You’re the man! Thank you! Ordered another 2 bottles for a total of 6 since you mentioned cutting it close with 4.
LX570 AHC “Basics” - Added as sticky thread for AHC Issues (9 Viewers)
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You’re the man! Thank you! Ordered another 2 bottles for a total of 6 since you mentioned cutting it close with 4.
2001LC
SILVER Star
Seems to me there was a screen under the quick release cap for breather tube in reservoir hose fitting. I pulled something out (without remove retainer bolt) to get a rather thin tube into reservoir hose and just siphon out the fluid and too fill. Either way screen or no screen I avoid removing clamped hoses when every possible to reduce chance of future leaks.
Going through reservoir hose at quick release is slower, as very thin hose just can't siphon or fill as fast as a larger. I got lucky first time in, as my siphoning hose settled in the bottom of reservoir sucking it dry first try.
I started siphoning with a very handy large syringe, then ran hose to catch can let siphon on it's own as I did other stuff.
Oh, old towel placed on tire made for a more comfortable and cleaner work environment. 
Alternative way to empty reservoir.
One can also drain reservoir by bleeding off some fluid, then starting engine, stop pumping at just the right time.
Here's how:
As fluid fills into a empty circuit just bled by pump running, reservoir empties. The trick is to stop pump before reservoir is empty and starts suck in air. One needs to have a light behind the reservoir and have reservoir clean, so fluid levels is easily viewed. Then watch very closely as reservoir empties. Once fluid near bottom (empty) of reservoir open the RR passenger door (or any door to stop pump) or kill engine to stop pump. Anyway you stop pump is fine, just make sure to stop before reservoir empties.
This method will leave some old fluid in bottom of reservoir. So either siphon out the remaining small amount. Or add back a little more fresh fluid than you bled out, raise vehicle by starting engine and repeat to wash out diluted old fluid.
Warning:
Make sure to do a dry run before bleeding with normal amount of fluid in reservoir. This is to insures door opening will stop the pump immediately and you have a good visual on reservoir.
You can start your bleeding with height control in any setting you like. The higher the setting the lower the reservoir level will be at and the more fluid will bleed out any given line/bleeder. If starting in "H", vehicle will travel down from greater height. No matter, it always stop lowering at same distance from ground. Don't get stuck under it.
Whatever height setting used to start with, never change to a lower height setting until job done. Doing so will push old fluid back into reservoir.
I've kind of played with the 100 series flushing many times, with help from @PADDO. He also tough me how to inspect fluid for particles and filter them out, which I find very often in high mileage rigs. It's these particticals that damage seals.
I've also played with different ways of flushing. They're basically the same. With one exception. After bleeding the accumulator and a globe at same time in the 200 series, the system didn't want to pressure up. Light came on and pump would not run as mentioned earlier in this thread. I don't know if accumulator being bleed or bleeding both at same time caused this, as didn't happen with bleeding one globe/shock at a time. Rather than keep starting and stopping engine and waiting for fluid to works its way to sensor. I hooked up to Tech stream and activate the pump, it (AHC) took over right away filling system.
Going through reservoir hose at quick release is slower, as very thin hose just can't siphon or fill as fast as a larger. I got lucky first time in, as my siphoning hose settled in the bottom of reservoir sucking it dry first try.
I started siphoning with a very handy large syringe, then ran hose to catch can let siphon on it's own as I did other stuff.
Alternative way to empty reservoir.
One can also drain reservoir by bleeding off some fluid, then starting engine, stop pumping at just the right time.
Here's how:
As fluid fills into a empty circuit just bled by pump running, reservoir empties. The trick is to stop pump before reservoir is empty and starts suck in air. One needs to have a light behind the reservoir and have reservoir clean, so fluid levels is easily viewed. Then watch very closely as reservoir empties. Once fluid near bottom (empty) of reservoir open the RR passenger door (or any door to stop pump) or kill engine to stop pump. Anyway you stop pump is fine, just make sure to stop before reservoir empties.
This method will leave some old fluid in bottom of reservoir. So either siphon out the remaining small amount. Or add back a little more fresh fluid than you bled out, raise vehicle by starting engine and repeat to wash out diluted old fluid.
Warning:
Make sure to do a dry run before bleeding with normal amount of fluid in reservoir. This is to insures door opening will stop the pump immediately and you have a good visual on reservoir.
You can start your bleeding with height control in any setting you like. The higher the setting the lower the reservoir level will be at and the more fluid will bleed out any given line/bleeder. If starting in "H", vehicle will travel down from greater height. No matter, it always stop lowering at same distance from ground. Don't get stuck under it.
Whatever height setting used to start with, never change to a lower height setting until job done. Doing so will push old fluid back into reservoir.
I've kind of played with the 100 series flushing many times, with help from @PADDO. He also tough me how to inspect fluid for particles and filter them out, which I find very often in high mileage rigs. It's these particticals that damage seals.
I've also played with different ways of flushing. They're basically the same. With one exception. After bleeding the accumulator and a globe at same time in the 200 series, the system didn't want to pressure up. Light came on and pump would not run as mentioned earlier in this thread. I don't know if accumulator being bleed or bleeding both at same time caused this, as didn't happen with bleeding one globe/shock at a time. Rather than keep starting and stopping engine and waiting for fluid to works its way to sensor. I hooked up to Tech stream and activate the pump, it (AHC) took over right away filling system.
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Appreciate it @2001LC
Not sure I’m personally concerned moving a hose clamp on an atmospheric vent that’s not liquid filled. If it’s like any of the other hose clamps in these trucks, it’s under a ridiculous amount of tension.
I will bleed accumulator and globes separately doing one at a time starting from the N setting. This way when the last bleed is done, I know how much to fill the reservoir too.
Laslty, I’m thinking of getting one of those quart bottle pumps with the tubing leads. If I put the longer hose on the suction hose, will that fit in the reservoir?
That’s what I’m thinking of using and just hand pumping the old fluid out.
I’m at 75k of highway driving on the stick fluid with no towing etc. You think that’s pushing it based on your experience?
Not sure I’m personally concerned moving a hose clamp on an atmospheric vent that’s not liquid filled. If it’s like any of the other hose clamps in these trucks, it’s under a ridiculous amount of tension.
I will bleed accumulator and globes separately doing one at a time starting from the N setting. This way when the last bleed is done, I know how much to fill the reservoir too.
Laslty, I’m thinking of getting one of those quart bottle pumps with the tubing leads. If I put the longer hose on the suction hose, will that fit in the reservoir?
That’s what I’m thinking of using and just hand pumping the old fluid out.
I’m at 75k of highway driving on the stick fluid with no towing etc. You think that’s pushing it based on your experience?
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2001LC
SILVER Star
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Thank you!!!
2001LC
SILVER Star
@PADDO suggested I flush new OEM shock before installing. Sure enough I found particles in brand new shock. One shock I had to flush once and was clear afterwards. But the other new OEM shock sourced at same time same Dealer needed flush seven times. This got me into inspecting fluid old and new from the ACH system
Here's a little trick for Inspected fluid before or and or after your done with flushing an driven for awhile:
Draw off a little from any bleeder. I like sample from accumulator it seem the dirtiest, but that's a pain to get-to on the 200 series. Fluid will be dark, so small sample is best for this test. Place the sample of fluid in a white plastic container. Then look through fluid to bottom of container, particles over 30 microns can be see with naked eye. Some use glass jaw with white paper under it, but that's to hard for me to see particles in. If you see practicals either flush or filter.
200K miles on this AHC system with no history record at Toyota of ever being flushed.
After first flush (not yet driven) raised and lowered a few times. Look at at what I found. No wonder I had to replace a shock, like sand in seal.
After three consecutive flushing. $$$$
First attempt to build a filter, a simple automotive painters filter.
I learned something else while flush the shock, they're double chambered. In that, as I collapsed the shock fluid came out. Then as I extended all the way out, more fluid come out. I mention this to point out; we don't get it all even on the best flushings. This is true of any fluid we flush. So the more often we flush the better in my book.
Before testing I use AHC H to L and change comfort setting repeated over time (not to rapidly in succession), and drive a few hundred or thousands mile. Then flush again isn't a bad thing. Do we need to do this second flush NO. Will it add to life of system seals, yes!
I use a transmission filter adapted to a 12V pump to filter fluid, others use a cotton T shirt to filter fresh fluid in system. After doing one system with 9 qts of new fluid and still had particles, I built this filter to save $$ just for fresh fluids.
Here's a little trick for Inspected fluid before or and or after your done with flushing an driven for awhile:
Draw off a little from any bleeder. I like sample from accumulator it seem the dirtiest, but that's a pain to get-to on the 200 series. Fluid will be dark, so small sample is best for this test. Place the sample of fluid in a white plastic container. Then look through fluid to bottom of container, particles over 30 microns can be see with naked eye. Some use glass jaw with white paper under it, but that's to hard for me to see particles in. If you see practicals either flush or filter.
200K miles on this AHC system with no history record at Toyota of ever being flushed.
After first flush (not yet driven) raised and lowered a few times. Look at at what I found. No wonder I had to replace a shock, like sand in seal.
I learned something else while flush the shock, they're double chambered. In that, as I collapsed the shock fluid came out. Then as I extended all the way out, more fluid come out. I mention this to point out; we don't get it all even on the best flushings. This is true of any fluid we flush. So the more often we flush the better in my book.
Before testing I use AHC H to L and change comfort setting repeated over time (not to rapidly in succession), and drive a few hundred or thousands mile. Then flush again isn't a bad thing. Do we need to do this second flush NO. Will it add to life of system seals, yes!
I use a transmission filter adapted to a 12V pump to filter fluid, others use a cotton T shirt to filter fresh fluid in system. After doing one system with 9 qts of new fluid and still had particles, I built this filter to save $$ just for fresh fluids.
I am doing this right now but cannot find the 5th bleed. Both sides look identical.
FinallyGotOne!
SILVER Star
I only found four on my LX570 and there were only four shown on the shop manual diagram. If I remember correctly there was a fifth on my LX470. Some of the procedures referred to in this thread were written for the LX470/LC100.
2001LC
SILVER Star
The 5th bleeder is on the accumulator. It's on DS under passenger seat area, between frame rail (up against) and propeller shaft. It has a cover that needs removing for easy access to the bleeder. IIRC the FSM doesn't have it listed in the bleed procedure.
I found it eventually. Appreciate it.
While the overall job is simple, I found it quite difficult to reach the rear bleeders. I also did not have the ability to pump out any of the old fluid so did a quadruple flush through one bleeder to get as much of the old out. I did not look close enough to see if that shield around the accumulator could be removed so I said **** it and just bled the bleeder without tubing.
Original fluid looked slightly maroon brown. Not the black that weve seen before. Overall not too bad but glad I did it. No real change in driving characteristics but the rear does seem a little more damped.
I’ll flush the whole thing again in 30k miles.
While the overall job is simple, I found it quite difficult to reach the rear bleeders. I also did not have the ability to pump out any of the old fluid so did a quadruple flush through one bleeder to get as much of the old out. I did not look close enough to see if that shield around the accumulator could be removed so I said **** it and just bled the bleeder without tubing.
Original fluid looked slightly maroon brown. Not the black that weve seen before. Overall not too bad but glad I did it. No real change in driving characteristics but the rear does seem a little more damped.
I’ll flush the whole thing again in 30k miles.
HELP!
Disclaimer: I am new here! I am a fairly experienced mechanic but new to Lexus. Probably did something stupid, so hopefully you guys can rescue me. My vehicle is a 2011 LX570.
I attempted an AHC flush. I read most of the tutorials and a video on youtube, and I thought I followed the instructions, but I am having an issue. When I start the vehicle to "repressure" the system (step 8 in PADDO LX470 instructions), the vehicle height does not raise back to the normal "L" height.
Here is what I did
1. Put vehicle in "L" height.
2. Vacuumed reservoir tank of dirty AHC fluid with mityvac 7201 fluid extractor. Recovered about 1.5 liters. Initially added 2 liters (and then 1 more to total 3 liters since this is about the volume I recovered from the reservoir and bleeders).
3. Bled all 5 bleeders, starting with accumulator, then Driver Front, Driver Rear, Passenger Front, Passenger Rear.
3. Started vehicle and the pump sounds like it runs for a while, then stops, but the vehicle height does not raise back to L.
I did not start the vehicle after bleeding each bleeder (which I'm wondering was a mistake - causing a low pressure sensor error?). I thought I was following PADDO's instructions and did not need to start it after bleeding each one. I read another tutorial from NTSAINT that said I should not have bled more than 6 ounces without starting. And if I did bleed too much it would require some kind of special reset? (I didn't read it close enough beforehand!).
What am I doing wrong? How do I get the system to pressure back up?
Other thread- AHC Fluid Change How To -- Need Input
Disclaimer: I am new here! I am a fairly experienced mechanic but new to Lexus. Probably did something stupid, so hopefully you guys can rescue me. My vehicle is a 2011 LX570.
I attempted an AHC flush. I read most of the tutorials and a video on youtube, and I thought I followed the instructions, but I am having an issue. When I start the vehicle to "repressure" the system (step 8 in PADDO LX470 instructions), the vehicle height does not raise back to the normal "L" height.
Here is what I did
1. Put vehicle in "L" height.
2. Vacuumed reservoir tank of dirty AHC fluid with mityvac 7201 fluid extractor. Recovered about 1.5 liters. Initially added 2 liters (and then 1 more to total 3 liters since this is about the volume I recovered from the reservoir and bleeders).
3. Bled all 5 bleeders, starting with accumulator, then Driver Front, Driver Rear, Passenger Front, Passenger Rear.
3. Started vehicle and the pump sounds like it runs for a while, then stops, but the vehicle height does not raise back to L.
I did not start the vehicle after bleeding each bleeder (which I'm wondering was a mistake - causing a low pressure sensor error?). I thought I was following PADDO's instructions and did not need to start it after bleeding each one. I read another tutorial from NTSAINT that said I should not have bled more than 6 ounces without starting. And if I did bleed too much it would require some kind of special reset? (I didn't read it close enough beforehand!).
What am I doing wrong? How do I get the system to pressure back up?
Other thread- AHC Fluid Change How To -- Need Input
2001LC
SILVER Star
You can't use the 100 series bleed procedure on the 200 series. You've really messed up. New AHC system about $50K
Just kidding!
My understanding system has a fail-safe for low fluid/pressure. Pump has shut down. Go into tech stream and use the test mode, active/test the pump. May need to do a few times.
Do one globe at a time. Start up letting pressurize. Then move to next globe should kept from happening again.
Just kidding!
My understanding system has a fail-safe for low fluid/pressure. Pump has shut down. Go into tech stream and use the test mode, active/test the pump. May need to do a few times.
Do one globe at a time. Start up letting pressurize. Then move to next globe should kept from happening again.
I don’t have tech stream but had same issue after flush. A couple of restarts and the system went back into neutral height.
Haha, you got me there!
How do I "go into tech stream and use the test mode" ? This requires a scan tool or cable/software? I'll start searching, but any shortcuts would be helpful! Thanks
If you don't have tech stream, try restarting a few times as previously suggested. I just did the flush but I did one side at a time and bled the accumulator last as well.
2001LC
SILVER Star
Tech stream is accessed by plugging into the vehicle system. How-To: TechStream In 5 Minutes
Try the start and shutting down repeatedly, with reservoir full.
Try the start and shutting down repeatedly, with reservoir full.
Yes you were supposed to bleed one then start it and let it return to normal height. Turn the truck off check the fluid level, Then bleed the next,...
If I had to guess doing it the way you did possibly it sucked air into the system? Will it raise if you try and make it? How is the leven in the res?
Fluid level in the reservoir is fine. I tried to make sure that no air could be pulled in. I had fluid in the reservoir whenever I started the vehicle. I also used a bleeder bottle when I bled the 5 bleeders to try to avoid pulling air in. But I guess it's possible
It will not raise even if I switch it from L to N level
AHC fuse? I’ve done my own fluid at 30k and 60k. Never had a problem with AHC after.
Dealer? 100k vehicle, $300 maintenance job??? If you don’t know what you’re doing take it to the professionals 
