AHC accumulator replacement from McMaster? (1 Viewer)

[Yotato]

I think we're getting somewhere with this. Here's my guess on the replacement model: HAD,07-350-2X/200Z08C-4N12-BA

Wanna give it a try.

Here is the manual.

I'm sure B&B orders through here. Can someone here find the time to call the mfg on the pdf to ask for their recommendation on a replacement model. An engineer should be able to figure this out with the above manual.

 

[SerasLibre]

Agaisin - You are correct, the suspension travel is the same over the same bump regardless of ride height, but the allowable travel is larger on our trucks, so the spheres must be bigger (I assume) than those found on passenger cars.

Parnoren - I really like the idea of converting over citroen globes. They appear to be the most reliable, and most of them are rebuildable. It appears that spheres used in older vehicles were mostly rebuildable (and longer-lasting), whereas modern vehicles use sealed units that have a shorter life. I found that these spheres used on Mercedes 300TD wagons have a lifetime of about 10-12 years, which is much better than what we are seeing with ours.

uHu - thanks a lot for the photos. They've helped clear things up a bit in terms of dimensions.

I noticed that we can spec out a Rexroth unit from the link posted by Yotato, but having dealt with them before this is not a cost-effective option. They did, however, clarify the two things that will extend the life of the sphere;
1. Minimize the amount of motion in the bladder. There are two ways to do this - A. By getting a bigger sphere, or B. By using two spheres in parallel.
2. Minimize the pressure difference on the nitrogen filled side as compared to the hydraulic side. Either A or B from above will accomplish this as well.

By the way, Wikipedia has an excellent article on the benefits (and disadvantages) of keeping this type of system operational. The rest of the world calls this system a "hydropneumatic suspension".
Hydropneumatic suspension - Wikipedia, the free encyclopedia@@AMEPARAM@@/wiki/File:Merge-arrows.svg" class="image"><img alt="Merge-arrows.svg" src="http://upload.wikimedia.org/wikipedia/commons/thumb/5/52/Merge-arrows.svg/50px-Merge-arrows.svg.png"@@AMEPARAM@@commons/thumb/5/52/Merge-arrows.svg/50px-Merge-arrows.svg.png



At this point I see two cost-effective alternatives;
1. Use mercedes spheres; They are made to be remote-mounted units. There is very good documentation on them here. Cost is $133 on ebay. We would have to run plumbing from the actuator valve to wherever is best to mount the spheres.

2, Use citroen spheres; They are the inventors of this technology and use rebuildable spheres - although new spheres are cheap enough to not bother rebuilding them. Cost is about $40 on ebay. They have a much larger port than what we use, so some adaptation would be necessary.

 

[SerasLibre]

I've been doing a LOT of research through landcruiser forums from the UK, spain, Africa, and Australia, and think I may have found a good lead.

A UK forum posted some very promising information on a Citroen hydraulic suspension specialist company in the UK that can rebuild spheres that have yet to fail, or sells citroen retrofit spheres modified to work on the LC100 series.

I have e-mailed the company and hope to hear back from them soon.

 

[agaisin]

SerasLibre - thanks for doing legwork on this! Is this the post you are referencing?: Spheres - 100 Series &bull; Land Cruiser Club and Forum
an excerpt from nathanrobo's post:
"Prices seem to be:
£45 for a sphere recharge and appx. £100 for a sphere recharge.

At the moment the service is parts only, but when they become more familiar with LC's and can price the work effectively they will offer a fitting service too! From memory their real selling point was a 2 or 3yr warranty on recharged spheres where the new warranty on new parts from the dealer was 1 year.
"

And that post was from end of Aug 2010. If the parts were reasonable enough in cost this could be an amazing find! However the site references I found for pleiades in uk were both dead:
pleiades.co.uk and http://www.Citroën-hydraulics.com/
Did you find any other contact info for them? Can't wait to hear what you find out.

 

[SerasLibre]

Ok - I just spoke with someone at Pleiades and we have some exciting news partly confirming my earlier post.

Good news;
They recharge our spheres for 35 british pounds each. Thats $220 for four spheres!
There is a catch, however - the spheres must not be damaged (flat) for the recharging to be any good

Bad news;
He was not too interested in retrofitting the Citroen spheres, saying it wouldn't be worth it and they wouldn't make any money on it. If we insist maybe we can see what it would cost for it to be feasible for them - and for us.

For your reference, their contact number is as follows:
Pleiades
UK: 44 1487 831239
Australia: 61 07 4161 2512

 

[agaisin]

They wouldn't make money on it? Do they realize that we only have two alternatives now and the cheapest is 350/each?:
1) OEM globes at 475/each (best possible price I know of)
2) B&B globes at ~400/each or ~350 each when all 4 are purchased

How much would it cost them, and how much would we be willing to pay. Personally at 100/pop for their (presumably) higher quality/rechargeable globes, I think a ton of people would be all in. At 150/pop I think a lot of people would still be interested. At 200+, perhaps interest would wane until/unless they are proven as a better alternative to the other 2 options.

Also, I'm a little concerned about recharging the OEM globes. I've heard/read that they are not rechargeable - well, they may be rechargeable but since they weren't designed to be, how long is the recharged life span... Also with shipping etc how's this work - I need to take them out and can't drive my vehicle until I get the new recharged ones? Turnaroudn time is critical for anyone using it as a daily driver.

 

[scottm]

When I looked into this for my Audi brake bomb, my concern was the integrity of the diaphragm. It was old, and probably failed, or would fail soon enough. Recharging it was a crapshoot. Of course, I planned to drill and tap my own refill hole, not much expense, but still it was a crapshoot.

 

[agaisin]

I think we're getting somewhere with this. Here's my guess on the replacement model: HAD,07-350-2X/200Z08C-4N12-BA

Wanna give it a try.

Here is the manual.

I'm sure B&B orders through here. Can someone here find the time to call the mfg on the pdf to ask for their recommendation on a replacement model. An engineer should be able to figure this out with the above manual.

Called McMaster-Carr but they don't carry the model you referenced or anything similar (in terms of M22x1.5 etc).

I called Bosch Rexroth and got one guy that said his english wasn't good and put on another person who's english was so good he could only respond with "no english"...

So, I'll email them and see how much the part you identified would cost and I'll post any updates.

 

[SerasLibre]

Guys - we've got it!!

I called Pleiades UK again and spoke with Phil this time. He CONFIRMED they adapt citroen spheres to fit our vehicles. Cost is 100 british pounds each! AND THEY ARE REBUILDABLE!! He also confirmed they fill to the proper front and rear pressures for the vehicle.

There is a 2-year warranty on all components, so any and all failures would be covered in that time.

There is a small catch however; They have never actually installed these spheres on a 100-series, but claim it worked for whoever they sold them to. I don't need any spheres at the moment, but I may consider (unless someone else volunteers) buying a set to make sure they work.

If you haven't absorbed the cost-savings yet, thats $620 for a set of four new rebuildable spheres! Less than half of the B&B price! Once they fail you can ship them back to the UK and for a nominal fee they could be rebuilt and returned to you - with a new warranty!).

Depending on how this pans out I may consider stocking these in the USA for distribution/sale to all who may be interested.

 

[uHu]

Do we have any further specs on the Citroen spheres. Thinking of:
- Capacity - 400 cc front 500 cc rear - if much smaller we could have a problem with bottoming.
- Threads - Do we need an adapter.
- Physical size - Do they fit, or do we have to move anything.

 

[eleblanc]

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?

The front gas chambers have a gas volume of 400 cc, and a pressure of 2.26 MPa (327 psi).
Rear chambers volume 500 cc and 2.65 MPa (384 psi).

 

[uHu]

uHu are you sure about the volume and pressure?

Yes. Double checked. That is: I'm sure that is what is says in the 1998 description of the new fantastic landcruiser, in the FSM.

 

[Texasoil]

these 'standard accumulators' will not fit into the attachment filling, will not fit into the space, and are not the proper charge pressure. It is not possible or cost effective to modify them.

This is why B and B Suspension LLC has custom manufactured replacement accumulators. There are NO 'standard' accumulators on the market that will work as OEM replacements. Of course , a knowledgeable hydraulics engineer can design and fabricate a remote mounted kit to make a 'standard' part attach, but there are no low cost standard units out there the correct size for the front

 

[Texasoil]

B and B Suspension LLC does not recharge old OEM parts--they are junk and non-repairable. We have our parts custom manufactured the the correct size to retain the factory 'spring rate'. No 'standard' unit that meets the front size exists, and any slightly large will not fit into the space or mount to the ride control valve assembly.Those that meet rear unit capacity will not fit in the space available or mount into the ride control valve assembly.

 

[pman]

B and B Suspension LLC does not recharge old OEM parts--they are junk and non-repairable. We have our parts custom manufactured the the correct size to retain the factory 'spring rate'. No 'standard' unit that meets the front size exists, and any slightly large will not fit into the space or mount to the ride control valve assembly.Those that meet rear unit capacity will not fit in the space available or mount into the ride control valve assembly.

I know your trying to boost your personal interests, but calling OEM components junk, especially when comparing them to the product your trying to sell, is not a good way to convince people on this forum to buy your product.

 

[Texasoil]

the volumes quoted here ARE NOT correct. B and B Suspension LLC MEASURED the actual volumes and our custom manufactured unit match OEM parts.

I am also going to research the potential of the Citroen spheres. The 'rebuildable' units were very heavy and much larger outside diameter because of the robust threaded joint and definitely will not fit in the space available. (I had and maintained a 1973 Citroen SM for over 24 years and am very familiar with their spheres. Citroen stopped using rebuildable spheres in about 1990 or so, going to all welded,not serviceable units)

 

[Texasoil]

I will repeat an earlier statement, used, old, failed OEM Toyota/Lexus accumulators are NOT rechargeable--they ARE JUNK only. I am NOT calling the new parts inferior in any way--only the one that have already one flat--they ARE junk

 

[SerasLibre]

From the research I have done I can confirm TAXASOIL's comments on failed accumulators being junk. If you plan on fixing a "flat" accumulator, its not going to happen. At this point the internal diaphragm is damaged and the unit will not hold a charge.

However, if your accumulator has NOT failed, and you manage to prevent it from loosing too much pressure (by refilling it regularly), you can significantly extend its life. Others that have done this claim that you should expect 2-3x the normal service life of the accumulators.

 

[Texasoil]

B and B Suspension LLC believes contamination of the AHC fluid is a significant cause of accumulator failure. We KNOW it is or rather WAS among our customers. Since we began Requiring owners test their AHC system fluid for contamination by the Water Reaction Test , and then cleaning up the contamination, there have not been ANY accumulator failures in those systems. We got blindsided by AHC contamination attacking the accumulator diaphragms. The source(s) of the widespread contamination is not known. We have reason to suspect some bad new fluid--either counterfeit or mis-manufactured-mis-filled but definitely not real, clean AHC fluid. There ARE several very similar products made by large oil companies and specialty firms, but Toyota will never 'approve' any but their own fluid for which they charge 3 prices or more. We are developing a list of those products and will post it this month.

Owners should test thir AHC system fluid using our Water Reaction Test (below.)
B and B Suspension LLC
AHC FLUID WATER REACTION TEST
1) Purpose;
AHC fluid is very light colored highly refined low viscosity petroleum oil. Its appearance is (prior to new fluid from 2009 on) light greenish to light straw colored, clear and transparent. New fluid sold from 2009 on is dyed a light red/pink in color to distinguish it from other products. The similarity in appearance to brake fluid, many windshield cleaner concentrates, and un-dyed ethylene glycol antifreeze concentrate has contributed to many instances of service personnel using these similar appearing fluids to top-off or refill the AHC fluid reservoir. Unfortunately, the ‘new color’ is nearly identical to that of ‘environmentally safe, non-toxic or RV water system antifreeze—propylene glycol) All of these common contaminating fluids are very detrimental to the ‘rubber’ components in the AHC system.

The diaphragms separating AHC fluid from high pressure Argon in B&B Suspension accumulators are made from a special ‘Nitrile’ compound formulated to retain flexibility and strength from -40 to + 180 F. These parts flex with every tiny bump and road roughness and thus are repeatedly stressed where they bend. The common contaminants mentioned above are VERY DETRIMENTAL to the diaphragm because they dramatically increase cracking from repeated flexing. Even very low contamination levels, barely detectable by this rough test, can reduce accumulator life by 75% or more.

This ‘Water Reaction Test’ is designed to quickly show if any significant amount of brake fluid, methanol, propylene or ethylene glycol are present in the AHC fluid where an accumulator failed unexpectedly. Note this contamination may have caused failure of the original accumulators before the present owner acquired the vehicle. Many Owners have experienced repeated failures of Dealer installed OEM accumulators following known system contamination and accumulator failure, even though ‘the system was flushed with new AHC FLUID EACH TIME.’ Draining the reservoir and refilling with fresh AHC oil, then flushing to the accumulator bleed screws leaves nearly 75% of the old oil and contamination in the struts and main pressure accumulators.

2) Test Procedure;
Prepare 3 glass pint jars with lids by thoroughly washing with detergent and then thoroughly rinsing to ensure all detergent residue is removed . Ideally the final rinse should be with distilled water. From the right front accumulator bleeder, catch approximately 4 ounces of the old AHC oil into one of the clean glass pint jars—BEFORE ANY ACCUMULATORS OR FLUID ARE REMOVED. Then into another clean jar, catch a similar 4 ounce sample from the right rear bleeder. Add two (2) ounces of distilled water to each jar with the samples. Cap and then vigorously shake both jars for thirty (30) seconds to thoroughly mix the oil and water and then place the jars on a flat stable surface and allow them to sit and settle. After they have settled for 30 seconds, take color photographs of each bottle, then again after 2 minutes , and again after 5 minutes. Take the photos close enough to clearly show the interface between oil and water layers. EMAIL all 6 photos to kebowers47@gmail.com and kvnedbow@gmail.com. Note: Depending on the vigorousness of the shaking, a very fine emulsion may form which may take several hours to fully separate, even for the new fluid. However, even very fine emulsions of uncontaminated fluid and water will show growing clear layers within 5 minutes.

 

[SerasLibre]

TexasOil,
I am working on an AHC wiki and would like to include this in there if you don't mind. Please let me know if it is ok to include this information.