Sorry for the long and rambling word vomit, I’m not a great writer:
-I have read ABC's and so many AHC posts but still having issues with air entrainment.
I’m having some issues with my AHC. No damping at all in the front, little in the rear. I replaced the globes in January, so probably less than 5k miles ago.
- I do have Techstream, pressures are a touch high but I need to re-index torsion bars to properly adjust to base levels.
PO did little AHC maintenance, but it had fluid(dark) and no leaks.
It had no damping but did go L-N-H as usual, quickly with no odd pump sounds.
Replaced globes and flushed/bled system(probably poorly). Everything worked perfect after that and the ride was amazing, 14 gradations on tank.
Fast forward a few months and it spent 3 weeks this June not being driven while I was out of town, also sat with a flat tire from a slow leak that it must have had during that time. After I got back in town I replaced the tires and the ride was bad, classic front end pogo with no damping.
I first tried bleeding the 4 corners. Some foamy fluid came out, then the hose slipped off when bleeding the left drivers side rear globe. I had a huge mess of AHC fluid on the garage floor before I could finally get it closed. It may have ingested air through the bleed screw then, not sure.
I got it all buttoned up and it raised to N, I drove around the block and then raised to H, seemed to go well. Then as I was backing into the driveway, the rear end lost all pressure and dropped to the L. The truck had a huge squat and so I pulled into the garage and tried to raise again. Got dreaded 1762 abnormal pressure code.
I assumed I had gotten lots of air in it and so I bled again and decided to flush again with a new can of fluid. Went through regular flush process and tried to raise it to distribute fresh fluid, it wouldn’t raise(1762 lockout). Also, the ride height accumulator did not have any fluid in it when I attempted to bleed it. Tried Active Test procedure, nothing. Direct connected pump, ran fine, disconnected pipe from pump body and direct pump drive, good fluid came out in a steady stream.
I kept clearing the code and attempting to raise it, but it would just immediately code and lockout again. Then(very angry), I cleared code again and pressed the button to raise and violently shook the truck side to side in rage, ha. The code didn’t come back, at least not while it was being shaken. It also didn’t raise at all, and coded as soon as rocking ceased.
Based on that, I jacked the back end up about 3” by the pumpkin and cleared the code and pressed button. I was outside truck and I rocked it side to side again very roughly, and it started to slowly rise. No more 1762 code, I cycled it a few times L-N-H-N-L and back.
I let it sit for a day to think about what it had done. I came back to it and bled every corner into a catch bin, then used my chamber vacuum seal machine to degas the fluid and pour back into the tank. I probably did this 8 times, and damping never happened again.
It does raise very fast, 8 seconds or less for each step, but only 6-8 gradations on the tank. Also the returned fluid when lowered is foamy. I will let it sit in low while foamy fluid lets the trapped air out, then raise to N, sit, then raise to H, sit, and then back to L, still foamy and consistently foamy with every cycle. It doesn’t appear to get better or worse.
Through exhaustive reading here, I am thinking the screens are inducing air entrainment because they are maybe contaminated with gunk from the old fluid?
The LX is my DD, so I am hoping to get it fixed asap.
I just don’t know the logic tree that the AHC ECU uses. Why would it lock out any damping ability?
Or what checks does it have that would lock out damping ability in the front, but not throw an AHC system code?
If just from air compression in the dissolved fluid, or anywhere in the system, why would the front lock out and be hard as a rock, and the back end have some damping and some give to move up and down? If it was just air and physics, it should affect front and back equally.
I will have to order more AHC fluid since I am out now from the last flush, in case I spill too much emptying the tank. But while I wait for that, is there anything I am not thinking about that it could be? With no leaks, there shouldn’t be any air able to enter the system other than at the pump, right? The screens seem like the only logical last resort to fix the air getting into the system.
On that, what’s the time estimate do you think to drain/remove/clean/replace and prime? Maybe 3 banana and 2 hr project?
I appreciate any help this fine group may have, I really love the AHC ride and do not want/cannot afford to replace with non-AHC. Thank you!
-I have read ABC's and so many AHC posts but still having issues with air entrainment.
I’m having some issues with my AHC. No damping at all in the front, little in the rear. I replaced the globes in January, so probably less than 5k miles ago.
- I do have Techstream, pressures are a touch high but I need to re-index torsion bars to properly adjust to base levels.
PO did little AHC maintenance, but it had fluid(dark) and no leaks.
It had no damping but did go L-N-H as usual, quickly with no odd pump sounds.
Replaced globes and flushed/bled system(probably poorly). Everything worked perfect after that and the ride was amazing, 14 gradations on tank.
Fast forward a few months and it spent 3 weeks this June not being driven while I was out of town, also sat with a flat tire from a slow leak that it must have had during that time. After I got back in town I replaced the tires and the ride was bad, classic front end pogo with no damping.
I first tried bleeding the 4 corners. Some foamy fluid came out, then the hose slipped off when bleeding the left drivers side rear globe. I had a huge mess of AHC fluid on the garage floor before I could finally get it closed. It may have ingested air through the bleed screw then, not sure.
I got it all buttoned up and it raised to N, I drove around the block and then raised to H, seemed to go well. Then as I was backing into the driveway, the rear end lost all pressure and dropped to the L. The truck had a huge squat and so I pulled into the garage and tried to raise again. Got dreaded 1762 abnormal pressure code.
I assumed I had gotten lots of air in it and so I bled again and decided to flush again with a new can of fluid. Went through regular flush process and tried to raise it to distribute fresh fluid, it wouldn’t raise(1762 lockout). Also, the ride height accumulator did not have any fluid in it when I attempted to bleed it. Tried Active Test procedure, nothing. Direct connected pump, ran fine, disconnected pipe from pump body and direct pump drive, good fluid came out in a steady stream.
I kept clearing the code and attempting to raise it, but it would just immediately code and lockout again. Then(very angry), I cleared code again and pressed the button to raise and violently shook the truck side to side in rage, ha. The code didn’t come back, at least not while it was being shaken. It also didn’t raise at all, and coded as soon as rocking ceased.
Based on that, I jacked the back end up about 3” by the pumpkin and cleared the code and pressed button. I was outside truck and I rocked it side to side again very roughly, and it started to slowly rise. No more 1762 code, I cycled it a few times L-N-H-N-L and back.
I let it sit for a day to think about what it had done. I came back to it and bled every corner into a catch bin, then used my chamber vacuum seal machine to degas the fluid and pour back into the tank. I probably did this 8 times, and damping never happened again.
It does raise very fast, 8 seconds or less for each step, but only 6-8 gradations on the tank. Also the returned fluid when lowered is foamy. I will let it sit in low while foamy fluid lets the trapped air out, then raise to N, sit, then raise to H, sit, and then back to L, still foamy and consistently foamy with every cycle. It doesn’t appear to get better or worse.
Through exhaustive reading here, I am thinking the screens are inducing air entrainment because they are maybe contaminated with gunk from the old fluid?
The LX is my DD, so I am hoping to get it fixed asap.
I just don’t know the logic tree that the AHC ECU uses. Why would it lock out any damping ability?
Or what checks does it have that would lock out damping ability in the front, but not throw an AHC system code?
If just from air compression in the dissolved fluid, or anywhere in the system, why would the front lock out and be hard as a rock, and the back end have some damping and some give to move up and down? If it was just air and physics, it should affect front and back equally.
I will have to order more AHC fluid since I am out now from the last flush, in case I spill too much emptying the tank. But while I wait for that, is there anything I am not thinking about that it could be? With no leaks, there shouldn’t be any air able to enter the system other than at the pump, right? The screens seem like the only logical last resort to fix the air getting into the system.
On that, what’s the time estimate do you think to drain/remove/clean/replace and prime? Maybe 3 banana and 2 hr project?
I appreciate any help this fine group may have, I really love the AHC ride and do not want/cannot afford to replace with non-AHC. Thank you!
