No -- you have not damaged anything nor done anything particularly wrong. It just means that probably you have filled the Height Control Accumulator after raising the vehicle and then emptied the Accumulator by opening its bleeder valve. The only damage is the mess that is made if the discharge hose comes off the bleeder.
Your description of bubbles everywhere when bleeding means either that there is air throughout the system
OR that one or more 'globe' membranes are failing and leaking nitrogen which is now throughout the system. As
@suprarx7nut mentions, if ‘globes’ are failing, bubbles will be most obvious at the failed ‘globe(s)’. Would all four ‘globes’ fail together? Maybe yes, maybe no. Think about other wear items like conventional shock absorbers, tyres, brake pads, etc – when one is worn the others usually are not far behind. [Note: AHC 'shock absorbers' are way different to conventional shock absorbers, really are just hydraulic struts, and usually only fail when prolonged excessive AHC pressures overwhelms internal seals or when rust destroys them].
When the vehicle is lowered (and when the self-levelling function operates) AHC fluid moves from the ‘shock absorbers’ and the ‘globes’ back to the AHC Tank. So if the ‘globes’ are failing, ‘bubbly’ fluid arrives at the AHC tank and sometimes it can be observed there before the ‘bubbles’ eventually escape to atmosphere.
When raising LO to N or when raising N to HI, the solenoid valve opens at the front Height Control Accumulator which then discharges its fluid volume and pressure to the ‘shock absorbers’ to lift the vehicle. The AHC Pump then recharges the Height Control Accumulator. [Theoretically this takes around 15 seconds after raise completed for a new stock vehicle but practically allow 30 to 60 seconds for an old, heavy vehicle].
If the AHC Fluid in the tank contains entrained or dissolved gas or air, then that is sent by the AHC Pump to the Height Control Accumulator during recharge, and then when the Height Control Accumulator next operates, this polluted fluid is sent on to the ‘shock absorbers’ and to the fluid side of the ‘globes’.
Or during self-levelling, polluted fluid is sent by the AHC Pump directly to the ‘shock absorbers’ and the ‘globes’.
If the membranes in the ‘globes’ are failing, then more nitrogen leaks through the membrane into the fluid, and the situation progressively deteriorates.
The test of the overall condition of the four ‘globes’ is given in the first attachment. This test is meant to be done with AHC pressures in the FSM-specified range and is not reliable at other pressures. Nevertheless, it gives an idea of overall ‘globe’ condition, although it does not indicate problems with individual 'globes'.
The so-called 16 step test can give an idea of what is happening at each corner. See Pages 5 and 6 of the second attachment -- section 4 Damping Force Controlling Condition Check.
If the 'globes' are original, then after 21 years and 200,000 miles they are a long way past their best and in that case replacement 'globes' are in your near future. Best price for a set of four ‘globes’ at the moment seems to be around USD700 imported from Impex and landed in USA, usually much, much more from most Lexus and Toyota dealers. Suggest check prices for 2 x Front 491
41-60010 and 2 X Rear 491
51-60010 at
IMPEX JAPAN — online new genuine spare parts shop - https://en.impex-jp.com/ and at
PartSouq Auto Parts Around the World - https://partsouq.com/ -- see also plenty of posts on IH8MUD experiences with both of these suppliers.
Air can be a culprit, most usually entering the system when the AHC Tank is not kept topped up during the bleeding process and air enters the pump.
The other less frequent cause is air drawn past worn internal pump seals and o-rings. These can be replaced – parts cost only a few dollars. That may also be a wise time to replace the AHC Pump (not the whole assembly, just the pump and the seals – pump 48901-60010 at USD164.94 , seal 90311-10001 at USD4.28, o-ring 90301-06012 at USD2.34, o-ring 90301-70003 at USD2.31 – cross check these Partsouq prices with Impex and others and add delivery charges and cross-check local dealer prices).
If the AHC system is in reasonable shape (not overwhelmed by rusted pipes and fittings or damaged wiring harnesses and connectors), then these repair/replacements are good value if the comfort provided by the adaptive damping of the suspension is desired to be preserved, along with ability to select heights.
Replacing AHC hydraulic components always involves careful full bleeding of the entire system with new AHC Fluid to get rid of the air which has entered during parts replacement, and to purge any remnant nitrogen gas from previously failed 'globes'. Note that multiple bleeding efforts may be required -- the system is not "open" and cannot be fully flushed end-to-end like most brake systems. Air may remain trapped in 'shock absorbers', in long pipes or in the Height Control Accumulator. Persistence sometimes is necessary.
By the way, if you have not seen the third attachment it is worth a careful read, especially those parts which explain the function of individual components and how the AHC/TEMS hydraulic circuits operate in various conditions.
