I checked pressures before I get into the other items. The front and back were both good, especially since I adjusted he torsion bars, but now after I replaced the globes my back shows normal for a while, equal to front pressure and then drops down to 2.5.
Did I not tighten the bleed valves? globes? Don't see much of a leak but granted it sill was pretty oily from the install. anything else that can drop the pressure on rear?
View attachment 2355708
I will leave it to more experienced Members to diagnose your inconsistent rear AHC pressure reading.
If the measurement is reliable, it would suggest that the rear of the vehicle is too low -- meaning too much weight is being carried by the springs and not enough by the rear AHC system, or, perhaps something is binding mechanically (rear control arm bushes?), or, there is some other problem.
However, unreliable readings are experienced from time to time, so the first step is to take more readings.
In my own case, I have had similar but unreliable readings from time to time and wondered whether something is not working properly. Usually, I drive around the block to settle the suspension (and myself!), return, remeasure the physical hub-to-fender heights (both at static cross-level with engine and AHC "OFF", and, also functional physical hub-to-fender heights with engine and AHC "ON") to make sure that there is nothing ‘hanging up’ due to poor bushes or whatever. Then I reconnect my measuring equipment (in my case Mini ELMscan327 dongle plus reader app on an Android tablet) and very carefully drop to "LO", raise to "N", making sure that the pump has finished recharging 'globes' and Height Control Accumulator, and then check one more time that functional hub-to-fender heights are as expected, then read pressures. I usually persist until I have three measurements that are consistent. In my case, this usually persuades me that the "something not working properly" probably is me rushing too much!
In your case, if highly variable AHC pressure readings are obtained consistently while following the correct procedure and with hub-to-fender heights correct and weight correct, and if satisfied that there are no mechanical problems such as the rear upper and lower control arm bushes, then it may be time to consider the next level of possible problems.
The area around the ‘globes’ and Damping Force Control Actuators are likely to be be wet after changing ‘globes’ but, given the pressures involved, if you had a leaks at the ‘globes’ or bleeders, you would not be in any doubt from AHC fluid dropping to the floor. (Nevertheless, globes and bleeders should be tightened to the FSM-recommended torques but not overtightened. By the way, OEM ‘globes’ normally are supplied with two special washers fitted to each ‘globe’ as shown in the FSM – or look at the relevant Partsouq parts diagram).
A consideration might be whether the AHC time for "drop from N to LO" is significantly longer than the 3 to 8 seconds mentioned in the FSM, and, whether the AHC time to "raise from LO to N" is significantly longer than the 10 to 15 seconds mentioned in the FSM (with the Height Control Accumulator fully charged and in the stored state), and, whether any DTC’s are showing up such as DTC’s C1751 or C1762 (which may indicate pump problems or blockages). See half-way down my post #39 in this string for a link to a post by uHu on this topic.
If these kinds of issues are real, then it all starts to become complicated and expensive, so it is best to ensure that the ‘simple’ things are in good order first.
Hopefully other IH8MUD Members are able to give further guidance.
(bad Toyota)
