LS400 Air Suspension

1990 LS400 250,000 mi - electronic air suspension

I realize the electronic air suspension is an issue on early LSs. I
have replaced one air unit (rear) a few months ago. The car performed
well for a few months but now the suspension is acting up.

The car will hold the suspension correctly for several days/weeks and
ride great. The suspension will (ususally) be at the same height when
left parked overnight.

But the car may drop in the rear to the ground while driving or parked.
When the car drops, the height indicator (on dash) remains in the one
position and does not respond the height switch. If indicator reads
"HI", indicator will continue to read HI even with switch in normal.

The ON/Off switch in the truck seems to have no effect when the car
drops

I have noticed a hissing noise coming from the driver rear tire on
those instances when the car is dropping after parking. The ride may
come right back up when the car is started.

At this point the suspension is unreliable and I need to make a
decision. Should I continue to replace the bad air suspension parts or
go with a non-air aftermarket suspension system. I have replaced one
rear unit.

Thx
Chip L

"Chip L" <chiplong RemoveThis @hotmail.com> wrote in message
news:1155132082.637099.70520@i42g2000cwa.googlegroups.com...
> 1990 LS400 250,000 mi - electronic air suspension
>
> I realize the electronic air suspension is an issue on early LSs. I
> have replaced one air unit (rear) a few months ago. The car performed
> well for a few months but now the suspension is acting up.
>
> The car will hold the suspension correctly for several days/weeks and
> ride great. The suspension will (ususally) be at the same height when
> left parked overnight.
>
> But the car may drop in the rear to the ground while driving or parked.
> When the car drops, the height indicator (on dash) remains in the one
> position and does not respond the height switch. If indicator reads
> "HI", indicator will continue to read HI even with switch in normal.
>
> The ON/Off switch in the truck seems to have no effect when the car
> drops
>
> I have noticed a hissing noise coming from the driver rear tire on
> those instances when the car is dropping after parking. The ride may
> come right back up when the car is started.
>
> At this point the suspension is unreliable and I need to make a
> decision. Should I continue to replace the bad air suspension parts or
> go with a non-air aftermarket suspension system. I have replaced one
> rear unit.
>
> Thx
> Chip L
>

I would try to find out where the hissing sound is coming from. The problem
could be as simple as a loose or leaky connection.
--

Ray O
(correct punctuation to reply)