Changing out the AHC suspension fluid? (1 Viewer)

[uHu]

Like this? http://shoptoolsshoptools.com/shopexd.asp?id=2040

Yes, but not for $37. And you don't need much leverage either. Better get a $ 3.70 one and grind it down. Could maybe even unscrew them with a chain-type or steel-belt-type oil filter wrench or similar.

 

[uHu]

Thanks uHu.

Could you elaborate on number 4, bleeding while keeping the resevoir full. Once you've let the pressure off to install the new sphere, would there be any more bleeding to do?

Also, do I need to order the back up ring and o-rings separately? Any chance you have part numbers?

Thanks!

After fitting the new spheres, there will be air in the system. This has to be bled out. Don't know about part numbers today. Got my spheres 2nd hand, complete with actuators. Just unscrewed them and used the old rings.

 

[uHu]

By the way, our LX passes the graduations on the resevoir test. It gets more than 12 from low to high. However, I am all but certain the rear spheres are gone, as the rear rides just like the front when the front spheres went.

12 grad's ??? You must have some lift!
Is the lift from low to hi more than 4 inches? If it's not like 6-7-8 " then I don't think your spheres are busted. What about the neutral pressure? Tells you if the coils are not doing their share of the job. Do you have any extra weight in the back?
What I'm thinking is that if the gas springs have to take too much of the load, the pressure in the spheres (and in the hydraulic) will be too high, and your "gas-spring-travel" will be too short, giving a bumpy ride.
If your coil springs are 6 years old, they are prolly pretty lazy. My 80 front springs where pretty slack after only 3 years / 60 k km.

 

[hkeller]

Yeah. 12 little hatch marks from low setting to high setting. I don't have any kind of lift. No extra weight either. However, when my front spheres went the front rode just like the back does now. There is just no downward travel in the rear suspension. I can't think what thay would be but the spheres.

 

[uHu]

keller,
how did this story end?
Was it the spheres, the coils, or maybe just the sensors or height adjustment?

 

[hkeller]

Sorry; that was my bad manner's for not updating.

We have replaced all four nitrogen filled shperes, which corrected the problem. Lexus stepped in for an out of warranty repair, which was very nice!!!! They paid for parts and I paid for Labor.

The system has been bled at least 4 time, with all of the related work done by Lexus and the two times I've done it. So, I am hoping any contaminated fluid that would have caused the membranes to break down has either been removed or diluted to the point it is no longer a concern? (I'm keeping my finger's crossed.)

I'll keep you posted on any developments. Are your repairs holding?

 

[uHu]

Yes, the 4 2nd hand spheres are still good, after more than a year.
Also my rear height sensor repair seems to hold up. That was a corroded sensor which I cleaned up and sealed up. Certainly better than new. Seriously.

 

[waynec]

I am flushing the AHC system on my LX470 (98) because some lube center employee put water in the AHC resavoir. Anyway, I drained all the old fluid from all 4 wheels, purchased a set of redesigned spheres from Keith (as posted above) and now I need to get the pump to activate and it won't. My manual states that the pump can not start due to air in the line and to follow procedure DI-51 1 (anyone have a copy of this procedure)?

And, a local repair shop says I need to reset the onboard computer error for the pump to kick in. - any experience with this?

Thank you

 

[waynec]

I am flushing the AHC system on my LX470 (98) because some lube center employee put water in the AHC resavoir. Anyway, I drained all the old fluid from all 4 wheels, purchased a set of redesigned spheres from Keith (as posted above) and now I need to get the pump to activate and it won't. My manual states that the pump can not start due to air in the line and to follow procedure DI-51 1 (anyone have a copy of this procedure)?

And, a local repair shop says I need to reset the onboard computer error for the pump to kick in. - any experience with this?

Thank you

 

[uHu]

To reset the DTC (Diagnostics Trouble Codes) of the AHC (and ABS codes as well), you short pins CG (pin 13) and Tc (pin 4) of your DLC3 plug, also known as the OBDII connector, under the dash. Then turn ignition on, and depress the brake pedal 8 times or more within 3 seconds.
The pins 4 and 13 are the ones closest to the center of the 16 pin plug, that have a connector in them, one in the top row (1-8) and one in the bottom row (9-16). Meaning you can see metal in the holes, as most of them are empty.
Have a look here https://forum.ih8mud.com/showthread.php?p=1390134&highlight=eureka#post1390134

 

[uHu]

To run the pump manually, do the "Active Test".

On the DLC3, connect CG to Ts (pin 3);
(See previous post. Pin 3 is just below pin 4, in the left row of Dandon's pic linked to above. Meaning pin 1 is in the bottom left corner in that photo. And pins 3 and 4 are the only two neighboring pins with metal in them)
Switch the ignition on;
Depress the "Down" button of the Height Select Switch 5 times or more within 5 secs;
Now the AHC "OFF" indicator will start flashing at 0.25 secs interval.

Then you can start the engine (or do it when you turn ignition on)
Set the shock-setting switch to "Comfort" (Also called the "Damping Mode Select Switch)

Then, you can raise and lower the front by using the Up and Down buttons of the AHC Height Selector.
To control the rear suspension instead, you hold down the "Height Control Off" switch simultaneously.

WARNING: Do not raise the vehicle higher than the "Hi" position.

Have fun.

 

[Texasoil]

replacement new suspension accumulators available

Just to let you guys know, I have finally worked out all the kinks is the design and manufacturing of new replacement accumulators for the Lexus-LX-470 and Land Cruiser height adjustable suspensions.

Please go to my on-line store at Activesuspensionsystems.com to see more and place orders. New shipment arriving this week.

In the last week I have corresponded with 3 more LX-470 owner who are having contamination and pump issues .The factory service procedure for the pump does not properly diagnose an 'air in pump' situation and just calls the pump 'bad.'

Impossible to bleed it without disconnecting the discharge line.http://images.ih8mud.com/images/smilies/ban.gif

 

[SWUtah]

I just plan on having the Lexus dealer service my AHC at the normal interval (60K mile service). If serviced by the book how long do these systems last without major $$$ repair costs???

 

[Dandon]

To reset the DTC (...)

Have a look here https://forum.ih8mud.com/showthread.php?p=1390134&highlight=eureka#post1390134

Uhu, that's very interesting informationyou provide here. Thanks.
BTW, you did a search in the forum for "eureka"?

 

[Jim_Chow]

I just plan on having the Lexus dealer service my AHC at the normal interval (60K mile service). If serviced by the book how long do these systems last without major $$$ repair costs???

My feeling is it should last quite a while if serviced properly. I'm thinking 60K is kind of long between fluid changes, as I think the AHC fluid absorbs water like brake fluid. The brake fluid is also spec'd at 60k, which is way too long. Here in AZ, I don't have any real problem w/ humidity and water absorption into the fluid, it's more heat. I had my AHC fluid changed last summer, plan to have it done every other year. Most likely, I'll have the dealer do it, partly due to the higher risk of injury from the vehicle dropping, plus if the AHC goes south after the warranty is over and the dealer has changed the fluid every 2 yrs, which is way more often than the spec, I might get more slack from lexus for any potential repair.

 

[SWUtah]

My feeling is it should last quite a while if serviced properly. I'm thinking 60K is kind of long between fluid changes, as I think the AHC fluid absorbs water like brake fluid. The brake fluid is also spec'd at 60k, which is way too long. Here in AZ, I don't have any real problem w/ humidity and water absorption into the fluid, it's more heat. I had my AHC fluid changed last summer, plan to have it done every other year. Most likely, I'll have the dealer do it, partly due to the higher risk of injury from the vehicle dropping, plus if the AHC goes south after the warranty is over and the dealer has changed the fluid every 2 yrs, which is way more often than the spec, I might get more slack from lexus for any potential repair.

That's a good point about like brake fluid. I thought Lexus wanted the brake fluid changed every 30K miles, for my 2004, also states 30K on the 2007 maintance guide.

 

[Jim_Chow]

That's a good point about like brake fluid. I thought Lexus wanted the brake fluid changed every 30K miles, for my 2004, also states 30K on the 2007 maintance guide.

You're right, I just checked and it's also 30K on my 03LX. But based on the fact that my PS fluid was toast after only 3 yrs and 49K, my conclusion is AZ heat is harsh on fluids, so one must change more often and use synthetic wherever possible. It just part of the cost of owning any car here. On the bright side, at least cars don't rust here.

Also engine belts don't last more than 45-50K. My serp belt was replaced during certification around 49K. Belts on my 4runner, which normally last 60K easily in So. CA, looked shot at 45-50K (OEM belts). Belts on my '01 honda w/ 32K mi are starting to look old. I expect one more year on them, max.

 

[Texasoil]

I now have NEW replacement accumulators for the LX-470 for lots less than Dealer price--should last longer and they are rechargeable. go to 'activesuspensionsystems.com'.

 

[Texasoil]

the suspension fluid is a low viscosity mineral oil--similar to power steering oil or engine oil. Brake Fluid is a glycol-ether, completely different. Brake fluid will attack the 'rubber' parts in the suspension system. Suspension oil will attack the 'rubber' in the brake system.

 

[hoser]

Hey Texas, can you explain to me the difference between your Damping Force Actuator and the Toyota OEM one and why it is better? Is it the actual membrane that gets torn/develops a hole or is the problem the way the membrane seals around the edges. This pic is taken from your site.