Can't Get it to Stay Up :)

[BigDingus]

I have an RX300 2007

The suspension slowly drops. Takes about 10 minutes. All four corners drop.

When I'm driving and I feel the suspention getting hard I change the height selection then back to N. The pump runs till it gains the proper height.

This cycle never ends.

If I leave the car for any time it drops to it's lowest. When I strat the car the pump won't run until I retart it a few times. (Been told that resets the ECU)

Only valve I havent touched is the one above the rear axle, but in the middle of doing that.

List of what I've done:

Checked and cleand all height sensors.

Checked all connections using soapy water.

Checked struts for air leaks.

Used smoke bombs for air leaks.

Used dye to check for leaks.

Replaced the sus ECU.

[The-Acre]

The RX can suffer with heavy corrosion at the top of the struts, have you checked there? 

[PCM]

All my 4 struts have, over time, been replaced.

( 3 under Lexus warranty. )

All the other components have been fine...

[BigDingus]

Thanks for helping guys.

Due to both of your comments I'm going to attack the struts.

I did have to replace a front strut due to rust, but due to access I haven't touched the others.

Let the fun begin !!!

[BigDingus]

Should have asked the question.

How do I search for a leak on the top of a suspention strut?

If I run pressure into it, the top will reposition back into the car.

Or am I being dumb?

[The-Acre]

To be honest I'm not sure of the setup on yours, although if it's very quiet you may hear air escaping.  I've just disposed of my air setup and fitted springs and I would say the ride is better.

[BigDingus]

So much trouble with air I'm looking at changing to spring.

[The-Acre]

51 minutes ago, BigDingus said:

So much trouble with air I'm looking at changing to spring.

If you do just do your research and avoid cheap coilovers.

[BigDingus]

Guy just to give you an update.

Removed the strut I had suspitions of. No reason I choose the one I did, just thought it was going down faster than the others.

Once removed, I got to removing the rust with a toffy hammer (Lexus you should be ashamed). There was LOADS of it.

Result. There was a unbelievably tiny pin hole.

Now for the repair.

Best way, I'm going to see if it can be welded and if not. An old fashined way. Screw with a rubber seal. 3rd option, replace it.

New one is around £800.

Thanks for the input guys.