pair of AHC globe questions (1 Viewer)

[ylexot]

So my AHC globes appeared to be toast: 6 ticks on the reservoir between H/L and crumby ride. I got a set of used globes that were in good working order when removed. I've got a couple questions:

1. Is there any way to tell if one globe is OK on or off the rig?
1.5. I noticed when bleeding the pressure off the Passenger side globes that there were no bubbles in the line the fluid, where as the driver's side was frothy like Cujo's mouth. Is this an indicator that the DS side was toast, but maybe the PS is OK?

2. When trying to remove the used globes from their actuator with a strap wrench, I heard a sound like gas escaping, like the sound of popping a beer open or opening a can of tennis balls. I can't be certain where the sound came from. I haven't heard the sound in the garage before, but it could have been the hot water heater or furnace which are close to my work bench. My concern of course is that I broke one of these globes. Thoughts?

 

[CreeperSleeper]

This is all I got... http://www.metaltech4x4.com/p-472-ironman-4x4-100-series-land-cruiser-suspension-2-lift-kit.aspx

 

[ylexot]

Haha... I'm not giving up that easy Chad.

 

[ylexot]

Well, it seems I answered question 1.5 and 3 for myself.

I installed the younger globes on 3 corners, bled the system, took it for a test ride, and looked at the fluid heights between H and L. The ride with 3 of 4 globes swapped out was about 40% better. There was more of an ahc feel to it rather than the bouncing juttery ride I've tolerated with clinched teeth. Definitely riding on more of a cushion. The reservoir confirmed an improvement going from 6 ticks to 8.

After I got my boys off to bed I figured I'd go ahead and swap in the last, possibly broken globe onto the passenger front actuator. Removing the old unit, I noticed that it contained a lot more fluid than the others. I screwed on the possibly broken unit, and cued up the system for another test run. Suddenly the reservoir is showing 12 hashes difference between H and L. The test drive was so much more pleasant than the last.

It seems I did not break the globe and the hissing sound must have been from another source.

Froth vs no froth is still a mystery, but the absence of froth may either indicate a bad globe or nothing at all.

I'm surprised at how much difference the one globe made.

 

[uHu]

Good work. Thanks for sharing. 12 ticks is like nearly new then. So, your globes lasted 15 years? How many miles?

 

[ylexot]

The original globes lasted about 149k. I bought this LX with 145 on the clock and was emotionally, but not financially, prepared to repair on the system. The used globes I just installed have 110k. They should last me a several years if they go another 40k+.

 

[TXLX100]

Where did you source used globes from? I'm debating repairing my system. I still like it and it's perfect for the amount I go offroad.

 

[Kigiin]

I have never checked mine until reading this thread. I had at least 12 ticks. I would have thought after almost 200k miles the effectiveness would have been greatly diminished. Especially with the bumpers, winch, rack, aux gas tank, and drawers. With that said, I don't think the ride is all that great these days. Maybe I just need to change the fluid.

 

[ylexot]

Where did you source used globes from? I'm debating repairing my system. I still like it and it's perfect for the amount I go offroad.

I picked up my used globes from a fellow 'Mudder who went OME. Keep your eye on the classifieds here. I got all the hydraulics and sensors from his kit for less than cost of 1 globe direct from Toyota.

I have never checked mine until reading this thread. I had at least 12 ticks. I would have thought after almost 200k miles the effectiveness would have been greatly diminished. Especially with the bumpers, winch, rack, aux gas tank, and drawers. With that said, I don't think the ride is all that great these days. Maybe I just need to change the fluid.

200k is pretty good. I've seen posts with guys stretching into the high 200s with original AHC components. I've also seen some guys on their second set of replacement globes in less than 100k. I'm imagine the variability has something to do with the driver and use as Toyota QC is usually pretty good.

I'm about to start adding armor and such. I've got 180lb of bumper/winch going on the front in the next week or so. How long have you been running with all the extra weight in armor? Have you checked your N pressures? Original springs/torsion bar tension?

Flushing fluid is a good idea. I think the AHC fluid is only rated for 50k. It improves the ride for those with good accumulators. Bushings are also noted to improve ride and handling. I just read about those yesterday, so that's next on my research list.

 

[TXLX100]

Thanks. I'll try that or the amayama. Com. I think fluid maintenance is most important to longevity. Mine 100 was an older couples' vehicle, so it wasn't abused but the fluid wasn't changed every 30k. I have 140k now and the globes are really stiff.

 

[ylexot]

I tried amayama first. They have the best price for sure, but now can't ship these until they get a Toyota MSDS for the accumulators complete with part numbers referenced on the sheet. I have another thread on here looking for these sheets, but no luck so far.

 

[PADDO]

The best non intrusive way to test damper performance and identify a completely failed (burst diaphragm) globe accumulator is to do the damper actuator test: simply short Ts and E1 in DLC1 and start the vehicle. You will have Christmas tree flashing light on the dash because AHC is in diagnostic mode and you have forced the system to select step1 damping which is the softest setting. Walk around and push down on each corner and feel the response. Pushing the brake pedal steps the damping system to step 2, check each corner. Keep pushing the brake and monitoring all the way to step 16 which will be rock hard. This test does two things: verifies that each damper actuator is responding and identifies which corner or corner's globe accumulators are weakest or failed. All accumulators will gradually loose their charge through permeation, industry standards are between 5 and 10% per year so at 10% per year our 2.2MPa globe accumulators will be at about 50% charge in 6 years. Foam in the system almost guarantees a burst accumulator. The final test to confirm a burst diaphragm is to actually remove the accumulator, if it's full of fluid you've lost your charge and it's well and truly done. But before you break open the system force it into soft test mode, if you have three ok soft corners and one that's harder you've narrowed down the problem. You don't need techstream to do this test but if you have it you can hook it up and watch the front and rear step positions change from 1 through 16.

 

[ylexot]

Awesome! That sounds like a fun and informative test. I was hoping you'd show up and shed some light in the darkness.

So bottom line, due to expected leakage of N2 through the diaphragm means that the globes should be approaching useless after ~10 years, from that one factor alone. Or perhaps a better question, how much pressure has to remain in the globe for reasonable functionality? The globes are about down to 0.7MPa after 10 years just from expected leakage. I imagine the leakage slows as pressure drops, but the diaphragm has to stretch more because there isn't pressure holding it in place.

 

[PADDO]

Awesome! That sounds like a fun and informative test. I was hoping you'd show up and shed some light in the darkness.

So bottom line, due to expected leakage of N2 through the diaphragm means that the globes should be approaching useless after ~10 years, from that one factor alone. Or perhaps a better question, how much pressure has to remain in the globe for reasonable functionality? The globes are about down to 0.7MPa after 10 years just from expected leakage. I imagine the leakage slows as pressure drops, but the diaphragm has to stretch more because there isn't pressure holding it in place.

Yes, natural permeation will eventually render the globe useless, I'd guess that if new globes just sat on a shelf they'd probably have a life of maybe 20 to 25 years. We all know Toyota had world leading standards when these systems were designed so I'd be very confident that they would have specified leakage rates below 10% and probably even below 5%. I come from a military engineering/fluid power/industrial control systems background and 10% would not be acceptable and spare accumulator diaphragms and bladders (we could/did rebuild blown accumulators regularly) had a shelf life of maybe 10 years before they were thrown out. How much pressure do you need for reasonable functionality? Excellent Q, I'd love to have access to a hydraulic test bench and a dozen new and used accumulators and we could come up with a reasonable answer. As a general design rule I'd speculate that at a point below 50% charge you'd have difficulty maintaining satisfactory performance, just a WAG. And definitely, as nitrogen pressure diminishes over time the diaphragm will experience greater deflection, stressing it towards mechanical failure. It would be very nice if these globes had a charging fitting!

 

[TXLX100]

Blank

Posted to wrong thread.

 

[ylexot]

A recharge fitting would be awesome. I expect extra losses through the fitting, but who cares plug into a cylinder of N2 every 2-4 years and be happy.

I'd love to squeeze a few more years out of these used units. I'll try the test you outlined this weekend and see how they're doing. I'd still like to get some new accumulators or at least have some ready in the wings, at a price what amayama offers.

 

[PabloCruise]

Yes, natural permeation will eventually render the globe useless, I'd guess that if new globes just sat on a shelf they'd probably have a life of maybe 20 to 25 years. We all know Toyota had world leading standards when these systems were designed so I'd be very confident that they would have specified leakage rates below 10% and probably even below 5%. I come from a military engineering/fluid power/industrial control systems background and 10% would not be acceptable and spare accumulator diaphragms and bladders (we could/did rebuild blown accumulators regularly) had a shelf life of maybe 10 years before they were thrown out. How much pressure do you need for reasonable functionality? Excellent Q, I'd love to have access to a hydraulic test bench and a dozen new and used accumulators and we could come up with a reasonable answer. As a general design rule I'd speculate that at a point below 50% charge you'd have difficulty maintaining satisfactory performance, just a WAG. And definitely, as nitrogen pressure diminishes over time the diaphragm will experience greater deflection, stressing it towards mechanical failure. It would be very nice if these globes had a charging fitting!

The ability to recharge these would be awesome!

 

[PADDO]

The ability to recharge these would be awesome!

There's a gent in England by the name of Martin who has the capacity to recharge OE spheres

 

[Jimmy808]

Aloha All
I live on Kauai Island and would greatly appreciate any suspension information for my 2006 Lexus LX 470. I bought it used from a Lexus dealer in California in 2012. It was shipped to the big Island first where I drove it for a couple years fairly good roads. Then here to Kauai. I learned later that securing, and tie down for transport may cause damage to the suspension system. The vehicle has 51,500 miles looks like nearly new. My vehicle is hard riding, stiff over bumps, uneven pavement, and potholes, etc. The roads here are really bad for me as I have a spinal injury that causes a lot of pain, while riding in my vehicle. After reading some posts; should I start with testing the numbers of marks on the AHC fluid reservoir between high and low setting? If I need a really smooth ride, how many markings would be optimal? I plan to get a techstream to use for preferences for locking and opening windows. It seems it would be helpful for testing the globes. I hoping that they don't need replacing. I also noticed posting regarding bleeding the accumulators / globes maybe that would get my smooth ride back? Does my order in testing suspension look right and is there some things I missed? There is only a Toyota dealer here. I had them look at my vehicle and they said it was fine??? At least they didn't charge me, nice people. Thanks in advance Jim.

 

[ylexot]

Im still looking for a solution to the rough ride. My suspension is nominal by all metrics, yet still harsher than it is supposed to be. New globes, new tires, most bushings, still harsher ride than my wifes RX. Ironically, the lX handles better: curves, turns, big undulations are dreamy in the LX. Little bumps come right through.

I keep coming back to being over sprung, but my pressures are right on per Techstream. I'd like to get true pressure readings from the hydraulics. That's my next diagnosic step, i think.