Lexus LX 570 AHC fluid leak (1 Viewer)

[Abdulmuzib85]

Hello everyone, I have question;

Lexus lx570 2013 had sudden leak fluid rear bottom car after which told hydraulic need be replaced (AHC fluid leaking after mechanic dropped in tank). Dealer asking for $900 for new replacement? Is that average cost or am I getting ripped off?

 

[UCrazyKid]

What ever happened here? I have a leak from the AHC compartment (rear passenger wheel well) that seems to have stopped. It was an extremely hot day 97°F and very humid. After an hour drive, parking on a steep grade nose down, and the AHC dropping to low for easy exit. A puddle formed on the ground from behind the wheel.

Could it be the fluid expanded with the heat and the combination of the car lowering (fluid moves back to reservoir) and being on a hill the reservoir over flowed? There is no change in driving/ride characteristics.

 

[tbisaacs]

The inlet of the reservoir is on the bottom of the tank. I would check the hose clamps there. The filler neck has several vents and screens and seals in it. I would expect that if anyone of those were loose, fluid could escape when comfort access is on as the fluid would be at its highest level.

 

[Bunga]

Exactly. Where is it leaking? Left, front? etc.

 

[UCrazyKid]

 

[tbisaacs]

View attachment 2036212

That’s the door for the reservoir. Pull it off and you’ll see the filler neck. If you crawl underneath and sit a flashlight on top of your spare tire you can get a better look at the tank.

 

[LXinOBX]

There a post I put up earlier this year (crazy wonky connection or I'd post it up) about our AHC fail due to a corroded fluid line.

 

[Bunga]

There are several places for failure in there, as noted above. Most are pretty easy fixes given how high up the drips are coming from. (If it had ruptured it would just all come out the bottom, so likely a return line.) But it seems well-protected, so who knows.

I use a large LED light up in that space by the spare tire and under the edge of the trim to backlight it. (Same way I fill it- although I once left a flashlight there and it came off on the road...) Look for cracks and shifted hoses. There are some lines on the translucent plastic tank for filling levels, all set from the N height position.

I would not use the system, including comfort lowering, until you have a good handle on the problem or it can be expensive to get it all sorted out.

The pressure fittings/adjuster/relief are just carbon steel and rust like hell. There are some horror show pictures here, and then the fittings seize or break when used. I use LPS 3 and spray it on. It collects dust, but no rust.

To your earlier question, that tank is huge in comparison to the volumes, and mine never spilled a drop in the hot desert at crazy angles. The "cap" is just a simple twist bayonet that somebody could have just slid on but not turned, but even then it is mounted very high- so maybe just return fluid. Twist it back into place. The fill lines are hard to see, so in theory it could have been way overfilled.

There are several posts on the bleeding-filling, once you learn to do it, no problem and simple maintenance.

 

[UCrazyKid]

There are several places for failure in there, as noted above. Most are pretty easy fixes given how high up the drips are coming from. (If it had ruptured it would just all come out the bottom, so likely a return line.) But it seems well-protected, so who knows.

I use a large LED light up in that space by the spare tire and under the edge of the trim to backlight it. (Same way I fill it- although I once left a flashlight there and it came off on the road...) Look for cracks and shifted hoses. There are some lines on the translucent plastic tank for filling levels, all set from the N height position.

I would not use the system, including comfort lowering, until you have a good handle on the problem or it can be expensive to get it all sorted out.

The pressure fittings/adjuster/relief are just carbon steel and rust like hell. There are some horror show pictures here, and then the fittings seize or break when used. I use LPS 3 and spray it on. It collects dust, but no rust.

To your earlier question, that tank is huge in comparison to the volumes, and mine never spilled a drop in the hot desert at crazy angles. The "cap" is just a simple twist bayonet that somebody could have just slid on but not turned, but even then it is mounted very high- so maybe just return fluid. Twist it back into place. The fill lines are hard to see, so in theory it could have been way overfilled.

There are several posts on the bleeding-filling, once you learn to do it, no problem and simple maintenance.

This is terrific information. I’ll dig into it this weekend. In the meantime I have not seen anymore leaking on the ground and it drives fine. I’ll keep the height neutral until I can look at it. It’s due for service as I am nearing 120,000mile (it was flushed at 60k) It was a Texas car until a year ago so hopefully no rust. I’ll treat the fittings as you suggest to prevent any further rust. Thanks!

 

[Reg Wang]

went in two days ago to have radiator leak checked (seems to be a known defect with 2008-2011 200 series, mine is the 2011 LX570), replaced radiator and serpentine belt pulley system (101750 miles). Then when the car was in the air, mechanics noticed corrosion of the AHC pipe at the rear driver side, above the exhaust. The AHC pipe throughout the car is exposed, seems coated with teflon, very very durable, except this small section, less than a foot, where they had to protect it from the exhaust and used a foil underneath, but the foil is open on both ends and hence became a tray for salt! Leadning to leaking of this small area.

Now I'm waiting to hear the cost of fixing it. I may consider selling it for a Tacoma, no hydraulics, just plain truck, ideally I'd want to keep the LX and also buy a LS400, but can't afford right now.

 

[lx200inAR]

This has come up a bunch lately. It seems to be the most common line failure. From what I understand, it’s not too bad to repair.

 

[Reg Wang]

good to know!! I asked my mechanic to think up a custom fabricated aluminum shield that both protects and not collect salt.

 

[Reg Wang]

good to know!! I asked my mechanic to think up a custom fabricated aluminum shield that both protects and not collect salt.

my guy did it! using a union connector. but now the AC may become the straw. Passenger side warm air while driver side cold, mechanics fears it's the actuator or valve mechanism failing and doesn't want to get involved unless i'm prepared to pay top dollar for 11 hours of dash ripping work

 

[lx200inAR]

Did you try turning off dual zone and setting cool to max? Setting to max will bypass some sensors and force to blow cold if it can. That might narrow down an electronic issue; rather than mechanical.

 

[Reg Wang]

Did you try turning off dual zone and setting cool to max? Setting to max will bypass some sensors and force to blow cold if it can. That might narrow down an electronic issue; rather than mechanical.

so, went to

Did you try turning off dual zone and setting cool to max? Setting to max will bypass some sensors and force to blow cold if it can. That might narrow down an electronic issue; rather than mechanical.

so, went to turn off the dual zone (4 zone) and yes, both sides now blow air of the same temperature (whatever it is that i set). I did not then test with the 4 zone back on. I should do so now. but may I ask, what is the rationale behind doing this again?

 

[Reg Wang]

update: just played around with the settings.
1. 4 zone is turned on
2. regardless of the air circulation mode (intake from outside, internal circulate or Auto), the passenger side air temp responds to the temp adjustment, i can feel the difference between 70 and Lo.
3. Big discovery: when switching from outside to internal, I can hear a low "thud" sound coming from the glove compartment. Repeated a few times, always thud every time.

So I guess is this a problem? because i can't seem to replicate the "warm air" problem anymore, but this thud sound suggest some mechanical valve thing is moving?

 

[lx200inAR]

Lie thud is not necessarily bad. Open your glove box and pop the little cover in the back off. There is a domed flap that moves to allow the AC to switch between recirculating and outside. Once the cover is off, hit the recirc button and see if the flap moves. If it does, you are good. If the thud is caused by some broken things banging against each other, then welcome to the party. The domed flap gets broken by many a service tech who forces the flap to change the cabin filter, rather than hitting the recirc button to move the flap out of the way.

 

[lx200inAR]

so, went to

so, went to turn off the dual zone (4 zone) and yes, both sides now blow air of the same temperature (whatever it is that i set). I did not then test with the 4 zone back on. I should do so now. but may I ask, what is the rationale behind doing this again?

My reasoning is that the Lexus uses ambient air temp to decide how cool to make the AC output. If there is something wrong with that sensor, setting the temp all the way to min will over ride the sensor reading and put the AC into max cool mode.

 

[Reg Wang]

When my independent technician ran a diagnostic, there was indeed an error code about some solar sensor. He wasn't sure what it meant and where this solar sensors are. He erased the code, but, if it's really just a matter of sensor error, I think that should be a LOT easier to fix.

 

[Reg Wang]

ok, update;
opened the glove box and removed the slim horizontal door to expose the cabin air filter chamber, the "accordion" cover type of thing attempts to lift up but remains in shut position. i played with it a bit, lift up, shut, lift up. by the way, my cabin air filter is stuffed with leaves...maybe a contributing factor.

anyhow, how come that accordion trap door is not opening when switching from outside to recirculation? bad news?