AHC Failure on '11 570 (1 Viewer)

[RatherBeRacing]

I was driving with 4k lbs trailer when I saw bunch of smoke behind me. Pulled to the side and saw that liquid was pouring over the exhaust on the driver side in the rear. The height was normal at that point. I continued for another 200 miles, the smoke came again couple times (I guess as it was trying to adjust) and the "Check AHC" warning come one. Poked and the car would not could not quite tell where it was coming from exactly as it was pouring on the cross member and then going all over the place. After I dropped trailer off the rear was up high, turned the car on and it lowered it down by pouring more liquid out. Now the front is sitting low as well.

Taking to mechanic tomorrow. Will give an update.

 

[BRob2756]

I was driving with 4k lbs trailer when I saw bunch of smoke behind me. Pulled to the side and saw that liquid was pouring over the exhaust on the driver side in the rear. The height was normal at that point. I continued for another 200 miles, the smoke came again couple times (I guess as it was trying to adjust) and the "Check AHC" warning come one. Poked and the car would not could not quite tell where it was coming from exactly as it was pouring on the cross member and then going all over the place. After I dropped trailer off the rear was up high, turned the car on and it lowered it down by pouring more liquid out. Now the front is sitting low as well.

Taking to mechanic tomorrow. Will give an update.

Hate it for you man. Had you ever serviced fluid or system?

 

[TonyP]

Was there excessive tongue weight?

 

[purdytj]

Yikes. I'll be watching this thread as we tow a 5,000 travel trailer about once a month.

 

[RatherBeRacing]

Hate it for you man. Had you ever serviced fluid or system?

Thanks. Nope, only 73k miles. I guess now it will be serviced.

Was there excessive tongue weight?

Although don't know for a fact, I highly doubt it.

 

[Ali FJ80]

Maybe the shock or line leaking. Access to the reservoir is in the back passenger wheel well, towards the back. Two 10mm bolts. Leak seems somewhat slow if it went 200 more miles. You can probably top it and drive it to the shop but you need the toyota AHC fluid.
Good luck

 

[RatherBeRacing]

Update:

Mechanic found two lines raptured and had to spend some time with Lexus parts department to figure out which ones he needs to order. Lexus guy mentioned to my mechanic that he's seen this especially for one of the lines, which attaches with a bracket that rusts together with the line.

800 bucks for two lines to be replaced. Hopefully not much to this than that.

 

[BRob2756]

Update:

Mechanic found two lines raptured and had to spend some time with Lexus parts department to figure out which ones he needs to order. Lexus guy mentioned to my mechanic that he's seen this especially for one of the lines, which attaches with a bracket that rusts together with the line.

800 bucks for two lines to be replaced. Hopefully not much to this than that.

Nice! That seems like best case scenario for you - glad you don't have to replace the whole system.

You mind me asking - is Lexus covering?

 

[RatherBeRacing]

Im not using Lexus dealer, I went straight to an Indy shop. I'm not sure why Lexus would cover as it's out of warranty and I didn't buy it from Lexus dealer or do any service business there. In my high cost area, dealer will try to rip you off on simplest things so I avoid them.

 

[TeCKis300]

Glad you found the issue. Hope your indy is good and familiar with the AHC system. As many Lexus dealerships have been known to screw up the system out of ignorance.

 

[mark71]

Is this the first AHC failure on this forum? You don't hear about it often, so just curious.

 

[TeCKis300]

Yet this will be enough for everyone to decry AHC and denounce LX's...

Yet how many threads have we seen on BP51 this, Icon that...

Just saying...

 

[purdytj]

We really like the AHC. It makes for a very comfy ride and compensates for cargo loads of gear and/or people. The tongue weight on our trailer is about 400 pounds (but we do use a weight distribution system) and the truck handles it so nicely.

 

[jblatl]

My brother and father will only buy the LX trucks because they love the ride and never plan on modding them. I find that the system in the two trucks that are in my immediate family seem to be rock solid. I on the other hand have already purchased the BP-51 setup and have a different road for my truck.

 

[tabraha]

We really like the AHC. It makes for a very comfy ride and compensates for cargo loads of gear and/or people. The tongue weight on our trailer is about 400 pounds (but we do use a weight distribution system) and the truck handles it so nicely.

The AHC on my '99 LX with 250k miles on it still works great. MY dad was towing a travel trailer with it this past year and still no issues. OP has me wanting to crawl under the 570 and look at the lines for points where mud could cake and cause premature corrosion for sure though. My 08 has never seen mud from what I can tell on the undercarriage but it hasn't been in my possession very long so that will change LOL. My 08 570 with 155k on it rides like a cloud. If it matches the longevity of my 470 I'll be a happy camper. Fluid in the reservoir looks pretty clean so it appears to have been changed at least once in it's lifetime. I know when I did mine on the 470 at 150k it was black.

 

[RatherBeRacing]

Is this the first AHC failure on this forum? You don't hear about it often, so just curious.

Actually, if you go to Lexus forum, seems more common that one might thing and usually due to corrosion. Most failures are on LX470 due to age, but I guess 570 are not immune to rust either. I was stunned to see how much rust is under there, although most of it is surface rust. I might get under there with film spray. Any other advice?

 

[RatherBeRacing]

Another update:
So after getting one wrong line from Lexus and then waiting to get the right one, the two lines were replaced and system was pressurized and there was another line that was leaking at the fitting. So one more line is going in tomorrow hopefully that will be it.

The mechanic tried to see if those parts could be replaced under corrosion warranty at no avail Hopefully this was just a result of high use during harsh winters out here in NJ.

Side note, the system should be flashed every so often for the same reason as brake lines to get rid of any moisture. Otherwise it can start rusting from inside.