Not sure where my mind was today, but I messed up PADDO's AHC flush method. First a little background.
My new-to-me LX was low on AHC fluid. Because of this I considered a ruptured damper assembly (though the ride seemed fine), but I decided I'd go ahead and flush it and then investigate further based on results and techstream diagnostics.
My first error was due to me trying to do it from memory. After siphoning the fluid and filling the reservoir, I started the engine and raised the vehicle from low to normal before beginning the bleed. Other than flushing more fluid than necessary, I don't think this would make much difference. I mention it just in case. I added a bit more to the reservoir to make sure I didn't drop too low.
Observation: The fluid had the entrained gas (micro-bubbles) in it. I think this occurred at each bleed point on the driver side, but mostly improved by the time each bleed was complete.
I then started the engine (already in normal, mind you) and the system pressurized and raised. I then moved on to the passenger side to do the slight bleed over there. That fluid was clear except for maybe a few bigger bubbles at the beginning.
I guess I should have stopped here, but I decided to go back and do a similar slight bleed back on the driver side since I knew there had been a lot of entrapped air the first time. I started at the rear (pretty clear like I had seen on passenger side). This is where things went a bit off the rails.
I moved to the height accumulator, but nothing at all came out. I was confused and thought maybe I was having an issue with the bleeder valve. I turned it a bunch both ways and sort of lost track of how loose or tight it was, but got worried I'd back it out all the way (if that's possible).
I decided to call that off and close it up, OR SO I THOUGHT. I can't explain why, I guess since nothing ever bled from there on that attempt, but I didn't think it was open. Obviously I should have been sure it was completely closed, but I didn't. You may now guess where this is going.
I get in the truck thinking I'm done. Turn on the engine. Height adjustment begins and then acts funny, continually adjusting up and down. At this point I realize what's happening and shut off the engine. Big puddle and spray from the height accumulator. It was not closed, obviously. Clean up and close it, then add what's left in the third bottle to the reservoir which is now pretty close to the bottom. Knowing that, I turn AHC off, but at some point I guess it came on again and again lowered the level to very near the bottom of reservoir as it adjusted itself.
OK, here are my thoughts and main questions..
Besides needing to add more fluid, I'm concerned that air got in the system. Between shutting off the engine thus stopping the geyser from erupting, and closing the valve completely shortly thereafter, the height accumulate valve was open to the air. I'm not sure exactly how it works, but I assume some air could have entered. If so, will bleeding that accumulator solve the problem, or will a comprehensive bleed be required?
Similarly, the reservoir got pretty low, and I did drive up the hill of my driveway to my garage, meaning that even if on level ground there was enough fluid to prevent an airlock situation at the reservoir, the incline may have caused one, especially if the system was trying to pull fluid.
Lastly, regarding the checks I was planning to do with techstream to diagnose any ruptured damper, is that off the table for now? I wonder if given the unknown state of the system whether I could still get the info I need to make a determination. My thinking is that if I need to do a damper or the whole set, I'd rather not buy a bunch more fluid and get the system fully bled only to have to do it again when the dampers arrive. Could I just add a bottle to make sure the level in the reservoir is reasonable, then somehow figure out the damper situation, even though some air may have entered the system?
Sorry for the lengthy post. I appreciate everyone who had written on the subject in the past. Hopefully any suggestions here will add to the group, even if no one ever screws up just like this again
My new-to-me LX was low on AHC fluid. Because of this I considered a ruptured damper assembly (though the ride seemed fine), but I decided I'd go ahead and flush it and then investigate further based on results and techstream diagnostics.
My first error was due to me trying to do it from memory. After siphoning the fluid and filling the reservoir, I started the engine and raised the vehicle from low to normal before beginning the bleed. Other than flushing more fluid than necessary, I don't think this would make much difference. I mention it just in case. I added a bit more to the reservoir to make sure I didn't drop too low.
Observation: The fluid had the entrained gas (micro-bubbles) in it. I think this occurred at each bleed point on the driver side, but mostly improved by the time each bleed was complete.
I then started the engine (already in normal, mind you) and the system pressurized and raised. I then moved on to the passenger side to do the slight bleed over there. That fluid was clear except for maybe a few bigger bubbles at the beginning.
I guess I should have stopped here, but I decided to go back and do a similar slight bleed back on the driver side since I knew there had been a lot of entrapped air the first time. I started at the rear (pretty clear like I had seen on passenger side). This is where things went a bit off the rails.
I moved to the height accumulator, but nothing at all came out. I was confused and thought maybe I was having an issue with the bleeder valve. I turned it a bunch both ways and sort of lost track of how loose or tight it was, but got worried I'd back it out all the way (if that's possible).
I decided to call that off and close it up, OR SO I THOUGHT. I can't explain why, I guess since nothing ever bled from there on that attempt, but I didn't think it was open. Obviously I should have been sure it was completely closed, but I didn't. You may now guess where this is going.
I get in the truck thinking I'm done. Turn on the engine. Height adjustment begins and then acts funny, continually adjusting up and down. At this point I realize what's happening and shut off the engine. Big puddle and spray from the height accumulator. It was not closed, obviously. Clean up and close it, then add what's left in the third bottle to the reservoir which is now pretty close to the bottom. Knowing that, I turn AHC off, but at some point I guess it came on again and again lowered the level to very near the bottom of reservoir as it adjusted itself.
OK, here are my thoughts and main questions..
Besides needing to add more fluid, I'm concerned that air got in the system. Between shutting off the engine thus stopping the geyser from erupting, and closing the valve completely shortly thereafter, the height accumulate valve was open to the air. I'm not sure exactly how it works, but I assume some air could have entered. If so, will bleeding that accumulator solve the problem, or will a comprehensive bleed be required?
Similarly, the reservoir got pretty low, and I did drive up the hill of my driveway to my garage, meaning that even if on level ground there was enough fluid to prevent an airlock situation at the reservoir, the incline may have caused one, especially if the system was trying to pull fluid.
Lastly, regarding the checks I was planning to do with techstream to diagnose any ruptured damper, is that off the table for now? I wonder if given the unknown state of the system whether I could still get the info I need to make a determination. My thinking is that if I need to do a damper or the whole set, I'd rather not buy a bunch more fluid and get the system fully bled only to have to do it again when the dampers arrive. Could I just add a bottle to make sure the level in the reservoir is reasonable, then somehow figure out the damper situation, even though some air may have entered the system?
Sorry for the lengthy post. I appreciate everyone who had written on the subject in the past. Hopefully any suggestions here will add to the group, even if no one ever screws up just like this again
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