AHC Failure - drivable? Repair shop advice? (1 Viewer)

[tjb]

I've been through a million of these over the years, so I apologize for creating another. But it's difficult to find answers to specific issues/questions.

My AHC has failed - stuck in the flashing OFF now, code is C1762 - abnormal oil pressure for pump. My front height sensors are at -2" and -1.7". My rear is at -0.6".

1. Is it safe to drive in this state?
2. I'm not near my house/tools, the car was freshly fluid-filmed, it's freaking cold in Maine right now. Do I dare try my luck with the local Lexus dealer repair shop?

 

[tjb]

Update:

I ran the Abnormal Oil Pressure for Pump air bleed from the FSM (attached), and the truck groaned and fought to get back into N. (I didn't know when to stop the bleed, but did so after 45 seconds or so with the pump still running.)

It stayed there with one complete run around a short block.

h/t: @PADDO -
Post in thread 'AHC C1751 & C1762 Help/Recommendations/Suggestions'
AHC C1751 & C1762 Help/Recommendations/Suggestions - https://forum.ih8mud.com/threads/ahc-c1751-c1762-help-recommendations-suggestions.997555/post-11092142

 

[suprarx7nut]

That code normally means there's either air (empty reservoir or a bad bleed attempt) or nitrogen (a globe failed and is releasing gas into the fluid) in the system.

If bleeding fixes it and the problem returns, chances are high that you've got a bad globe (or two or three or four). A set of globes is $600-$1000 via carefully selected sources. Impex is the popular choice, especially now that the Yen is weak against the US dollar.

 

[tjb]

That code normally means there's either air (empty reservoir or a bad bleed attempt) or nitrogen (a globe failed and is releasing gas into the fluid) in the system.

If bleeding fixes it and the problem returns, chances are high that you've got a bad globe (or two or three or four). A set of globes is $600-$1000 via carefully selected sources. Impex is the popular choice, especially now that the Yen is weak against the US dollar.

I started the Impex trend here, I think. Installed mine three years ago.

Wondering whether that was a good move. The ones I got had no date stamp - had me wondering at the time.

I have foam in the reservoir, which leads me to suspect a bad globe.

Anyone else having problems with any Impex globes?

 

[Wheeliee]

Man that sucks! I just ordered some $650 japanese globes off ebay and I am so concerned they are knockoffs despite being in toyota boxes. I didnt know a date code is a good indicator. Ill have to check that out when they arrive. You may know this and part of it was mentioned..FSM says that code trouble areas are AHC pump/motor, Fluid pressure sensor, AHC motor relay or fluid empty.

 

[Hokie LX]

No reason not to buy globes from Impex vs. questionable authenticity from other sources. I ordered some last year for my truck.

OP, I also had that code on my truck but was due to accidentally putting new fluid in from the old plastic AHC fluid bottles which were known to shed the inner lining. This clogs up the pump and causes low pressure. I ended up disassembling and flushing the pump and problem went away after putting new globes on.

Changing the globes is pretty straightforward for basic mechanic skills and it seems you already know your way around Techstream which is good. I'd do a graduations test if the truck will move from H to L and then replace globes if needed. Use fluid from metal cans only...I believe they come in 2L cans.

I drove my truck with this condition for a couple days and it caused it to drop to L on the highway...other than a rough ride and compromised handling from the lack of dampening, it is "driveable". I would avoid the dealer unless you want to fork out thousands of dollars for an otherwise "cheap" repair. From what I've read, most dealers don't understand AHC anyways and will a) quote very high to try and deter you from pursuing the work, or b) flat out reject the job.

 

[tjb]

No reason not to buy globes from Impex vs. questionable authenticity from other sources. I ordered some last year for my truck.

OP, I also had that code on my truck but was due to accidentally putting new fluid in from the old plastic AHC fluid bottles which were known to shed the inner lining. This clogs up the pump and causes low pressure. I ended up disassembling and flushing the pump and problem went away after putting new globes on.

Changing the globes is pretty straightforward for basic mechanic skills and it seems you already know your way around Techstream which is good. I'd do a graduations test if the truck will move from H to L and then replace globes if needed. Use fluid from metal cans only...I believe they come in 2L cans.

I drove my truck with this condition for a couple days and it caused it to drop to L on the highway...other than a rough ride and compromised handling from the lack of dampening, it is "driveable". I would avoid the dealer unless you want to fork out thousands of dollars for an otherwise "cheap" repair. From what I've read, most dealers don't understand AHC anyways and will a) quote very high to try and deter you from pursuing the work, or b) flat out reject the job.

Thanks for the advice.

I did a couple of flushes with the plastic-bottled AHC fluid.

I have ordered a bunch of stuff from Impex without a problem. Fwiw Amayama has globes for ridiculously low prices right now.

I was in a warm garage when I swapped them out before - Maine is warming up but it ain’t warm enough now to be doing this.

 

[tjb]

I didnt know a date code is a good indicator.

I’m not at all sure that it is! Just noticed that the globes didn’t have one and thought it strange.

I’ve bought a bunch of stuff from Impex and not noticed any problem before. I’ve put just under 70,000 miles on the new globes.

 

[tjb]

Flushed the fluid - what a sh-tshow. Pro tip: When it's very cold (30s F), the plastic tube can't be easily pushed over the accumulator nipples, and none of the held. I took many showers.

The fluid from all five bleed valves and the reservoir was a foamy tan milkshake. I believe that is at least one blown globe, correct?

I got back into 'N' with the new fluid, but it wasn't happy about it. A lot of pump running, some air clearing in the pump with the FSM bleed procedure.

If one globe is blown, can the car be driven? I'd at least like to get it home to work on it there - about 150 miles.