yeah, I checked the fuses. I made an appointment at the local 4x4 shop but they can't get me in until 7/22 so maybe I'll figure it out by then. I may try disconnecting the battery hoping that will reset something.
replacing AHC globes/accumulators (1 Viewer)
- Thread starter pete100
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Weasel06
SILVER Star
Here's an update on my experience with the globe change as I did run in to something that I don't believe I've seen mentioned yet. I was lucky that my globes came off fairly easily using the borrowed fan clutch wrench set from O'Reilly. I bled all globes after install and everything seemed fine after doing a small drive around the neighborhood. However, when I got on Techstream, I found that my front pressure was a 9.2. My readings were in spec prior to the globe change, so I found this interesting. I cycled from L to H several times to see if that would relieve any pressure, but it was holding steady. I needed to borrow the proper socket wrench from a friend to adjust my torsion bars, so I had to drive to his house. On the drive, I did notice the ride was noticeably rougher when I got her up to 60mph. While at my friends, I cycled from L to H again and we did hear some gurgling coming from the AHC reservoir. Now my ride home was much smoother at 60mph than on the way there. I Techstreamed back at my house and my front pressure had dropped to 7.1. From there, I just followed the YotaMD instructions (thank you, sir) on adjusting the pressures via torsion bar cranking and I'm now within spec again. So for anyone that runs in to some pressure issues after installing new globes, it appears that you can work some of the pressure out by driving and cycling through L to H several times. I'm going to continue to monitor the levels to see if it continues to lower with time and use. All in all, I'm happy to have got this done, however, I'm not sure how much difference I can say it's made in the ride. All my old globes passed the pencil test, which I have seen mentioned before, so I guess I'll hold my final judgement until I get a few more miles on the new globes. Thanks again to everyone on the thread for the information posted.
I have not changed my globes yet. I’m waiting for Impex to ship them out. However, I had the same issue after doing a bleed to get air bubbles. Truck was stuck in low and Off was blinking. The ahc reservoir seemed to be clogged because the fluid inside wasn’t moving. I found the following thread and replaced the pump sub-assembly, and everything is back to normal. Maybe cleaning out the sludge will work but I had a pump sub-assembly laying around so I just replaced it.
3 flushes must have loosened all this gunk up and it accumulated in this pump area. I used a used pump sub-assembly from someone ditching their ahc. Maybe cleaning will work too.
I have a feeling this is your issue. I was surprised at how much gunk there was.
Hope this helps.
Finally fixed my AHC! Changed pump~ - https://forum.ih8mud.com/threads/finally-fixed-my-ahc-changed-pump.287320/
Thanks for the info! I have an appointment scheduled with the local 4x4 shop on the 22nd. If I had more time and patience I'd probably order a new sub assembly but at least now I'm aware of the cost of a new one from Impex (Looks like about $150 shipped). Hopefully I get a fair quote on parts and labor otherwise I may be doing this myself. I may spend some time this weekend tinkering around with the system and see if I can clean out the pump without making too much of a mess. That AHC fluid doesn't wash out of clothing very well.
@Dref: An interesting discovery! Given that you have removed the suspect AHC Pump sub-assembly and if you have the time and inclination, it would be interesting to know (with pictures) what the internal condition was like inside the Pump sub-assembly. Dis-assembly is straightforward. Here are some links with a few more pics and explanations:
Post #67 by @BullElk at AHC pump out? - https://forum.ih8mud.com/threads/ahc-pump-out.1226629/page-4#post-13401098 for pictures of a clogged pump.
Posts #69 and #70 by @IndroCruise at AHC pump out? - https://forum.ih8mud.com/threads/ahc-pump-out.1226629/page-4#post-13407297 and onwards shows pictures of AHC Pump disassembly and also show the tiny filters (strainers) within the Pump. Pump disassembly and cleanup of the pump by easing out the pressed-in filters (strainers) with a pick and/or backwashing are all straightforward -- made easy when the motor/pump/tank assembly already is removed from the vehicle. Even if the decision is to replace the pump, disassembly of the existing pump is still recommended. It is better to know how much jelly-like 'gloop' is in the system (caused by very old fluid), particularly at the tiny internal strainers, when installing a new pump and risking another blockage. The FSM diagrams also suggest that there is a similar strainer in the Return Valve after the Pump, before the pipe leading to the Control Valve Assembly. The Return Valve is within the milled metal block to which the Pump and Motor are attached on either side.
The next link shows a picture of the tiny orifice sizes in the Damping Force Control Actuators (to which the 'globes' are attached).
AHC with harsh ride - https://forum.ih8mud.com/threads/ahc-with-harsh-ride.785364/page-4#post-9843856
The point of all these pics is to illustrate what degradation is possible and to provide an incentive to keep regular AHC Fluid changes more than up to date, maybe twice as often as the schedule in the Owner's Manual.
Cleaning up the AHC Pump is never a bad idea. However, not sure that @Moderator should jump too quickly to conclusions that this will fix everything -- suspect that there may be additional problems in his case, to be covered in a separate post.
I’ve been trying to not throw parts at the AHC system although I bit the bullet and bought the Impex globes because the price is the best I’ve seen. And I suspect 21 year old globes are contributing to a less than ideal ride. For now, NP are in spec, new (to me) height sensors are installed, flushed the system 3 times (never been flushed in 150k miles), king springs in the rear.
I was pissed when after my 3rd flush, the LX was stuck in Low and Off blinking. Thanks to the knowledgeable members of this site, I was led to inspecting the pump sub-assembly and replacing it, although a cleaning of the area may work. @IndroCruise is way more knowledgeable and detailed and I am going to review some info he posted about the part. It’s really not that hard to get to if I had to do it again to clean the part more thoroughly. @IndroCruise had some pics of three tiny filters I may want to inspect.
Just drain AHC fluid from the reservoir and there is a bolt between the reservoir and the firewall that is a bit difficult but manageable.
@IndroCruise Thanks for the more detailed analysis of the pump! I’m sure I encountered your info in other threads as well.
I did not clean out those 3 little filters you have pictured. I may have seen your post on them before but so much info, I get lost sometimes! I’m so concerned with fixing er up I don’t take pics that I should have!
I noticed that the part I installed was different from the original. The original easily came apart and I saw the cogs in the assembly. The one I installed did not pull apart easily at all. I thought I read somewhere that the part may have been improved to address past issues with the assembly so I thought that may be the reason for the difference.
When I have time I will attempt to disassemble the old pump more thoroughly. For now, I’m happy the height control is working again. Can’t wait for these new globes.
I got new tires today and on the way home the car started to bounce like it did before I replaced the globes. Not sure if jacking up the car to put the tires on had anything to do with it. When I got home I disconnected the battery to see what that would do. That did seem to reset something because when I started the car I was able to raise the vehicle but only the front raised. Got some friends in town this weekend so not sure how much tinkering I'll be able to do. Starting to worry about my repair bill once I take it to the shop on Thursday but at least now I know how much all the parts cost if ordered from Impex.
Got a call from the 4x4 shop and I'm assuming they don't have the right kind of software to talk to the system because they advised I send it to Toyota or Lexus dealership. That sucks because I know Lexus isn't going to let me out of their shop without spending a few grand. Anyone near Fort Collins that can fix this rig? If the 4x4 shop in town (that has a land cruiser loaner) can't fix it I know I can't.
Late edit: Pics attached at end of post.
I feel your pain!!
Great descriptions in your posts. If I have understood correctly, the observed symptoms are summarised below. Of these, the most troubling is Item 10 in the list below – because it means that power is not going where needed for operation of the AHC/TEMS system.
1. All four ‘globes’ have been replaced recently,
2. AHC “Off” light blinks,
3. AHC does not respond to AHC “On/Off” switch on centre console,
4. AHC does not respond to “Up/Down” rocker switch on centre console – does not raise or lower,
5. AHC system has been bled multiple times (??). [Notes: Description at Posts at #324 and #339 says: “…. turning on the vehicle to let it adjust height, then bled all the valves to get the air bubbles out”. This may not be enough – better to drop to “LO” them bleed – but it seems that the vehicle will not raise or lower? If it has not been possible to use a method such as the @PADDO method -- https://forum.ih8mud.com/threads/replacing-ahc-globes-accumulators.716383/#post-11432901 -- then there is a very high risk of air still in the system, especially after a ‘globe’ change. There are quite a few Posts on IH8MUD where Members have struggled to get rid of remnant ‘plugs’ of air in the system – frustrations eventually solved by repeating the recommended method – but necessary to raise and lower multiple times],
6. Techstream was not used, not available to Owner, Fort Collins 4x4 recommends “go a to a Dealer” [Notes: More frustrations and again I feel your pain -- can a Dealer or other workshop be found with Technicians willing and able to interpret physical symptoms and Techstream readout, not just plug in the scanner?!],
7. On start-up, vehicle does auto-level as expected. This may mean that AHC Pump and the Height Control Accumulator (long cylinder on LHS chassis rail) actually is working? [Notes: Need to check by listening/feeling at Pump and Accumulator pipes when vehicle is auto-levelling],
8. Fuses checked? [Notes: Which fuses? Have all AHC fuses and relays been located?]
9. Attempted re-set – disconnected/reconnected battery – then found Front raises but not the Rear. [Notes: If not already done, also suggest further re-set attempt by pulling AHC IG fuse behind LH cover on LH footwell, inspecting, resting, replace for certainty -- then re-inserting fuse – see pic below]
10. AHC Height Control Operation Test (a.k.a. “Active Test”) does not work per posts #327 and #334 in this thread.
Notes: This is very unusual.
In this test, be sure engine is running, not just ignition “ON”.
If “Active Test” does not work, it means either
(i) something simple – like faulty console switches. Suggest check/clean console switches per Suspension problem even after replacing almost everything - https://forum.ih8mud.com/threads/suspension-problem-even-after-replacing-almost-everything.812905/page-2#post-9444024, then suggest follow the whole “Pre-Check” procedure set out in the attachment to my Post #327 in the current thread. This does not require Techstream,
OR,
(ii) pump is blocked (can happen) or motor is faulty (unusual) or power is not arriving at the AHC Pump. Suggest check operation of AHC Pump and Motor: pull plug from the Motor, apply power to Motor using leads from 12 volt battery directly to the motor terminals. This does not require Techstream,
OR,
(iii) if pump operates by direct connection to battery but not in ordinary operation nor in “Active Test”, it means power is not getting to the Pump and the AHC system. By inspection and with a multimeter (Techstream is not required):
- check AHC- B Fuse and AHC IG Fuse in Left Hand Side kickpanel in the driver’s footwell, and,
- using FSM instructions, test the AHC Main Relay located at or near the Electronic Control Unit (ECU) under the dashboard on the upper Right Hand Side of the driver’s footwell.
Quick question about AHC ride with extra weight - https://forum.ih8mud.com/threads/quick-question-about-ahc-ride-with-extra-weight.1247828/page-3#post-13957466
including Posts #71 and #76 in that thread for pictures of possible different fuse panel layouts.
With the above observations in mind, may I also suggest that it is worth going back yet again to the FSM "Diagnostics" section:
https://lc100e.github.io/manual/
At this link, use the Index on the left hand side of the opening page and follow these tabs:
Repair Manual > DIAGNOSTICS > ACTIVE HEIGHT CONTROL & SKYHOOK TEMS
Before getting into all the detail, the FSM outlines at the start this section a diagnostic process. Among other things, this explains situations in which Diagnostic Trouble Codes (DTC's) may not be recorded even when faults or 'difficulties' exist.
The upshot is that Techstream is an extremely helpful tool, no doubt about that, and the presence of a DTC may help to identify and fix a problem (and usually does).
However, the reverse is not true – the absence of DTC’s does not guarantee that all is well.
The point is that investigation by observing symptoms and by being handy with a multimeter, considerable progress can be made.
At the above FSM reference, “Terminals of ECU” (FSM Page DI-248) provides a way of doing ‘health checks’ at the terminals of the ECU.
The diagnostic adventures of @YvesNL can be seen at the next link and may provide some insights:
Hi From The Netherlands & AHC Issues - https://forum.ih8mud.com/threads/hi-from-the-netherlands-ahc-issues.997849/page-3
Hope that somewhere in all this information, there might be a helpful starting point!
Two variants of LHS Footwell Electrical Panels:
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I just did our first AHC Evaluation service at our Air Down Gear Up shop in Frederick/Erie, CO today. I'd be happy to take a look. We charge a minimal evaluation fee and then typical specialist labor rates if we find something we can act on.
Shoot me a PM or email if you like. I'll be in the shop tomorrow and then some of next week.
info@airdowngearup.com
Wow! Thanks for all the detailed info! This forum and all the folks that contribute to problem solving issues is the reason I bought a 100 series. Much appreciated.
If I can't get it fixed this weekend I'll shoot you a pm next week. I get off shortly after lunch sometimes on Fridays so might be heading that way next week.
Another successful purchase from Impex; they arrived last week at 561.57 for the globes and 97.36 for shipping, 658.93 all in. I also ran across this 36mm wrench that is of outstanding quality. It was a perfect fit and zero flex. Amazon product ASIN B001ILECSQ
shtbrwn86
SILVER Star
That is such a good price! I’m about to order them even though they were definitely not in the budget lol
how long did the whole process take you?
For me from date of order to completing the project about 19 days
My order was 13 days start to delivered. Just under 700 including shipping. It wasn't in my budget either but I felt like I was taking a risk considering my originals had 347k on em.
shtbrwn86
SILVER Star
347k? Woah. I’m at 251 and mine are definitely shot. I love the system though and want to keep her going! Thanks for all the information everyone!
146K 2005 LX just changed globes, Impex $680 (thanks for info and experience)
Not a lot of change to the ride, not much change from comfy to sport, but have bleed twice
Improved gradations from 9 to over 16
What is funny is the accumulator and 2 rear globes bleed clear, but 2 front globes first bleed clear right out of the nipple and then within
2/3 seconds many very small bubbles form out of the clear fluid, then drain into the bottle foamy, after 5 minutes foam is clear
It's like the gas (nitrogen, maybe air?) comes out of the fluid at atmospheric pressure
Nothing like bleeding brakes with large 1 -3 mm sized bubbles
Anybody else seen this? know what might be going on
Thanks
Not a lot of change to the ride, not much change from comfy to sport, but have bleed twice
Improved gradations from 9 to over 16
What is funny is the accumulator and 2 rear globes bleed clear, but 2 front globes first bleed clear right out of the nipple and then within
2/3 seconds many very small bubbles form out of the clear fluid, then drain into the bottle foamy, after 5 minutes foam is clear
It's like the gas (nitrogen, maybe air?) comes out of the fluid at atmospheric pressure
Nothing like bleeding brakes with large 1 -3 mm sized bubbles
Anybody else seen this? know what might be going on
Thanks
Yes, my last globe change I had this with nearly fresh fluid from a previous ahc flush before replacing the globes. If you are still getting air, I would completely depressurize the system and do another flush
