Lost AHC Pump Prime

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G

Glock3540

Joined
Aug 18, 2018
Threads
4
Messages
28
Location
Mt. Juliet,Tennessee
Hello, I just replaced my four AHC Globe/Accumulators on my 2009 LX570. I've owned the vehicle for over 5 years. It has appx
115k miles and runs perfectly. It spent most of its life in the Houston area so there is virtually no underside rust.
I flushed the AHC appx 4 years ago and it has worked very well during this time. I like to keep my vehicles in top shape so I do all the
required maintenance, sometimes well before it is suggested I do so.
I'm very frustrated at myself at the moment. Today, after replacing the globes, I was bleeding the system. All was going well until I realized I let the
AHC fluid tank run dry so now my pump has lost it's prime. I've tried all I know how to do to get it working again.
I can hear the pump running but it is loud (I'm guessing it is due to losing it's prime). I've also bled the 5th accumulator hoping that would help but
to no avail. How do I get my pump "reprimed"? The tank is just above the Max fill line at the moment but the pump will not pick any fluid up.
I know I'll burn up the pump in short order but I'm at a loss of what to do.

Please Help.
Thanks,Brian
 
I dont have an exact link for you sorry— but it's in here somewhere. Someone else will likely hop in with a better answer.

forum.ih8mud.com

LX570 AHC “Basics” - Added as sticky thread for AHC Issues

Point of this thread is to serve as a repository for 200-series AHC info, including LX570 and LC equipped with AHC (in select global markets). Let’s begin with a theory. The 200-series LC (without AHC) and the LX570 (or LC with AHC) are like New York & LA. LC “purists” are like New Yorkers...
forum.ih8mud.com forum.ih8mud.com

It seems like the most reliable method is to run the pump in reverse to suck up new fluid. To run in reverse you just need to reverse polarity. If I remember correctly though, the member who has had success with this primed on their work bench by removing the pump.
 
tbisaacs said:
It seems like the most reliable method is to run the pump in reverse to suck up new fluid. To run in reverse you just need to reverse polarity. If I remember correctly though, the member who has had success with this primed on their work bench by removing the pump.
Click to expand...

I recall this as well. Alligator clips and any 12v battery direct to the pump leads. Or skip the alligator clips altogether!

Also, if you have techstream, you can clear the pump code a few times to allow it to keep running.
Lots of threads out there like this one:


SOLVED Help with AHC stuck in low position - https://forum.ih8mud.com/threads/solved-help-with-ahc-stuck-in-low-position.1076835/post-12883769
 
Thanks So Much for your help!
I followed one of these links and that led to another link that was able to help me.
I thought I had damaged/ruined my pump at first. After carefully taking it apart, I saw that most all parts looked new or almost new. I carefully reassembled and went through the bleed procedure several more times before success.
Most posters state they used Appx one 2.5L can of suspension fluid. I blew that out of the water! I used 3 1/2 cans total!😆
I bled each of the four new globes and the (5 accumulator as well) many times. I will say however, most of the fluid in my system is now pink instead of brownish pink so I don’t regret using all that fluid (I had already bled the system a few years back so it was still in pretty good shape).
The truck seems to ride better but not a night and day difference. It is not as choppy and seems a little more settled.
In the end I’m glad I changed out the accumulator globes and the system is well flushed.
Again, Thanks for your help.
Blessings, Brian
 
I first tried bench priming but could not get the pump to prime. After emptying and removing the reservoir, I disassembled the pump to see if it had any internal damage.
Seeing none, I reassembled refilled the reservoir and hooked it up to a 12V source and the pump primed almost immediately.
I had the filler cap installed the first time and when I opened the cap pressure escaped more than I was expecting. Im guessing with the cap installed it created a an internal vacuum when the pump was trying to prime itself? In any event, with the cap off it primed very quickly.
I then turned it up on its side and wiped down the flat area around where the hardline connects with alcohol. I then put a piece of gorilla tape over the area to keep it from leaking during the reinstall.
It worked great!
I love my truck and it is riding better than ever now.

I do have a question for the experts.
What are the OEM specs on how many seconds it takes to raise the vehicle from low to neutral and then neutral to high?
 
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