Quick question; wouldn't it be better to fill the globes with fluid just prior to fitting ?
LX570 AHC Globe/Accumulator Replacement (40 Viewers)
- Thread starter NKP Garage
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
There is no space to fill the globes with fluid until they are pressurized.
- Thread starter
- #63
Yup! No point trying to fill them with a few drops. There's not much room in there. And any air will come out during bleeding anyway.
Okay thanks, good information as I have two fronts to do as well.
FYI the rear dropping after freeway is normal. The truck raises the rear above a specific speed to improve fuel economy. You’re just noticing something you don’t usually.
The reservoir on the 200 is comically oversized. There will only be fluid visible between those marks on the lower right side of the reservoir. You can easily illuminate the upper portion of the tank and it not show the fluid. My suggestion is to get a helper, drop the spare and have them put a light right against the side of the tank angled down a bit until you can see it.
The reservoir is only very slightly pressurized. Bleeds are very easy to do with just a 10mm a piece of 3/16 id tubing (1/4 will work but you have to hold it on) and any old water bottle. I drill a hole in the cap and run the tube in. I wouldn’t recommend a bleed until you’ve verified the fluid level and added a bit. A full fluid change makes a noticeable difference in ride characteristics
Very interesting post; you did a fluid change prior to this you said and I was wondering if you could run through what you did ? I have a 4.5 v8 diesel which I think in UK spec suspension wise the same as US LX570 (?). The 4x bleeds front/rear are obvious but I'm struggling with the main accumulator bleed in terms of finding it and/or bleeding it.
I've pasted two pages from the service briefing I have below; I'm assuming the main accumulator bleed is the Suspension Control Pump Accumulator Assembly in the two diagrams. There is also a bit in the text about how the L-N N-H shift uses fluid from the SCPAacc only if its at pressure. I'm guessing this is important when doing a fluid flush as there must be a lot of fluid in there ?
I've also attached the service pdf. No idea where I got it from but its quite a useful document on AHC and KDS.
Thanks, sorry to be a pain but better to ask !
I've pasted two pages from the service briefing I have below; I'm assuming the main accumulator bleed is the Suspension Control Pump Accumulator Assembly in the two diagrams. There is also a bit in the text about how the L-N N-H shift uses fluid from the SCPAacc only if its at pressure. I'm guessing this is important when doing a fluid flush as there must be a lot of fluid in there ?
I've also attached the service pdf. No idea where I got it from but its quite a useful document on AHC and KDS.
Thanks, sorry to be a pain but better to ask !
I used the procedure linked at the bottom of my post.
Be sure to read the entire thing before beginning. Look at all the pictures to familiarize yourself. I’ve done multiple flushes at this point, and I do not personally recommend bleeding the 5th accumulator. Multiple bleeds on the other 4 work just fine to completely flush the system.
NEVER let the reservoir run dry. It’s a pain to get the system bled properly.
If you wish to bleed the 5th, it’s on the drivers side, near the center of the back door, right next to the muffler. There is a cover plate held on by 3 12mm bolts. Mine required a breaker bar to loosen. Make sure the truck is cold before removing the cover, the muffler can be very hot. I got very little fluid from the 5th accumulator.
Overall it’s a very simple job, as long as you are careful to avoid introducing air into the system.
Last edited:
Why not bleed the 5th?
After only bleeding the 4 my truck's suspension felt terrible. I did the 5th and it made a huge difference.
After only bleeding the 4 my truck's suspension felt terrible. I did the 5th and it made a huge difference.
It can cause low pressure sensors to trip, disabling the pump. Which then needs to be manually run via techstream. This is why the dealers don’t bleed it as part of their normal procedures. Multiple bleeds of the other 4 accomplish the same thing without the additional hassle
By all means bleed it if you have TS and are trying to save some time.
Thanks for reply; got on with it (while you lot were in bed on the other side of the pond !) as I had some spare time. As you say very simply process and no issues. I agree with you about just using the four bleeds on the wheel accumulators; they are the end point and the main lift accumulator is only there to discharge its contents to take the pressure off the main pump during lift from L-N or N-H. I flushed the tank then bleed each corner, lifting the vehicle back to L-N after each bleed once the system had reached pressure (pump stopped) so that the lift acc discharged each time. I had fresh fluid very quickly. Job done. The only issue was seeing the tank level with was tricky but luckily I hit on a solution involving insulation tape, stick and torch (don't ask !).
Thank you for your help and your posts which have been very useful.
[/QUOTE]
Thank you for your help and your posts which have been very useful.
[/QUOTE]
Forgot to mention that on road testing after fluid change I was staggered at the amount of degradation in the suspension system that old fluid causes. It seems extraordinary that this isn't a dealer supported service item.
[/QUOTE]
[/QUOTE]
Ok, you got an actual “HA!” out of me.
Thinking about this a bit having done the flush as to exactly which route the fluid takes as you bleed the system. I was wondering how much old fluid remains after the process.
There is a case for saying that you are better to have the car in L as the Levelling Valve remains closed when the ECU signal isn't received to raise or lower the car and the closed parts of the system (shocks and front relief chambers) are as empty as it is possible to be.
Bleeding at the front Damping Force Control Actuators on both sides the fluid that comes out is coming front the two front shocks and from the two Relief Gas Chambers on both sides. The Levelling Valve is shut so no fluid can come via the Height Control Valve or the rest of the system. ( the front drops slower while bleeding than the rear which doesn't have the Relief Chambers. I noticed that most of the old fluid came from the first front bleed as both sides are linked via the Height Control Valve and having raised the car back to L-N-L before doing the second front very little old fluid came out of the second front bleed which makes sense.)
Having bled the front or rear bleeds the fluid then comes via the Levelling Value when the ECU allows it to open as you start the car. Going from on the stops to L refills the Relief Gas Chambers and front or rear Shocks; then going from L to N discharges the fluid within the Suspension Control Pump Ass ( it was noticeable that the front took a lot longer to lift after bleeding than the back did which again makes sense as its filing not only the shocks but also the two large relief chambers which will have completely discharged their pressure as they are nitrogen filled accumulators as well)
The rear No.1 Gas Chambers are directly attached to the shocks with no relief chambers so they bleed out less fluid and the back drops very quickly when this fluid is released.
In effect the bleed fluid only comes from the shocks and front relief gas chambers so while the rest of the system is completely purged with new fluid, when the levelling valve opens as you start the car and engage the pump to replace the lost fluid, the shocks and chambers are really only rinsed as some old fluid will remain as they are a closed system. Quite how many "rinses" you need is anyone's guess but from what I observed one rinse seemed to remove the vast majority of the fluid.
I can also see one major possible cock up in this. If you had raised the car from L-N and then switched off the car before the pump had been able to recharge the Suspension Control Pump Acc Ass completely THEN bled the shocks you are then completely reliant on the pump to not only recharge the SCPAA but also the two front relief chambers and the shocks (which is a big ask) and will take some time. It can take up to 14 seconds to raise the car with a charged system, with a completely discharged system it could take far longer. I have read posts from people who got ECU errors during the process and this might be a possible reason why.
I hope this makes sense and its very much in line with your notes which have been very helpful; I'm sure I've missed something !
[/QUOTE]
There is a case for saying that you are better to have the car in L as the Levelling Valve remains closed when the ECU signal isn't received to raise or lower the car and the closed parts of the system (shocks and front relief chambers) are as empty as it is possible to be.
Bleeding at the front Damping Force Control Actuators on both sides the fluid that comes out is coming front the two front shocks and from the two Relief Gas Chambers on both sides. The Levelling Valve is shut so no fluid can come via the Height Control Valve or the rest of the system. ( the front drops slower while bleeding than the rear which doesn't have the Relief Chambers. I noticed that most of the old fluid came from the first front bleed as both sides are linked via the Height Control Valve and having raised the car back to L-N-L before doing the second front very little old fluid came out of the second front bleed which makes sense.)
Having bled the front or rear bleeds the fluid then comes via the Levelling Value when the ECU allows it to open as you start the car. Going from on the stops to L refills the Relief Gas Chambers and front or rear Shocks; then going from L to N discharges the fluid within the Suspension Control Pump Ass ( it was noticeable that the front took a lot longer to lift after bleeding than the back did which again makes sense as its filing not only the shocks but also the two large relief chambers which will have completely discharged their pressure as they are nitrogen filled accumulators as well)
The rear No.1 Gas Chambers are directly attached to the shocks with no relief chambers so they bleed out less fluid and the back drops very quickly when this fluid is released.
In effect the bleed fluid only comes from the shocks and front relief gas chambers so while the rest of the system is completely purged with new fluid, when the levelling valve opens as you start the car and engage the pump to replace the lost fluid, the shocks and chambers are really only rinsed as some old fluid will remain as they are a closed system. Quite how many "rinses" you need is anyone's guess but from what I observed one rinse seemed to remove the vast majority of the fluid.
I can also see one major possible cock up in this. If you had raised the car from L-N and then switched off the car before the pump had been able to recharge the Suspension Control Pump Acc Ass completely THEN bled the shocks you are then completely reliant on the pump to not only recharge the SCPAA but also the two front relief chambers and the shocks (which is a big ask) and will take some time. It can take up to 14 seconds to raise the car with a charged system, with a completely discharged system it could take far longer. I have read posts from people who got ECU errors during the process and this might be a possible reason why.
I hope this makes sense and its very much in line with your notes which have been very helpful; I'm sure I've missed something !
[/QUOTE]
Last edited:
[/QUOTE]
That all looks right to me. I just finished re reading the doc you posted. It confirms what I worked out the hard way on how the system works. I need to get back under the truck and look, as I haven’t yet laid eyes on the center suspension control cylinder sub assembly or the relief gas chambers. I’ve had my hands on all the rest of them.
Thinking about it, I can see the value in bleeding the 5th accumulator, as that fluid is essentially trapped within that part of the system. It’s probably not a big deal, as it will eventually fully mix with the fluid coming from the pump and within the height control valve. Considering you can’t actually change out 100% of the fluid due to the system design, I understand both why the 5th accumulator has a bleeder, and why Toyota doesn’t use it as part of the fluid replacement procedure. Once you’ve replaced 80-90% of the fluid in the system, you’ve achieved what the system performance specifications call for. Just another one of those ‘within spec’ things car dealers tell us that drive car lovers batty.
Just try not to spill too much of that fluid. It sticks on everything.
I think I spilled almost a full liter between pump testing and bleeding.
fyi, here’s what my old fluid looked like
Hi, no problem, its a very interesting read on the suspension although it's a bit worrying how complicated the system actually is. I was going to swap out the front accumulators but having done a fluid flush the suspension is so much better; I'm going to leave the new accumulators off for now. Only done 90k miles and they seem fine. My old fluid wasn't that bad, just discoloured with no sign of any gas bubbles in it from a possible broken or leaking accumulator.
On your picture of the old fluid is that bubbles in the top of the bottle or just how the light is shinning through on the top ? I read a bit about fluid issues on the 100 forum from a guy call @PADDO I think which was very good on fluid condition and AHC issues. Worth a quick search and read I learnt quite a bit looking through his posts.
Say hello to Dolly will you if you see her, love her in Scotland !
On your picture of the old fluid is that bubbles in the top of the bottle or just how the light is shinning through on the top ? I read a bit about fluid issues on the 100 forum from a guy call @PADDO I think which was very good on fluid condition and AHC issues. Worth a quick search and read I learnt quite a bit looking through his posts.
Say hello to Dolly will you if you see her, love her in Scotland !
You are correct, they are bubbles. This was after one of my first bleeds when I was troubleshooting the system. It does indicate a bad globe, but the system is currently performing well within spec. So I’m not gonna mess with it for now.
My girlfriend is a musician/songwriter. She has written songs for Dolly and met her on multiple occasions. I keep asking her when do I get to meet her!?
My girlfriend is a musician/songwriter. She has written songs for Dolly and met her on multiple occasions. I keep asking her when do I get to meet her!?
bloc
SILVER Star
I suspect the fluid exiting the bleed port at such high speed introduces turbulence that causes air entrainment.. I bled my friend’s AHC system lately and each screw had air which eventually separated out. System works great, no bad accumulators as far as we could tell.
