Front and now Rear Suspension woes

DaKa · February 27, 2018

I've decided to keep my 2001 LS430 for another year, now my 12th year of ownership.

However, I may regret this decision as while treating it to some new rotors and pads on the front today seems to have caused a suspension problem that I've seen a few threads about.

In short, I jacked the whole front of the car up both sides at once , it took a while to complete the replacement of the pads/rotors as I took the 2 wheels once removed to have new tyres fitted and also stopped for lunch, so it was probably off the ground for 3-4 hours.

Fitted everything required and also bled the front brakes a little with the help of my wife. A bad idea perhaps, as when I asked her to push the brake pedal down, she did it like an emergency stop and my bleed line connections popped off and fluid shot everywhere inside the front offside wheel arch. I mention this because having bled both sides a little (at no point was the brake fluid reservoir below minimum) when the car was dropped back down, the front suspension dropped completely - much too low.

It had been on the 'high' setting with 'sport' selected, with no previous problems noticed. I regularly change the car for normal to high and switch the sport setting on/off.

I'm asking here if jacking to car up and leaving it for too long (and perhaps the very cold weather) has highlighted an issue with my air suspension, or, has bleeding the front brakes badly been a factor?

I presume that the air suspension system has nothing to do with the braking system and that it is merely a coincidence? Although I seem to have introduced some unwanted air into the brake system that will mean bleeding them all again.

When the car was first lowered it seemed to be just the front suspension affected, but having jacked the car up and lowered it again, it now seems that both the back and front are much too low.

I'm going to read the related posts now, but if someone could just confirm that the brake replacement work today has not directly caused the suspension issue e.g. it was only the action of jacking the car up/down that affected some of the suspension seals or whatever else may have gone wrong on what is now an old car?

Thxs

DaKa · February 27, 2018

The Lexus Gods have looked favourably upon me.

After a couple of hours and reading the various posts regarding the horrors of air suspension, I started the car up again and ran it for a short while.

My suspension is now back to normal front and back, but obviously there is something not quite right.

It strikes me reading the posts that nothing on my car has broken, but that perhaps the accumulator is not keeping or gathering the air pressure needed as quickly as it should, or perhaps a slight leak?

If some of the learned members familiar with the suspension system could confirm if there are any cheap seals or bushes that I can replace it would help. I refer particularly to the post containing pictures or how to access things once the o/s/f inner wheel arch panel has been removed and the part number specified - I'll add that link in a moment.

DaKa · February 27, 2018

Here is the post that I found very useful:

http://www.evansweb.info/2009/11/23/ls400-ride-height-sensor-repair/?utm_source=LexusOwnersClubUK&utm_medium=ForumLinks

DaKa · March 1, 2018

Just to add that I believe the suspension problem was perhaps in part caused by starting the car while it was jacked up at the front in order to bleed the brakes. I jacked it up using the front suspension arms that connect to the front hubs rather than the jacking points near the front doors. I've done this before but typically one side at a time and would not have started the engine while up in the air, I also lifted the car more than required with the tyres clear of the ground about 5 inches - I'm guessing that it may have confused the self-levelling sensors?

Indeed, there was no need to run the engine as the foot brake pedal alone without the servo would have been more than sufficient for bleeding purposes.

I'm now a little worried about changing the pads/rotors on the back, but will do it one side at a time and quickly.

DaKa · March 5, 2018

P.S.

Having replaced my LS430 2001 front rotors and pads, the job wasn't really needed as the pads were only say, 20% worn and the discs had minimal wear.

Before I put the old pads and rotors in the metal bin at my local recycling centre, if there is anyone nearby that wants them they're very welcome to collect from CM13.

send me a PM before end March by which time I will have thrown them.

GrahamG · March 6, 2018

Damien,

I am not an expert but have read more than one post that advises against running the engine while the car is jacked up and I believe there is a warning against doing so in the manual. This because of the air suspension but I do not know of anyone experiencing any damage, just the problem you had.

I would advise you to use the official jacking point on the chassis and certainly not a suspension arm.

DaKa · March 6, 2018

Noted and thanks Graham, I'm getting careless in my old age.

It makes complete sense not to do what I did and clearly confused the height sensors - I don't know why I thought to start the car in order to bleed the brakes, it wasn't needed and I certainly won't be trying that again!