landcruiser 100 ahc suspension fluid change

[kapil]

dear all , i recently bleeded the accumulator with all the ahc fluid and replaced it with the original toyota suspension fluid , the fluid that came out of the accumulators was white foamy liquid. however even after using 2 jericans 2.5 litres of the fluid the liquid that comes out is still foamy and the front shocks are like as if they don't exist. its a very very bumpy ride . please help.
the height control is responsive immediately when i increase or reduce the height it works . are the spheres ok ?

 

[PADDO]

Doesn't sound very good, do the Low to High test. Put it in low, mark the fluid level on the reservoir and then raise it to high and mark the level. Count the number of graduations. Anything less than 7 (or 8 depending on the origin market of your vehicle) says all four spheres are unserviceable. You can also put the AHC system into test mode and step through the 16 damping steps to try and isolate a particular corner. But if you've put 5 litres of fluid through, it's foamy still and the fronts are rock hard I suspect you have a problem.
This low to high test requires that the neutral pressures are in specification to be truly accurate.

 

[kapil]

dear sir , i did the low and high test , and the graduation is at 6 from low to high . have a feeling that the system is not properly bleeded . the problem started by the service helper at the petrol station mistakenly put water in the suspension fluid box . why would the liqiud be foamy ? i was reading an article on hydraulic systems and a bubbly foam could be as a result of air been incorporated in the system . could it be possible that the front suspension has packed up ?

 

[kapil]

how do i run the ahc test mode ??

 

[kapil]

can the front speed sensor be damaged ? and thus causing this problem?

 

[uHu]

Pretty sure your spheres are toast, at 6 grad's. That explains the lack of suspension. The foam can be nitrogen leaking through a broken sphere membrane.

You better get all the fluid changed. With water in it, the pump will whip cream.

 

[PADDO]

dear sir , i did the low and high test , and the graduation is at 6 from low to high . have a feeling that the system is not properly bleeded . the problem started by the service helper at the petrol station mistakenly put water in the suspension fluid box . why would the liqiud be foamy ? i was reading an article on hydraulic systems and a bubbly foam could be as a result of air been incorporated in the system . could it be possible that the front suspension has packed up ?

If you know water was inadvertently added to the reservoir then you'll most likely need to remove and drain residual fluid from all four shock actuators and comprehensively bleed the system from all five bleed points until you have eliminated the foaming. You need to get all of the water out because it will induce rust and other problems, particularly if what was added had washer fluid or other chemicals in it. One of the reasons it is foaming is because when you relieve pressure off a pressurized liquid the gases in the liquid expand and bubble, same principle as when you open a beer or a bottle of soft drink. Also if the water had any detergents or surfactants in it that changes the surface tension and properties of the mineral oil based AHC fluid. If you search the phrase "16 step test" or "damper accumulator test" you will find posts by me that outline what to do: basically short Ts and E1 in the DLC1 connector (under the hood) with the engine running and each time you step on the brake the damping setting steps one, from soft to hard. This is for an obd11 vehicle, not sure what you have. I don't think a broken speed sensor is causing this problem.

 

[kapil]

dear all ., my lc 100 is 2004 model amazon , is there any way you can check which accumulator is damaged ? i have managed to secure 2 accumulators from the budget i had ,

 

[PADDO]

There are three things you can do to check the serviceability of the globe accumulators:
The low to high test - yours failed at 6 grads, so, according to Toyota you need four new globes.
Another check, in an attempt to isolate the worst globe(s), is to do the 16 step test where you simply identify the least damped (hardest) corner(s). This will also identify if a damper actuator valve assembly isn't responding to its ECU orders. These assemblies are known to fail too and can appear like you have a failed accumulator on that particular corner.
And finally you can remove each globe and inspect if the diaphragm is intact. If the globe is full of fluid (hundreds of mls) and the diaphragm is not tight and hard but can easily be depressed with the blunt end of a pencil or similar then it's completely U/S.

At 6 grads and with known contamination in your AHC fluid I'd recommend remove/drain/refill/reinstall the four shock actuators, followed by good system flush through with new fluid, install four new globes (fronts are smaller than rear and have different part numbers) and re bleed. Check and adjust neutral pressures to finish the job properly.

If you can secure new globes from a source like Amayama and can locate a Toyota/Lexus dealer or mechanic experienced in AHC repair (or willing to learn and do it yourself) then the all up cost won't be too bad. If repairing your AHC is too hard and you don't consider it worthwhile then you might consider ripping it out and installing conventional shocks, coils and torsion bars.

 

[kapil]

Dear Sir ,
my lc100 is still having huge problems , i have changed my pump since the pump wasnt pumping enough bar pressure , replace all 4 spheres yet the rear is droping when the car is switched off . what could be the problem ? when i put the car on high then the rear goes up alot , and the gap between the low and high test is almost 10 . when driving the car the rear keeps adjusting upwards every 2 minutes and the ride is still bumpy

 

[kapil]

could it be the second hand spheres are replaced could be faulty ?

 

[PADDO]

Dear Sir ,
my lc100 is still having huge problems , i have changed my pump since the pump wasnt pumping enough bar pressure , replace all 4 spheres yet the rear is droping when the car is switched off . what could be the problem ? when i put the car on high then the rear goes up alot , and the gap between the low and high test is almost 10 . when driving the car the rear keeps adjusting upwards every 2 minutes and the ride is still bumpy

Sounds like you are describing a height sensor problem and/or a lot of air in the system.
Height dropping by itself when the vehicle is turned off could be caused by internal leakage in the rear shock actuator circuit. If it's not holding its pressure it will lower under the force of gravity. A very small drop in height over a period of time (overnight) is not unrealistic or an indicator of a fault but a big drop in a short period of time suggests internal leakage to me.

 

[PADDO]

could it be the second hand spheres are replaced could be faulty ?

Obviously the used spheres could be faulty, but they just affect damping not ride height. If the height is resetting itself and behaving randomly then you need to confirm your height sensors are serviceable and their connections are secure.
Did you do the 16 step damper actuator test?