AHC accumulator replacement from McMaster?

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you may freely use anything I post on a public forum. Please just give attribute to us. We ARE trying very hard to provide a superior product and excellent customer support for these vehicles. Our profit margins are not excessive (unfortunately) because U.S. laws and regulations are complex and costly. (We just spent over $ 1500just for the annual renewing of the various business licenses and registrations required so far in th U.S. Small Business is getting inundated with more regulations this year and each is going to be costly. 'Overhead' expenses such a licenses, registrations, mandated policies, insurance, health insurances, employment taxes are choking. Just legally mandated employee benefits , including minimum legal health coverage, adds right at 100% to wage costs now. We could not find a single U.S. Company to make the accumulator shells. We now have them forged at a 'N stamp' (nuclear qualified) shop overseas. Cheaper shops made junk too often and inspection costs went crazy. We still have to test 3 samples from each 1000 shell batch to confirm burst pressure and 3 more to confirm that when at maximum charge pressure and immersed in a DOT/FAA 'standard fire' they fail without generating dangerous shrapnel--and those tests videoed and reports notarized. That's costly, but keeps us legal.

Glad you are taking the lead on this subject.
 
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So, after spending way to much time reading about the hydropneumatic accumulators(mud has made me paranoid) I can't see how fining a replacement accumulator would be a major headache. Finding a correct size hydropneumatic accumulator is a moot point. It will not be the size that is the issue, it will be the internal pressure on the nitrogen side. If they nitrogen side is the correct pressure, and the accumulator is larger, then you could simply add more of the ahc fluid to fill the void, and bring the fluid side back to the correct pressure. I wouldn't think going smaller is a good idea as it would simply increase the load and the heat buildup. From what I have read our mounting option is not completely standard, but it is a lot less costly to have an adapter created than it would be to create an entirely new accumulator. The only problem I can see arising is where the ahc fluid pressure is mounted. I am assuming it would have to be between the shock and the accumulator, as what happens on the height control side is irrelevant to the dampening of the system. Maybe I have been up to long and am totally off.
 
I took a look under the truck when I did my AHC flush. The globes fit at an angle relative to the frame, which contrains its external dimensions.

I assume these aftermarket replacements are just longer and more cylinder shaped rather than globe shaped? I understand the adapter would be to adapt to the right thread size. But is it also true that it is to angle and locate the globe such that it's parallel to the rail?

If that second part is true, it might be just as easy to reposition the AHC valve system that connects to the globe. Just need to tweak a few metal lines?
 
Accumjulator alternatives what are they?

We at B and B Suspension LLC continually peruse the 'world of accumulators' seeking to further improve our product. The LC/100 and LX-470/570 AHC suspension has unique requirements for the hydraulic accumulators for the struts.

Neither the front or rear accumulators are a standard size--we carefully measured the actual internal volume, with and without the internal components. Our products match the OEM parts so the 'spring rate' is maintained and full suspension travel is maintained.

The 'screw-in' mount-connect configuration is also non-standard and severely limits options for alternatives. ANYTHING is 'possible' --such as remotely mounting the accumulators and connecting them with high pressure flex lines and adapter fittings---but that additional complexity turns a very simple and fast swap-out into a lengthy and costly 'custom mount and connection' package' and installation procedure.

We do not and did not find ANY commercially available accumulator to be suitable for use 'as-is' due to mounting configuration. space limits, and connection method. Neither is it feasible to modify the 'stock' accumulator connecting methods to that required by the Toyota design.

Another critical issue is the diaphragm material--ensuring a very long life with suitable hydraulic oils. The material we use in our custom manufactured diaphragms is the best available for GENUINE Toyota AHC oil (and other suitable petroleum based hydraulic oils which we have tested.)

We caution all readers of this to note there apparently is some counterfeit or defective 'AHC oil' in Toyota's supply system and being sold as the Genuine product. However the 'bad stuff' IS NOT COMPATIBLE with either OEM nor B&B accumulator diaphragms and will cause their failure in days to weeks (or months) depending on how much of the bad stuff is in the system. We suggest testing EACH container by our simple Water Reaction Test---which is a very quick and easy 'field use version' of Toyota's [industry standard] specification
 
Accumulator alternatives what are they?

We at B and B Suspension LLC continually peruse the 'world of accumulators' seeking to further improve our product. The LC/100 and LX-470/570 AHC suspension has unique requirements for the hydraulic accumulators for the struts.

Neither the front or rear accumulators are a standard size--we carefully measured the actual internal volume, with and without the internal components. Our products match the OEM parts so the 'spring rate' is maintained and full suspension travel is maintained.

The 'screw-in' mount-connect configuration is also non-standard and severely limits options for alternatives. ANYTHING is 'possible' --such as remotely mounting the accumulators and connecting them with high pressure flex lines and adapter fittings---but that additional complexity turns a very simple and fast swap-out into a lengthy and costly 'custom mount and connection' package' and installation procedure.

We do not and did not find ANY commercially available accumulator to be suitable for use 'as-is' due to mounting configuration. space limits, and connection method. Neither is it feasible to modify the 'stock' accumulator connecting methods to that required by the Toyota design.

Another critical issue is the diaphragm material--ensuring a very long life with suitable hydraulic oils. The material we use in our custom manufactured diaphragms is the best available for GENUINE Toyota AHC oil (and other suitable petroleum based hydraulic oils which we have tested.)

We caution all readers of this to note there apparently is some counterfeit or defective 'AHC oil' in Toyota's supply system and being sold as the Genuine product. However the 'bad stuff' IS NOT COMPATIBLE with either OEM nor B&B accumulator diaphragms and will cause their failure in days to weeks (or months) depending on how much of the bad stuff is in the system. We suggest testing EACH container by our simple Water Reaction Test---which is a very quick and easy 'field use version' of Toyota's [industry standard] specification
 
eleblanc said:
I have a friend who is a hydraulic specialist, he works for a large company that design and built all sorts of hydraulics system and they sell and everything about hydraulics.

I called him and sure enough he knows about nitrogen accumulators, he says it is not a big deal to put it back to spec pressure. They have all the necessary to do this, he says they have full time people doing this all day long to rebuilt accumulators, mostly for large truck. He told me to bring them in and he will put them back to pressure and it will be real cheap. But he confirmed that if the diaphram is ruptured or leaking i'll need a new one. He told me he is sure he can find one that will fit. I'm not too sure about that, toyota probably designed the accumulator for specific volume and pressure. Anyhow i told him roughly the size and at worse a new one is 250$. Again if it fits under the truck...

Now last week i found a scrap yard with a LX470, If my friend confirms he can refill them i will buy the 4 accumulators (if price is fair) and get them recharged and swap them on my truck and see if all works out.

I'm pretty sure B&B pricing is right under the cost of new ones at the dealer, he must be doing lots of $$ at 375$ a pop + old cores. i'll keep you all posted.

uHu are you sure about the volume and pressure?
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I realize this is a pretty old bump - wondering if this worked?
 
Why can't you use a floating piston in a cylinder like a remote res shock instead of a globe? That would be serviceable unless the O Ring on the piston is a possible failure point compared to the frictionless diaphragm.
 
MILOWILLI said:
Why can't you use a floating piston in a cylinder like a remote res shock instead of a globe? That would be serviceable unless the O Ring on the piston is a possible failure point compared to the frictionless diaphragm.
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Funny, we recently purchased an LX470 and the first thought I had was to put a piston style remote reservoir off a King, ADS or similar off road shock in place of the accumulator. I've had a reservoir open on a King shock and they are remarkably simple. The only issue I see is the much higher pressures of the accumulators on the Toyota system. I don't know if the reservoirs are close to capable of the 400 psi or close to it. I also can imagine that they would be better than flat and or dead OEM accumulators at the 200 psi the reservoirs are capable of... Would be neat to see someone try. One could easily get/make an adapter from the 1/2" NPT hose on a off road shock reservoir to the 22x1.5 which would make it easy to mount.

Edit: I also understand that the accumulator does more in the AHC system where in the offroad shock the reservoir only keeps air bubbles out of the oil... It still seems that one could machine a piston, cylinder and components (basically an offroad reservoir) but the appropriate diameter/size to interact the same way as the globe. Yet completely serviceable and adjustable.
 
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Has anyone taken apart an actuator? Is the motor in it self contained? I'd like to take mine apart and soak them in solvent and do an ultrasonic cleaner.
 
You mean the actuators that the globes are attached to? Don't know how, but it sounds like a good idea to service it.

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uHu said:
You mean the actuators that the globes are attached to? Don't know how, but it sounds like a good idea to service it.

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I agree! I am about at my wits end with my AHC. I have studied it for months. I have reviewed my pressures, I have replaced my globes. Flushed the system twice. And it still rides just awful!! I’m wondering if I can take apart the actuators and clean them in a sonic pulse cleaner.

I bought this completely stock with 250,000 miles on it and the fluid was disgusting the first and the second time including settlement of debris in the fluid as well. So I am wondering if the fluid has never been changed and there’s moisture like a break fluid and possible corrosive sentiment getting clogged in the actuators and not allowing the screw to back out all the way giving me a hard ride. I talked to Lexus’ top AHC mechanic here in Atlanta and they said I know more about the system than they do. Mine is a 2006 LC
 
yey, that MUV70-500-30 looks right. Ask them to charge it with 2.26 MPa for the fronts and 2.65 MPa for rears. Is it the right threads - G3/4 ?

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I remember reading the rear globes will fit in the front, is there any benefit to charging the front the same as the rear?
 
uHu said:
yey, that MUV70-500-30 looks right. Ask them to charge it with 2.26 MPa for the fronts and 2.65 MPa for rears. Is it the right threads - G3/4 ?

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So...full disclosure....I am in the process of buying a LC. I haven't actually gotten it yet, but am fairly certain based on the Toyota Maintenance history that I pulled using the VIN that the AHC is in need of some TLC. The technician notes were a bit screwy because it said KDDS system parts were quoted but the KDDS didn't appear until after the 100 series, but I attributed this to a tech that simply got the acronym wrong.

When I get the LC (within a week), and if I determine the AHC needs to be addressed, I will likely reach out and see what it costs to get them charged to those pressures. Otherwise, I will order the Citroen globes from the English shop. The issue here is whether they need bulk orders. If these things are much cheaper, this may be worth looking into.

I also have access to some functioning globes that were removed off a LX-470 that was converted over to shocks. I am told the English shop Pleiades can restore globes that still have good diaphragms.

I'm a newbie...but learning....
 
uHu said:
yey, that MUV70-500-30 looks right. Ask them to charge it with 2.26 MPa for the fronts and 2.65 MPa for rears. Is it the right threads - G3/4 ?

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@uHu

Do you recall the size of the globes? I think on the landcruiserclub, someone posted pictures of the globes along with a caliper showing the thread size and overall diameter/height of the globe. I thought i had saved those pictures the other day but apparently didn't hit save and now cannot find them.

I am trying to determine which globe to "order" if I need them. I assume i would simply request a MUV200-500-30. What temperature should I specify?

Also - Thread type?

Any help would be appreciated.
 
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