Bouncy suspension

[ryangus Lurker Find all posts View Profile Close ryangus]

Hi - first time on Prado point, as I don't actually own a Prado.

A mate of mine who's not computer savvy has an issue with his 2003 Grande. He rang me to ask about my custom air bag suspension in my vehicle (not a Prado), as he believed he had a problem (he thought a leak) with his rear bags.

The symptom is bounciness in the rear. I was puzzled by this - I would have naturally thought that would mean failed shocks, not bags. Failed bags would have it sitting on the bump-stops and a constantly working compressor, right? He claims it doesn't appear to be sagging in the rear end.

I'm not sure if they physically inspected it, but Pedders I think tried to talk him into replacing the air-bags with springs (a feasible option in a Land Rover Discovery and Range Rover).

He never takes this off-road, and is looking for the cheapest option he can find (money's tight). I would prefer to steer him towards the most inexpensive option, rather than cheapest (IMHO there's a difference!).

Anyway, anyone able to advise what they think the problem is, and the most inexpensive remedy? If it's bags and/or compressor, are they easy to replace? Surely shocks are a 10 minute job?

Thanks for your advice.

[Guest Close Guest]

Sounds like Pedders are pulling their normal dodgy crap..
It will be shocks if it is bouncing. As there is nothing to control the movement.
If the bags are failed it will have a compressor running most of the time. And will be sitting low.


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[ryangus Lurker Find all posts View Profile Close ryangus]

Sounds like Pedders are pulling their normal dodgy crap..
It will be shocks if it is bouncing. As there is nothing to control the movement.
If the bags are failed it will have a compressor running most of the time. And will be sitting low.


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That's what I thought. Any suggestions on what shocks to go for and where to get them (entry level will do)?

[Guest Close Guest]

Need more information.

What is the front and rear suspension heights?

Can he cycle through the 3 height settings?

If he leaves the Prado alone for long periods of time, does the rear lose some height?

Can you define bouncy like driving on bumpstops or like there is no damping?

What position is the shock setting? Comfort - sport?

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

Seeing I have just replaced both the bags and shocks on my car , and his is a 2003 , I will put money on it being the airbags , not the shocks . The airbags only last 8 -10 years . The shocks will last a lot longer . More info is needed . I just helped out a client of my mechanic who had the same problem . Toyota changed the shocks , it didn't solve the problem . If you do a search on this site you will find it covered in depth . If you take it to a mechanic it will cost 8-$900 to replace . If you order the parts through partsouq.com in the UAE it will cost half of that.

[ryangus Lurker Find all posts View Profile Close ryangus]

Thanks Kav,
I'm yet to see the vehicle, but he tells me there's oil leaking out of the shocks. I think we should start with them, as they're probably needed and not real expensive.

If it doesn't fix the problem, I'll try the bags. Do you reckon the compressor will also need replacing? Is it a difficult job for someone good at tinkering (but not a mechanic!)?

Finally, do you have the part numbers for the bags and compressor?

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

Oil leaking from the shocks is not a good sign . The rear shocks are easy to replace. The compressor should be fine . The airbags have a clip that holds the air lines in that can prove difficult to deal with .

[ryangus Lurker Find all posts View Profile Close ryangus]

A little more info was provided last night. Apparently 'over Christmas' the compressor was inflating and deflating the springs repetitively whilst stationary. I'm going over to have a look tonight.

I still can't get my head around what part of the air suspension could be faulty. Surely leaking bags would result in the vehicle sitting on the bump stops and/or the compressor working overtime - correct?

Is there any way to test if the bags are actually leaking? Could the bags be fine, but some of the electrickery be faulty?

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

Have a look through the 120 suspension section, make sure your settings let you check archives because I think the default cuts off earlier years. I don't have a Grande (hooray) but I have read of this before in here. Also some people have had leaky bags (!) and the suspension still works. Try sending amts or craigm a pm they may have more accurate info.

[Guest Close Guest]

A little more info was provided last night. Apparently 'over Christmas' the compressor was inflating and deflating the springs repetitively whilst stationary. I'm going over to have a look tonight.

I still can't get my head around what part of the air suspension could be faulty. Surely leaking bags would result in the vehicle sitting on the bump stops and/or the compressor working overtime - correct?

Is there any way to test if the bags are actually leaking? Could the bags be fine, but some of the electrickery be faulty?

The bags will have a tear in the fold. So when inflated, the tear becomes slightly exposed. It then leaks slowly and the fold seals up the tear when the bag is a bit deflated. So the compressor detects that the rear is now a bit low and starts to pump up again. It will then keep on repeating the cycle.

Is the Grande lifted?

[ryangus Lurker Find all posts View Profile Close ryangus]

Have a look through the 120 suspension section, make sure your settings let you check archives because I think the default cuts off earlier years. I don't have a Grande (hooray) but I have read of this before in here. Also some people have had leaky bags (!) and the suspension still works. Try sending amts or craigm a pm they may have more accurate info.

Thanks, will do.

[ryangus Lurker Find all posts View Profile Close ryangus]

The bags will have a tear in the fold. So when inflated, the tear becomes slightly exposed. It then leaks slowly and the fold seals up the tear when the bag is a bit deflated. So the compressor detects that the rear is now a bit low and starts to pump up again. It will then keep on repeating the cycle.

Is the Grande lifted?

It's not lifted.

That sounds logical, except my mate made no mention of the compressor repetitively kicking in. Would this be audible/noticeable (particularly to a numpty!)?

[Guest Close Guest]

The compressor is near the rear passenger side tyre. Cycle it through the LO, N, HI settings and you will hear the compressor working.
To check the tear, you will need to jack up at the chassis and allow the axle to fall at full droop.
Refer images here on the location of the tear
http://www.pradopoint.com/showthread...l=1#post383673

[Guest Close Guest]

PM Wholesale suspension, he is a wiz on gear for the Grande's.
http://www.pradopoint.com/member.php...salesuspension

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

The compressor cutting in and out will be hard for a numpty' to notice while driving . From what you describe I would say he needs to replace both bags and shocks . I would replace the bags first . I replaced the bags first , this fixed the problem . Then I replaced the shocks as they had done 205000 ks , this made very little difference to the ride . As I said earlier , I met another Grande owner who had his shocks replaced by toyota and was very pissed off because it made no difference but he was out a bucket load of cash . You can jack the car up and look all you want but the bags have a protective shroud around them and you probably won't see the tears in the bags until you take them out . I have posted pictures of what happens in the 120 grande suspension thread .