2004 Grande Air Suspension leak

[dazza65 Lurker Find all posts View Profile Close dazza65]

Hello All,
I noticed about 6 months ago my rear suspension would lower to the rear bump stops overnight.
I assumed this was caused by a slow air leak but wasn’t an urgent problem as the suspension height is continually adjusted when the car is in use. I mentioned to my mechanic at service but said he couldn’t find anything and would need to keep it overnight to investigate.
The problem seems to have got worse now which can be good as it will be easier to find the leak/problem but doesn’t seem to be consistent
The car can sometimes fully lower in less than hour and at other times stay up the whole day when I am at work. It doesn’t seem to be related to the angle it is parked on as far I can see.
I have sprayed all the connections that I can get to with soapy water and can’t see any leaks.
My next plan is to crimp of airlines with vice grips to isolate areas of the system to see if I can identify a different lower rates to pinpoint where the leak is.
Has anybody had similar issues and if so what did the cause of the problem end up being?
Daz

[kav Avid PP Poster! Find all posts View Profile Close kav]

i have the same problems although i may only see it as a problem when the compressor fails . im going to wait until total failure so as to avoid spending an inordinate amount of cash letting idiots with no idea chase a problem that they have much less an idea about than i do . think of it this way . when it drops down it looks fully sick when its parked , and its easier to get in to . and if you drive out of the driveway quickly and up the road , it looks like a really fully sic wagon driving on the bump stops . how much street cred is that dude . a prado on the bump stops . siiiiiiiiccckkk maaaaaan . if you cruise around auburn you'll fit right in . just don't forget your maaaaaaaasive subwoofer bro , ill have to get one soon .

[dazza09 Lurker Find all posts View Profile Close dazza09]

dazza65 did you ever find out what the problem was as I have the same drama and yes trying to find what is exactly leaking is a mission

[Guest Close Guest]

dazza65 did you ever find out what the problem was as I have the same drama and yes trying to find what is exactly leaking is a mission

What year is your Grande? Check if there are any tears in the airbags as the rubber deteriorates with age and heat, especially the driver's side which is the first one to go.

[dazza09 Lurker Find all posts View Profile Close dazza09]

amts my grande is 2005 looked for leaks have still not found any, it stays up when set in high but when on normal heights drops within hours?

[kav Avid PP Poster! Find all posts View Profile Close kav]

That means the airbags are stuffed , ill post pics of what happens to them later

[kav Avid PP Poster! Find all posts View Profile Close kav]

the first and third pics are what you probably wont see if you get under the car and look at it . the second one is how it looks when its set on high albeit without any air pressure . the airbags develop cracks in the rubber and leak . if you put them up on high the cracks close up and will hold air for longer . when you start the car after the bags have deflated it sometimes takes a while for it to register and pump them up .hence the bumpstop ride

[gogo Lurker Find all posts View Profile Close gogo]

If you can ignore the height control dash light flashing at you, then try this. Set the height control to high then pull the height control fuse out when they are pumped up. Stops them deflating once you start driving. I had a same issue and this would last me about a week before I had to put the fuse back in and pump them up again. By no means a fix, but will get you out of trouble and save your rear shocks and spare you the donkey ride you get when its on the bumpstops.

[loucap Lurker Find all posts View Profile Close loucap]

I have a 2005 model currently with ~180,000 on the clock and have had similar issue since late 2015 ~165,000. I asked the dealer to check at ~170,000 but he couldn't find any problems and said to leave it. Not sure if it's a coincidence but the rear diff was fixed/recoed at ~164,000 clicks. Asked the dealer if the diff work caused the problem but even though they couldn't find the problem he indicated that it wasn't related. Too much of a coincidence for mine.

Usually deflates but occasionally stays up overnight. As mentioned in this thread it does tend to stay up when set to high which gives weight to the cracks being closed and not letting air out. I've been living with it nearly 2 years. Pump keep working but wondering if the pump is integrated or it's a bigger expense when the pump goes.

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The compressor is a bigger expense. Swap out the airbags as it is aged before the compressor wears out.

[loucap Lurker Find all posts View Profile Close loucap]

Might be a waste of time but I thought I would give a bit of an update and share my experience(s). It's been a great car, 17 years, 217k kms and still loving it...... APOLOGIES FOR THE LONG POST

It's been a while since my post above and there are quite a few more posts on various old PP threads about this issue and appears to be some confusion about the Grande Airbag issue. Also it's surprising that Toyota service didn't really have a handle on the problem and were reluctant to start with bags and then have to replace compressor or visa versa and very expensive to diagnose and not solve the problem first time.

To recap as per Dazza09 in the beginning I found that the rear would stay up when on High. In my case it stayed up indefinitely if parked on High so the drill was to lift it to High when parking. There seems to be some truth in the theory on the cracks being closed up when in High stopping the deflation, however, if anything you would think there was more pressure and higher likelihood of deflation. At the very least it would be logical that it would deflate over time but it didn't so not so sure about the cracks theory.

I took my car to Toyota service centre (TSC) on 5 occasions over 3.5 years prior to Nov 2020 to see if they could sort it out. On the first 4 times the rear was up and in the N position. It's weird but seems the car sensed that I was taking it to Toyota and it stayed up. Toyota could not see any faults in the system and reluctant to start replacing anything due to cost and they wouldn't guarantee it would be fixed. I did have the rubber bump stops replaced at the crazy cost of $360 ($180 plus labour - should have done it myself) as the old ones had seen better days and I didn't want to damage anything if car was driven on bumpstops.

At one point the Toyota mechanic adjusted the sensors and raised the system higher (closed the cracks? maybe). This worked on an off for about 2 years, that is it stayed up for the most part for 18 mths but then it dropped down on a regular basis. Then the height control system itself started to falter when the compressor would time out and fail to reset, particularly if there was weight in the cargo area. Initially I could reset the system by turning off the engine and the height control button would work but in the end the system would not reset at all. What is weird is that on 1 or 2 occasion the system would reset itself while driving, weird.

In the end in Nov 2020 after coming out of lockdown I reached the end of my tether after driving for 10 kms on the bump stops. The compressor would time out and not reset as it previously did after cycling the ignition. A week later system decided to reset and I got bags back up (btw you could disconnect wiring to the compressor and would do the same thing). I took it to TSC the next time it dropped and stayed down. TSC disconnected the battery to reset the compressor system. After having the car for over 2 weeks and $160 they told me that they 'suspected' the compressor was leaking internally and and quoted $1650 to start there. They said the air bags, other than having stress marks had no visible damage. However, their recommendation was to install a fixed suspension system.

I was reluctant to put a fixed suspension as I liked to keep it original with the height control. I did a bit of goggling and found a compressor that fits 120 Prado and Lexus GX470 from an after market parts distributor call Maxpeedingrods (US outfit with warehouse in Sydney) for $200 (back then) shipped in 3 days and had a friend's mechanic fit it. They felt that the bags were ok, however after fitting the new compressor it blew the old bags. For $100 (yes $100 back then) I bought a pair of new airbags from the same place. All done for $750 and figured if system only lasted a couple of years it would be ok at that price. All was good and while not having done any real 4x4 driving for 15 years I went to Mt Buller / Sterling on some semi serious tracks a few times without any issues.

All was going well until the day I went to Walhalla and went down the Deep Creek No1 Track after heavy rains (double bad combination), got to within 100 metres of the creek at the bottom before having to turn back up as the bottom was near on impassable. It's a very very steep and difficult track, particularly when wet. Managed to get a third of the way back up before getting stuck in a rut and pushing it too hard. Ended up blowing the right airbag and the weight of the car crashing down onto the axle caused the Diff to blow. Maybe I'm wrong but I put it down to inexperience rather than bad air bags. Should not have gone on such a difficult track with a stock std Grande. I also had the height control on high for the extra clearance, thinking it was the right thing to do. Was told by the recovery guy that that was a no no as it put extra pressure on the bags. It might have been ok if I had taken it a little easier and smoothed out the ruts. Anyway the shark motor mechanic suggested that I put a fixed suspension as the Toyota bags were hard to get and expensive. I went online and ordered a pair of bags from Maxpeedingrods for $150 that shipped earlier than the new Diff Centre from Melbourne. Lets say the Bags were a small fraction of the cost of everything else. All good now but very weary about taking on any serious tracks.

[Piggy Water pistol pilot. Find all posts View Profile Close Piggy]

Sounds like you got aftermarket bags for that price, theres plenty of issues and previous stories around with aftermarket falling out on 4wd'ing when you have large droop. Airbag man and ebay ones have been known to do it. Especially if the rear sensor has been tricked to "lift" the rear higher when its on its "N" setting. 40mm is the very maximum you can do on standard bags, and even then you should secure the base pins to stop them being able to come out on large articulation.
Genuine bags aren't that dear from partsouq.