100 Air Suspension FAILURE - And Fix

[ZAD329]

Being a not-so-proud former-owner of a 2001 Land Rover Range Rover, I had my misgivings about air suspension. (Two weeks after I bought the Rover, the air suspension failed. Rather than repair, I took the system out and replaced with coils.)

When looking for a 100-Series, I was naturally skeptical of purchasing another behemoth truck reliant upon a similar system. I did my homework, and could not really find any major problems, past or present, with the Toyota system. Hence, in December 2012, I purchased a beautiful 2006 100-Series.

Fast forward to last week...

Driving out of my office parking lot, I knew something was wrong. It felt as if the front, passenger tire had gone flat. I immediately stopped, only to feel the whole truck lurch towards that front wheel-well. Another crazy thing happened - the center-diff engaged. Completely confounded (and not wanting to do any further damage) I put the truck in park and called AAA.

As it turns out, the air suspension system had a small leak which, over time, drained the entire system of its fluid. My mechanic found the leak, patched it, re-filled the fluid and viola! The truck again rides like a dream. Insofar as the center-diff suddenly becoming engaged, I'm open to thoughts. The guy at the service desk tried to tell me "the button had been pushed." I smiled and explained that I am not a soccer-mom and understand what center-diff is, actually using it on occasion. I'm guessing they have no idea as to why it engaged, either.

Before we realized it was just a small leak, I was mentally preparing myself for a $1000-$2000 repair bill; call it "Range Rover Syndrome". Thanks to a great mechanic with a good-eye, the tab came to $46. I've said it before and I'll say it again - these are the best vehicles in the world.

 

[Junglejack]

Hello,
On the whole the AHC has proven to be quite durable. Your experience somewhat attests to that. Worst case, you can relatively easily retrofit to a conventional suspension.

I do wonder if AHC's reputation would be different had it been offered on US LC's from the start. With AHC being offered on ROW LC's from the launch on the top trim levels, I think the perception is different. Whereas here it is thought by some to be Lexified.

Interesting about the CDL. Could it be part of a "limp home mode"? Does your mechanic specialize in LC/LX's?
Best,
Jack

 

[Lx470iH8Mud]

Not uncommon for people to accidentally engage the diff lock with a knee, perhaps this happened when you were moving about the drivers seat trying to decide what tire was flat when you AHC was giving trouble. Outside of that, I don't see how the diff lock would have been engaged.

 

[Skidoo]

Did you turn on the emergency flashers? Can easily hit CDL at same time if you are rushing.

 

[arbetrader]

If the whole fix cost only $46 I'd want to be doubly sure that the fluid they used was in fact the property Toyota AHC fluid and not just brake fluid etc - it's usually an order-in item only. Any other fluid in the AHC system will damage it long-term. You usually need 2 cans for a FULL system flush - around my parts it runs around $45/can. Just an FYI because for what you paid, that seems awfully cheap if they used the correct stuff.

 

[rustydrummer]

If the whole fix cost only $46 I'd want to be doubly sure that the fluid they used was in fact the property Toyota AHC fluid and not just brake fluid etc - it's usually an order-in item only. Any other fluid in the AHC system will damage it long-term. You usually need 2 cans for a FULL system flush - around my parts it runs around $45/can. Just an FYI because for what you paid, that seems awfully cheap if they used the correct stuff.

I'll second this...I have priced the Toyota Ahc fluid for my own purposes. $42 a can at my local Toyo dealer... I have seen it for $31 a can online, not including shipping. 2 gallons is what I've heard it takes to flush and refill the system.

 

[hankinid]

I'll second this...I have priced the Toyota Ahc fluid for my own purposes. $42 a can at my local Toyo dealer... I have seen it for $31 a can online, not including shipping. 2 gallons is what I've heard it takes to flush and refill the system.

2.5L per can, just a tad over half a gallon.

I've done the flush and refill twice. A single can of AHC fluid was just enough to get clean fluid from the accumulator and the wheel spheres each time.

No idea why 2 gallons would be needed.

I usually get 2 cans at the dealer, use one and have one as a spare.

Steve

 

[rustydrummer]

2.1L per can, just a tad over half a gallon.

I've done the flush and refill twice. A single can of AHC fluid was just enough to get clean fluid from the accumulator and the wheel spheres each time.

No idea why 2 gallons would be needed.

I usually get 2 cans at the dealer, use one and have one as a spare.

Steve

Ah, my bad. I had been told that it takes two cans, haven't done it myself. I just assumed each can was a gallon. You know what happens when you assume...

 

[APKhaos]

Not uncommon for people to accidentally engage the diff lock with a knee, perhaps this happened when you were moving about the drivers seat trying to decide what tire was flat when you AHC was giving trouble. Outside of that, I don't see how the diff lock would have been engaged.

^ THIS. Its easy to knee the diff lock button without realizing that its happened. Its fairly obvious - the steering weight is a dead give-away. Given there's no coupling between the AHC and Diff Lock systems, I'd bet you kneed the button at some point.