LEXUS RX300 AIR SUSPENSION CONVERSION

[9099shane]

Hi i have a 2004 Lexus Rx 300 that i would like to convert from air suspension to shock absorbers and springs and wondered if anybody has a list of the parts required please or could recommend a conversion kit, thanks in advance for any help my regards shane.

[The-Acre]

1 hour ago, 9099shane said:

Hi i have a 2004 Lexus Rx 300 that i would like to convert from air suspension to shock absorbers and springs and wondered if anybody has a list of the parts required please or could recommend a conversion kit, thanks in advance for any help my regards shane.

Do a search for BrightonRX300 and you should find his post on the conversion he did last year.

[9099shane]

I Have taken a look and it looks like a good conversion, but would like to compare with the option of using standard RX suspension components from a non air suspension model if anybody has a list of whats required that would be great thanks for the reply The-Acre .

[The-Acre]

On 2/26/2019 at 4:40 PM, 9099shane said:

I Have taken a look and it looks like a good conversion, but would like to compare with the option of using standard RX suspension components from a non air suspension model if anybody has a list of whats required that would be great thanks for the reply The-Acre .

No replies yet I see.  As far as I'm aware there probably isn't much else that's needed. You would have to disable the height warning light on the dash. The compressor can be left in place with the fuse removed and the height sensors disconnected. I've considered what I would do should I be unfortunate enough to have suspension problems and I think I would go for direct replacement struts from Strutmaster in the US if I can manage to get a reasonable shipping rate. The parts are a direct fit and cost around £800 for the four. It may be worth enquiring with them.

[Neil E]

I agree with Phil's summary above. Simply replace the struts with new Lexus RX300 non-air struts in each corner. Unplug all air system components and then it's a case of eliminating any error codes and warnings.

I wouldn't consider swapping from air unless there were several failures of the system but that wasn't the question. Has your air sus failed or do you just not like it?

[9099shane]

Air suspension has failed and is stuck in the full height position and looks to be a problem with the compressor as the car is getting a lot older now and likely to have other suspension faults in the future i thought it may be worth looking at putting shocks and springs on and thought from what i managed to find out you could use standard shocks and springs from the non air suspension Rx models but i have been able to find out anymore info such as part numbers etc so i may have to go with coil-overs unless there are any ideas on what may be causing it to stay up full height.

[The-Acre]

25 minutes ago, 9099shane said:

Air suspension has failed and is stuck in the full height position and looks to be a problem with the compressor as the car is getting a lot older now and likely to have other suspension faults in the future i thought it may be worth looking at putting shocks and springs on and thought from what i managed to find out you could use standard shocks and springs from the non air suspension Rx models but i have been able to find out anymore info such as part numbers etc so i may have to go with coil-overs unless there are any ideas on what may be causing it to stay up full height.

It may just be a height sensor issue. Has the ride become hard or is the suspension still ironing out the bumps? I don't know what the RX300 equivalent is in the US but Rockauto have struts with springs for about £75 each. Someone here must be able to give you the part numbers.

[9099shane]

the ride has become solid so you just bounce when hitting a bump, i will recheck the sensors but couldn't find any faults before. thanks for the replies its appreciated.

[The-Acre]

6 hours ago, 9099shane said:

the ride has become solid so you just bounce when hitting a bump, i will recheck the sensors but couldn't find any faults before. thanks for the replies its appreciated.

Unfortunately, unlike conventional coil spring suspension, the air system is very complex.  To try to diagnose a problem via a forum doesn't always bear fruit. The fact that it's at full height maybe suggests the struts are holding air. A faulty sensor can play havoc on the system.  I wish I could offer more.

[Neil E]

Okay, the fact that it is up in the air means the struts are holding air and the pump put the air into them so its probably fine. 

The most common fault with air-sus is the height controllers. Check to see if one corner in particular is higher than the others? 

On level ground, set the height level to the middle setting on the switch and measure the gaps between the wheel arches and the tyres. If one side is higher than the other, it's very likely to be the height controller on that high corner that is faulty. The other way to check if it's high on one side is on a level road the car will pull to one side.

If the suspension goes down and stays down that points to a leaking strut but if they are all 'up' then it seems your struts and pump are fine. 

New height controllers are about £200, they are quite small items and very easy to fit. You might try to source a good one from a breaker for a lot less but it's a risk. They can sometimes be taken off, cleaned or freed up again if they have just seized up through dirt ingress. 

 

[9099shane]

The suspension doesn't drop no matter what you do with the switch i will recheck the ride height sensors today, thanks for the replies.

[BachelorDays]

Thing that bugs me in all this is the bumpy ride if the struts are on max height and filling properly with air. If they are full of air shouldn't that cushion the ride?

There's no mention of how recently and how gradually all this has happened.

Let's see what your investigations on the sensors reveal. Do have a good look at the condition of the struts as well (rust etc).

[Neil E]

No it won't cushion the ride. If one or more of the struts is high, the ride will be very bumpy. 

It's like having very stiff suspension on a high setting.