to you. This is how I did mine.

Starting at the NRV end of the block, replace the o-rings on the NRV’s. Use a small flat head screwdriver to remove the old o-ring and slide the new ones in place.

NRV’s reinstalled with new o-rings. I’ve been told that Vasoline/o-ring lube and NRV’s don’t mix, due to possible binding, so I spared it here.

Replace the NRV block and tighten the bolts.

Go to the other end of the block and replace the o-ring around the diaphragm recess. New o-ring inserted below with a touch of lube to aide in sealing.

Although I had a spare diaphragm in case I needed it, the existing one looked fine (not ripped or worn) so I re-installed it.

Reattach the block and secure with the four allen-head bolts.

Next, insert the o-rings in to the air line holes. Each hole will take two o-rings to give a good seal.

It is pretty obvious which holes takes the 4mm, 6mm and 8mm o-rings.

A top tip from Shadow Keeper at RangeRovers.net:

“When I re-built mine I kept finding that the air-line keeper o-rings kept folding when I tried to seat them in the valve block. I ended up using the blunt end of a drill bit (can’t remember if it was an 8mm or 6mm) and pushed them in that way, it really did the job.”

Good advice, and it worked well for me too. An 8 or 9mm drill bit for the 6mm o-rings did a good job of seating the o-rings in the holes.

With the o-rings in the holes, push the collets back in and check the pathway is clear by pushing a smaller drill bit through the hole, i.e. a 5mm drill bit though a 6mm hole, etc.

Replace the top and bottom o-rings for each of the solenoid valves. Again, a little lube helps to seal it.

Don’t forget to replace the inner o-ring as well.

You can also replace the o-ring on the shaft of the solenoid valve if you want to be thorough.

Replace the solenoids in the same orientation and position as you removed them. Top view.

… and bottom.

Replace the driver unit.

Note how the footing locates under the bracket.

Replace the pressure switch. I applied a dab of Loctite thread sealant to keep it sealed.

Reattach the air line olive with a 12mm spanner.

Place the block back in the housing and secure with the three bolts. Two at the air lines side and one at the rear.

Screw the exhaust filter/silencer back in place. Re-insert the air lines by pushing firmly in place and then pulling back a little. There should be no movement at all.

Push the cable clips back in and secure the cables. Re-connect the two wiring multi-plugs.

Replace the compressor and tighten up the air line olive connector at the compressor side.

Tighten the nuts holding the compressor vibration mounts in place.

Mount the cruise control bracket and secure with the two screws removed at the beginning of this exercise.

That’s all folks.

All that’s left to do now is pump up the system, leak test and replace the cover of the EAS housing.

In case you were wondering, the orange curly hose and pressure guage at the left of the photo above is an onboard air system that I use to inflate my tyres and/or clean the air filter. The pressure regulator keeps outgoing air pressure at less than 50psi and the 5m hose reaches all tyres.

Leak Testing

With the compressor running, and adjusting the vehicle to different heights, spray all connections with a mixture of soapy water and look for leaks indicated by bubbles on the connections.

If you find a leak, push and pull the air line connector and test again. If the leak persists, cut a couple of mm off the line to give a nice square connection.

To avoid flattening the battery, leave the engine running while doing these tests.

Rubbing and Vibration

If you experience excessive cabin noise due to the air compressor operating, you might find that the EAS housing is rubbing on the body. You can see at the centre right of the picture below where the EAS housing was rubbing on the body of my P38.

The housing can be lifted approx 5mm by inserting a metal machine washer and three fibre washers. To hold these in place, I put a dab of glue between each of the washers and then used some cloth tape to align them with the holes in the body.

The picture below shows the extra 5mm of lift afforded by the washers.

Follow-up

After a few days of running the renewed system, I’ve had no problems with the EAS.

I’d recommend keeping an eye on it for at least a week as the new components bed-in and I’ll be re-checking the nuts and bolts to make sure they haven’t loosened up in the coming weeks.