LS430 front suspension keeps dropping

[LSE]

I just recently bought a 2001 LS430 and It’s got an issue with the front suspension dropping usually over the course of 3-4 hours. The front end of the car is nearly on the floor when I go to it after leaving it overnight. 

When I got the car I had an issue where the rear of the car would be stuck in the high setting so I done a Battery reset which sorted the rear suspension but the fromt still keeps dropping. Although when I press the high button the car will raise and get stuck in the high position again so will have to do another Battery reset to fix

Also something else I’ve noticed that when pumping the suspension up when it’s low, it takes about 5-10 minutes and the pump will kick on and off even though the front suspension is low. Is this normal?

also any ideas on the suspension dropping? I have checked the shock absorbers and can’t see any moisture anywhere or any obvious leaks  is there anything else I could check? 

Appreciate any help because I haven’t had the car long and hope to get it sorted. I like the car but the suspension is sending me mad 

 

[The-Acre]

If it's dropping it sounds very much like you have a strut leaking air.  You could be lucky and find it's a height sensor but I would think it's the former. You should be able to hear the air escaping.  It could of course be a damaged air hose.  It really needs to be checked by a specialist.

[royoftherovers]

47 minutes ago, LSE said:

I just recently bought a 2001 LS430 and It’s got an issue with the front suspension dropping usually over the course of 3-4 hours. The front end of the car is nearly on the floor when I go to it after leaving it overnight. 

When I got the car I had an issue where the rear of the car would be stuck in the high setting so I done a battery reset which sorted the rear suspension but the fromt still keeps dropping. Although when I press the high button the car will raise and get stuck in the high position again so will have to do another battery reset to fix

Also something else I’ve noticed that when pumping the suspension up when it’s low, it takes about 5-10 minutes and the pump will kick on and off even though the front suspension is low. Is this normal?

also any ideas on the suspension dropping? I have checked the shock absorbers and can’t see any moisture anywhere or any obvious leaks  is there anything else I could check? 

Appreciate any help because I haven’t had the car long and hope to get it sorted. I like the car but the suspension is sending me mad 

 

Eddy,

Did you buy the car privately or from a Dealer ?

[LSE]

21 minutes ago, royoftherovers said:

Eddy,

Did you buy the car privately or from a Dealer ?

I bought the car privately. When I picked up the car i did notice a slight difference in the height of the front and back but I thought I could adjust the height sensors to fix this. But then the morning after I bought it I went out to it, and the front of the car was completely sunk while the back was sky high. I’m just glad I got the car for a good price so I can hopefully sort this issue. Im a bit stuck as to what to do to fix the sinking front suspension 

[royoftherovers]

8 hours ago, LSE said:

I bought the car privately. When I picked up the car i did notice a slight difference in the height of the front and back but I thought I could adjust the height sensors to fix this. But then the morning after I bought it I went out to it, and the front of the car was completely sunk while the back was sky high. I’m just glad I got the car for a good price so I can hopefully sort this issue. Im a bit stuck as to what to do to fix the sinking front suspension 

Thanks Eddy. It seems that you need the services of a good Indie then.Where abouts in Cheshire are you ?

[GrahamG]

When the ride height sensors seize up the connecting arm can break. Worth looking to see there are no broken arms.

On the US owners club site search for a diagram of the pneumatic plumbing system and some soapy water might show a leak. There is a 4 way manifold for instance that is easy to check.

The pre facelift models, ie your car,. were offered without air suspension. For the cost of renewing one corner with air suspension you could replace all four corners with conventional Lexus steel. That is a common remedy in the US.

[Newbie1]

Converting to springs probably would be your most reliable bet, and reports from the US are that conventional  Lexus springs don't feel too much different from air. In Japan they offered the model without springs for the whole production run so OEM springs shouldn't be hard to source.

[GrahamG]

Phil, are you saying the steel spring suspension was offered in Japan for the facelift car ie 2004 to 2006?

If that is the case then I will certainly convert if my air system fails.

I changed from a '95 Ls400 with steel to a '04 Ls430 with air and  experienced no improvement whatsoever.

[Newbie1]

That is correct. The UCF30 Celsior, versus the UCF31 C spec Euro variation offered in the UK.

 

ETA: I am keeping my eye out for the UCF30 in Japan as finding a decent earlier UCF20 facelift steel spring Celsior is very hard.

[Jake430]

When my rear air bags burst I changed front and rear air suspension to coilovers, three of them leaked within a short time. Refitted the front air shocks and got Lexus 

shocks and springs for the rear. Car handles great.

[GrahamG]

Eddy, I should say second hand air struts are available on eBay and are easy to fit.

One advantage with air is that if just one has failed it is not necessary to replace any others at the same time.

Beware that all four struts are not necessarily the same. 

[GrahamG]

Jim, what year is your Ls430 please?

Coilovers have a mixed reception in the US and seem less successful if the original Lexus ride is required. 

[GrahamG]

Jim, I see it is a 2004, could you confirm it is the facelift model?

[Jake430]

1 hour ago, GrahamG said:

Jim, I see it is a 2004, could you confirm it is the facelift model?

Yes it is the face lift model.

[GrahamG]

Jim, can you give any details of the change to the rear Lexus steel?

Any part numbers? Was it just a spring and shock absorber or was a top mount or bumper required?

Who did the work, presumably not a Lexus main agent?

Any problem with the dash warning light?

[Jake430]

 

if you can go back through my posts to about July 2015 all parts required are listed.

I did the work myself.

The light for the suspension stays on.

[LSE]

8 hours ago, Newbie1 said:

Converting to springs probably would be your most reliable bet, and reports from the US are that conventional  Lexus springs don't feel too much different from air. In Japan they offered the model without springs for the whole production run so OEM springs shouldn't be hard to source.

Does anybody have any links or know anywhere where I could find LS430 coil spring suspension?

ive been looking round but the closest I could find was coil overs but I would prefer normal shocks and springs. 

Also an update with my car is that I replaced the rear height sensors which has improved the ride quality and the car sits a lot Nicer now. But the front end still sinks. Seems like the NSF sinks more than the OSF. Will jack it up on the weekend and see if I can find any air leaks. Hopefully it’s something simple not a shock absorber but if it is I’ve looked and seen you can get second hand ones on eBay at a reasonable price. 

[Jake430]

1 hour ago, LSE said:

Does anybody have any links or know anywhere where I could find LS430 coil spring suspension?

ive been looking round but the closest I could find was coil overs but I would prefer normal shocks and springs. 

Also an update with my car is that I replaced the rear height sensors which has improved the ride quality and the car sits a lot Nicer now. But the front end still sinks. Seems like the NSF sinks more than the OSF. Will jack it up on the weekend and see if I can find any air leaks. Hopefully it’s something simple not a shock absorber but if it is I’ve looked and seen you can get second hand ones on eBay at a reasonable price. 

Get them from Lexus. I fitted coilovers first, they did not last long. Maybe the Lexus was to heavy.

[GrahamG]

Eddy, have a read of Jake430's posts in July 2015. There he lists the Lexus parts for the rear suspension in steel.

These cost him 1,100 Euro so to do all four corners will be much more expensive than I suggested above [@10.20am] which is the oft quoted relative cost in the USA.

Lexus Birmingham would be worth a try to give you an idea of costs in the UK.

Amayama in Japan are often favoured on this forum but there are extra import costs.

[Newbie1]

Coilovers are not right for a normal driver of this car. The spring rates of most of them are about double OEM, and not much point in paying for features you are not going to need, although it might be fun to play with damping rates. They won't last as long as normal springs, either. Many come with steel top mounts, not rubber, increasing the chance of noise. Toyota got it right first time.

[messi]

There was a guy recently selling an ls430 on Facebook. He replaced the air suspension with the Lexus ls400 suspension and said it drove great 

[LSE]

Just an update on the LS430 I was spraying soapy water on parts of the suspension and there is a pipe going into the NSF shock absorber which runs by the dipstick of the engine. It had a piece of rubber hose on it which I don’t know if it’s there originally from the factory. I sprayed it with soapy water and then it started to bubble out quite a bit from that pipe. Went to Halfords and got a new piece of rubber hose and some clamps and replaced the rubber pipe that was there but I pushed the rubber hose onto the air line/pipe about 2 inches on both joints. Ran the car up to pump the suspension back up and rechecked the pipe for leaks and now there are no bubbles so hopefully that was the issue so won’t need to buy any shock absorbers. Although I think standard springs and shocks would be a better idea than the air suspension. If it does fail again I might consider swapping over to springs if I find some

 

[dendonc]

32 minutes ago, LSE said:

Although I think standard springs and shocks would be a better idea than the air suspension.

I know zilch about the mechanics etc, but, the link below is to Lexus' official online store, they might have what/somethings you want,see link:

http://stores.ebay.co.uk/LexusOfficialStore

[The-Acre]

Well that'll be a great result if it's just a repairable leak.

[Newbie1]

On 12/01/2018 at 4:42 PM, messi said:

There was a guy recently selling an ls430 on Facebook. He replaced the air suspension with the Lexus ls400 suspension and said it drove great 

Interesting that the LS400 springs and shocks will fit the 430. Very useful info.