AHC Leakage help

IceStorm · Aug 4, 2014

My LC 100 1999 with AHC seems to have sprung a leak. I am driving out in the country about a 100 miles or so away from the next Toyota dealer. The Car now sits in the Low position and the resevour us empty. It does try to raise it self and then gives up and the off light on the AHC blinks. The leak is on the left hand side towards but not at the front left accumulator. There is some sort of a unit there (that is not on the right side just the left) at first it looked like a small resoivour tank but now I am not sure (see attached pic) anyway the leak seems to be coming from above that unit. Is it ok for me to drive the car to the next Toyota dealer, not sure if the local country mechanics have what it takes to fix this and I am sure they do not have the AHC fluid on hand.

Thanks in advance.

hkeller · Aug 4, 2014

The vehicle has 5 accumulators. 4 are damping force actuator accumulators. 1 is the height control accumulator. The height control accumulator gives the system the ability to dump large amounts of AHC into it quickly. This appears to be leaking on your truck. Are you riding on the bump stops on the front a-arms? If so, I'd take it slow and avoid bid bumps, since you essentially have no suspension travel. There is no aftermarket replacement part.

IceStorm · Aug 4, 2014

Thanks for the information hkeller. All 4 wheels are at the stops. Guess we will be taking it slow on the way back.

IceStorm · Aug 4, 2014

hkeller. If I was to overhaul the whole system (I already have new shocks on the rear) would the AHC globes and new shocks be close to a good overhaul?. Also I am in Iceland, my syster lives in Atlanta and is flying over next month. Do the LX-470 parts fit the LC 100? Price in U.S compaired to Iceland is about half.

Thanks again

hkeller · Aug 4, 2014

Icestorm - There are some folks on here much more knowledgeable than me about AHC, like "uHu" and "spressoman" (sp?). Before you start throwing expensive parts at it, you probably want to due some research and try to narrow done your issues. Most folks, when the AHC system goes bad, simply remove it and replace with a standard 2 inch lift. Do some search in the forums. There is much to learn about AHC.

There is much more to go bad than what you list. I'd hate for you to replace everything you list and that still not fix the issue. Good luck. Let us know how it goes.

uHu · Aug 4, 2014

Yes. The AHC parts of the LX470 are the same as on the LC100, all years.

You really have to love the AHC in order to be be willing to spend money on keeping it running. (Like I do...)
As said above, there are many threads on this here on mud.

Generally, on a 1999, you could (or should) already have changed the 4 accumulators (globes, spheres, gas-springs), 2 coil springs, 3 height sensors, 4 shocks. And might have changed the pump and the cylindrical accumulator (your problem area). All parts are generally expensive. Over all, it is cheaper to ditch the ahc and install 4 normal springs and shocks.

Your problem might be rusted pipes, just as well as a leaking accumulator.
Driving with no AHC pressure is really not recommended. You are on your bumpstops, and that puts a lot of strain on the front A-arms; in addition to not having any suspension or damping. If the road is completely even, and you keep the speed down, it could be doable.

This system is in constant need of maintenance, together with the hand-brake and the rear locker, particularly on salted roads.

IceStorm · Aug 5, 2014

Thanks again for taking the time to respond. Hope it is the pipes. I will repost here with pics once I have the truck up on a lift to inspect.

IceStorm · Aug 6, 2014

Update. Got the truck on a lift. After cleaning all the crud and oil I could not find any problems all seemed well. So lowered the truck back down and we poured some AHC fluid in to the tank and started the engine. Low and behold there was a pinpoint squirt of oil from the line just above the accumulator. New pipes are in order. Not the end of story, in Iceland roads are salted during winter, and cars are generally well protected with extra rust protection applied in Iceland. And my truck is no exception, however just above the accumulator there was none, probably a hard to get to area, and there and only there the pipes where rusted. So rusted in fact we could not get them unscrewed from the accumulator, and the accumulator was stuck to the body with 4 screws, 2 of whom where on the top of the chassis (Hope I got that work right) and we could not get to them in any way shape or form. So after many attempts, like customizing a spanner by bending in to fix we finally deiced to got the accumulator out. the pipes where rusted to it anyway so I would have the option of getting a used or new one or simply converting the truck to normal suspension. So now I am on the hunt for a used one to replace the one we cut out. If I can not do this for reasonable money I will convert the truck to normal suspension and be done with it.

IceStorm · Sep 24, 2014

Finally decided to refurbish the AHC unit. Had to heat the old rusty pipes a lot to get them out of the unit. Got a mechanic to drill out the bleed nipple and replace it, (Fortunately) I had him do it because as soon as he drilled out the old rusty bleed nipple he got sprayed with AHC fluid exiting the unit under high pressure. Once I had the unit back I had new pipes made to fit and we proceeded to place the unit back in the car. With the help of a good friend we welded the unit back on the brackets we had previously cut to get the unit out of the car. Spliced the new pipes to the old ones, poured the AHC liquid into the resourvar, started the car, ran it for a bout a minute. AHC warning lights did not light up and the car was in the low position. Raised the car and it rose with out any problems. Raised it to high and then back to low and then once more. No problems and all seems well. I am not sure if I need to bleed the system or if the air escapes naturally when cycling the system up and down.