AHC Leak (Rusty Line) (2 Viewers)

[LexusSnob]

I saw this thread way back in October (AHC Leak Thread) when I was searching here because I had a similar issue. I thought it would be cleaner to start a new thread. I was just moving in to a new house at the time, in fact it was carrying a full load over the less than perfect road to my new house when this occurred. I have been preoccupied with getting the new house set up and things fixed up that I haven't spent much time looking at the LX.

Basically what happened is I parked the LX after bringing a bunch of stuff over to the house and the next morning the right rear was slammed and there was a big pool of AHC fluid. I let it sit for a while while I worked on other things and eventually moved it into the garage to get ready to work on it. When I did this, I moved it a total of 15 feet or so from right outside to in the garage. The AHC leveled itself out and raised the right rear. The reservoir is very low but not empty and it has been holding its height with nothing noticeable dripping on the garage floor for 2 months or so now.

Now it's finally at a point where I need to fix it one way or another and get it back on the road. The fact that is continues to hold its height makes me wonder if I didn't "overload" it with a full load and relatively high speeds over a bumpy road and that it released that pressure however it could and is "fine" now. But if I think about that for more than 1 second it doesn't make sense and I have not seen anyone mention anything about that in any posts or videos.

I finally got under the truck the other day and took some pictures. Clearly the line is rusted as hell and it was wet with a small drop forming. I dried it off with shop towels to see if it was from the original leak or if it is still leaking. I will post the pics below. I will also post some pics from today. As much as I want to convince myself otherwise I think it is more wet today than when I took the pics after drying it. I also circled a section where I think I could notice that if I pushed or pulled on the line a very small amount of fluid appear at the connection. It wouldn't drip out but just become visible.

It seems to make sense regardless to replace this line altogether, certainly at some point. I haven't had the courage to take it out on the road but I can honestly deal with a very slow leak for a while as this is obviously not a daily. I would not want to be topping of with this precious nectar that is AHC fluid for very long. But if I can get a couple passengers to the airport and around town for a few days that would be fine until I can get everything repaired. I'm thinking it is fine now because it is sitting in a garage on flat ground but once I start hitting bumps at speed and going up and down hills it will just spray out again. It also occurred to me that it is cold and maybe the AHC fluid is thicker therefore not spewing out until it warms up.

I bought a bunch of AHC fluid and an OBD II connector to run Techstream in preparation to work on this.

 

[LexusSnob]

Pics right after wiping off. You can see torn bits of blue shop towels.

 

[LexusSnob]

Pics from today, a few days later. The blue bits are clearly yellowed from absorbing fluid. This could just be leftover I missed before or newly leaked fluid.

 

[jsloden]

With the amount of rust in general it might be time to start thinking about converting to a traditional suspension. When one line starts to leak the rest aren't usually far behind.

 

[Zer0zg]

With the amount of rust in general it might be time to start thinking about converting to a traditional suspension. When one line starts to leak the rest aren't usually far behind.

You'd be surprised. I bought my truck in 2018 with two leaking lines (DS front, PS rear) due to rust. I replaced those two and left the rest alone since they didn't look nearly as bad and the job, particularly in the rear, is a total PITA. Kept the other lines handy just in case. 4 years of NY/VT winters and still going strong.

That said, I would be replacing that line sooner than later. Leaking only under high pressure is odd behavior for a rusty line, I'd expect that from the buna n seals on the shock/ram but can't see how a rust pinhole would reseal itself after an overload situation. I'd almost want to verify that it's not coming from the seal on the top of the shock and dripping down the line. Either way there is no way that you're replacing that seal without destroying the rusty line getting it out of the car unfortunately, so I'd have a new one on hand.

 

[LexusSnob]

Thanks for the replies all. I tried to feel around the top of the shock and it wasn't wet at all. It definitely seems slightly more wet along that line than previously. The obvious culprit at this point seems like it would be a rubber seal. Either way I suppose I need to order up a set of lines. I'd rather not spend a bunch more money than needed, but is it that bad to work on this where I should think about touching the globes and anything else "while I'm in there"? Globes seem pretty spendy to do just cuz but I'm open to thinking about it. The truck is at around 160k which is pretty for these in the grand scheme of things but obviously it's old.

Also, I bought 4 of the big cans of AHC fluid since it's not getting any easier to find. I'm assuming when I take this line of it's going to spew everything everywhere. Any idea if I need to have more on hand?

 

[suprarx7nut]

Thanks for the replies all. I tried to feel around the top of the shock and it wasn't wet at all. It definitely seems slightly more wet along that line than previously. The obvious culprit at this point seems like it would be a rubber seal. Either way I suppose I need to order up a set of lines. I'd rather not spend a bunch more money than needed, but is it that bad to work on this where I should think about touching the globes and anything else "while I'm in there"? Globes seem pretty spendy to do just cuz but I'm open to thinking about it. The truck is at around 160k which is pretty for these in the grand scheme of things but obviously it's old.

Also, I bought 4 of the big cans of AHC fluid since it's not getting any easier to find. I'm assuming when I take this line of it's going to spew everything everywhere. Any idea if I need to have more on hand?

If you're going through the trouble of replacing the lines, I would do the globes. $700 for a full set of OEM globes. It's only expensive if you pay the huge NA market markups at the dealer. International pricing is a fraction of NA market pricing.

 

[Zer0zg]

I got lucky and my globes turned out to be fine(this was at 180k, at 210 now), but you could always do a graduation test and see where you stand. Replacing them can’t hurt, but it’s not as if you need to remove them to replace the lines.

I’d think that 4 cans should be plenty. It will leak, but you shouldn’t be spewing as long as all the tires are off the ground, which they should be for safety anyway! You’ll probably loose more fluid flushing/bleeding the lines afterwards.

 

[Urtwob]

I got lucky and my globes turned out to be fine(this was at 180k, at 210 now), but you could always do a graduation test and see where you stand. Replacing them can’t hurt, but it’s not as if you need to remove them to replace the lines.

I’d think that 4 cans should be plenty. It will leak, but you shouldn’t be spewing as long as all the tires are off the ground, which they should be for safety anyway! You’ll probably loose more fluid flushing/bleeding the lines afterwards.

Hi ZerOzg

I have had a few AHC problems over the past 2-3 years. My truck is a 1998 LC100
So it’s not a young vehicle.
However it is in great condition for its years.

Now then, a little background,
I have a personal medical issue that has left me partially disabled.
So the AHC is so important for me. Especially being able to lower the truck to help me get in and out.

Now let’s go back 4 years.
Prior to buying this truck I had another LC100. We live and work on a farm.
I bought that LC100 back in 2001 with 60,000 miles on it. It was a 1999 truck.
I drove the vehicle until 2017 by which time I had 495,000 miles on it.

By this time the AHC was giving problems and to avoid writing a long story here I will get to the point, I listened to a lot of wise and wonderful views from many people.
Some knew what they were talking about and some didn’t. But one view I started to take on board was that I would be much better to take out the AHC and instal a conventional suspension.

Oh boy, what a mistake.
On all fronts,
But the main issues were,
1, I really missed the AHC for my medical needs,
2, despite all the wisdom to the contrary by the time I had installed the complete new suspension I had spent almost as much as I would have spent upgrading my AHC.

SO in every way it was a massive mistake moving away from the AHC.

To be very honest, I now realise I actually destroyed a wonderful piece of mechanical brilliance by doing what I did.

But there is a Caveat, You must know what you are doing,
You must be prepared to do a lot of research and you must find the right people who can provide certain skills.

Anyway, living in Ireland I had the added advantage that I could go to Mark Allen who had spent his life working on the manufacture and study of the Gas spheres used by Citroen and Rolls Royce to name but a few.

So this wonderful gentleman was able to manufacture and install 4 new gas spheres or Globes for roughly 1/2 the price of OEM parts.

The next issue is the issue that you have identified.
Badly rusted pipes.
The simple truth is that in most instances you can have pipes made up from hydraulic rubber hose type construction. Simply take the old rusted pipes off.
And take them to a local hydraulic hose repair centre.
They will make you up a replacement pipe that is a flexible hose type and they will fit the appropriate fittings to each end so that they will fit back onto your truck. In many instances the flexible hose is easier to work with.

For example,
I had very bad corrosion on the steel pipes that entered the top of my rear struts.

As anyone who has experienced this repair will tell you, there is not much room to get at those fittings at the top of the struts.

As a side issue here,
You can get at them with a lot of effort but it can be done.
However I simply drill a 30mm hole through my floor so as I could get at the nuts etc directly. I then had 30mm rubber Capps fitted into the holes to seal them up.

Now back to that particular repair,

The original steel pipe had a very shape bend at the top of the strut.
This pipe then entered a plate or block which was the securing plate to hold the steel pipe fixed onto the top of the strut.

I was able to “sweat” the old steel pipe out of this steel fixing plate or block. Then I had new stainless steel pipes made, that were bent into the appropriate shape to allow the tight fitment onto the top of the strut.
These small stainless steel bends were brazed into the original fixing plate/block.

The original fixing plate is made of very good steel and it is actually very thick as well. Internal of these fixing plates is a 9mm hole with small o,rings fitted internally. We replaced the o, rings and brazed the short stainless steel bends into these fixing plates. It required a special brazing material to affix stainless steel to metal.

So this is an example of why you have to find the right people.
However you will find them easier than you might think.
My local radiator repair shop had all the skills required.

Now back to the stainless steel bends,

I had the stainless bends made up first, I then had my local hydraulic pipe repair and pipe manufacture shop join the required length of flexible hydraulic hose to the stainless steel bends. And also had the appropriate fitting put on the other end of the pipe.

It all sounds complex and difficult.
It was not.

However,
The OEM replacement pipe for this was going to cost approximately £125 for each side of the car.
The pipes I had made cost me approximately £25 for each side of the truck.
And in my opinion having used stainless steel etc, the pipes I had made are actually a better build than the original.

So I now have four new globes, economically installed. Then I have two new pipes from the rear globes to the top of the struts installed economically.

And just last week I had two after market struts installed on the rear for just over 1/2 price of the OEM struts. To my amazement when they came from a highly reputable Japanese 4x4 parts company, the company guaranteed the struts, and the springs I bought from them, were up to the OEM specification. I have used this company for years and they have never let me down.

Anyway my friend,
I know I have written a long story but I just want to get word out there that the AHC is a brilliant piece of mechanical ingenuity. It is something you should cherish and the experience I have just shared will illustrate that if you are prepared to do a little research and a bit of leg work, you can sustain an aging AHC system for the trucks lifetime. And not at a high price, but it can be done economically.

It is, I admit, an illustration of the outplay of the adage,
“Where there is a will, There is a way”

And to conclude,
I have had to do much research but that task has been made almost effortless by this brilliant forum. Ih8mud forum is in my opinion a “World Class” source of ideas, skills and unbelievable highest quality information and intelligence. But most of all is the eagerness of fellow IH8MUD forum members to reach out and offer the highest quality suggestions and solutions.

Indeed I had a problem today after fitting my two new rear AHC struts, the truck ECU had put my AHC into fail-safe mode to prevent me from inadvertently damaging the AHC pump.

One of the fellow forum members was happy to both explain what my problem was and then in detail how I solve this problem but also provided links to appropriate PDF bulletins.

Ok,
That’s enough for now.
But please consider all I have reported here as it is sn awful feeling to find out that you regret taking off your AHC system.
It is an even worse feeling to find out you did so being under the illusion that the AHC was not sustainable in an older vehicle.

I hope I have demonstrated that that view is not always correct.

One final point,

Some people say that the AHC is not suitable if you are using your vehicle for heavy trailer work.

With a bit of care and consideration the AHC will work admirably in these circumstances but I am planning to add two simple air-bags inside my new springs.
After I have these installed I have the option to simply use an airline to put them up to the required pressure to support the springs and the AHC system when I am doing heavy trailer work.
And I do use my truck for heavy trailer work.

To my amazement a very reliable but simple air-bag system can be installed for less than £200

I hope I have helped by sharing my experience here. I do do in the spirit of “giving back” to my fellow forum members.

 

[Raj]

I hope I have helped by

Thank you. Thats a very detailed and inspiring experience. Mine is 2014 200 series and when AHC failed, I thought of changing it to standard suspension. Now I got it fixed but always have that fear, it ll break again and so not driving the car much. Your experience inspires confidence on the AHC system and the truck itself.

 

[Urtwob]

Thank you. Thats a very detailed and inspiring experience. Mine is 2014 200 series and when AHC failed, I thought of changing it to standard suspension. Now I got it fixed but always have that fear, it ll break again and so not driving the car much. Your experience inspires confidence on the AHC system and the truck itself.

Thank you.

I think it is a good thing to share all these scenarios on the forum. Ultimately sharing repair ideas might give hope and perhaps inspire solutions for someone else at a later stage.

 

[Kieron]

Hi I know this thread is a bit old but I’m in Cornwall north coast on holiday. I believe I’ve got a burst AHC pipe, reservoir tank empty
i need some TOYOTA AHC fluid asap and a garage to do the work can anyone out there throw me a life line please

 

[94SRUNNER]

Hi I know this thread is a bit old but I’m in Cornwall north coast on holiday. I believe I’ve got a burst AHC pipe, reservoir tank empty
i need some TOYOTA AHC fluid asap and a garage to do the work can anyone out there throw me a life line please

You may have better luck in one of the 100 Series Facebook groups. I know there are a few UK based Land Cruiser groups which might help you narrow/refine your search.

Try here as well - The Toyota Landcruiser Owners Club :: Index - https://www.tlocuk.co.uk/forums/