normal working status for the EAS compressor?
Thread Starter
|
4wd Low
Joined: Feb 2016
Posts: 11
Likes: 0
normal working status for the EAS compressor?
may I ask what is a normal working status for the compressor?
should it run every time car is ignited or every day to top off the reservoir (like very short 3-5 secs duration of working)?
sometimes when I turn off the engine and lock the car, I can see car lowered immediately , sometime I do not see, is it normal?
should it run every time car is ignited or every day to top off the reservoir (like very short 3-5 secs duration of working)?
sometimes when I turn off the engine and lock the car, I can see car lowered immediately , sometime I do not see, is it normal?
Rock Crawling
Joined: Jul 2019
Posts: 313
Likes: 83
From: Helsinki
Yes, both are completely normal occurrences. If the compressor runs for minutes at start you’d most likely have some kind of leak somewhere. You’d also get fault codes and a yellow suspension light eventually.
If you have an IID you can graph the values (pressures).
If you have an IID you can graph the values (pressures).
Thread Starter
|
4wd Low
Joined: Feb 2016
Posts: 11
Likes: 0
thank you for this clarification, I am much relaxed here
Camel Trophy
Joined: Nov 2017
Posts: 4,964
Likes: 950
From: Green Bay, WI
Mine rarely runs on startup after sitting. When I had a leaking front strut, that was another story. Even though at times the leak was minor it was enough for it to start every time. Really what you need to observe is if the vehicle has to raise on startup, front or rear. My guess is that yours is since there is no other reason at all for it to run. Reservoir pressure is not monitored at all, so it will never run just to fill the reservoir, it only fills it after a height adjustment. And if it is holding air, like yours is, then only a little compressor time is needed. A bit to raise a little and replenish the nearly full reservoir.
So get in and see if you observe it rising in the front, rear or both. If it does then you likely have a small leak.
So get in and see if you observe it rising in the front, rear or both. If it does then you likely have a small leak.
Thread Starter
|
4wd Low
Joined: Feb 2016
Posts: 11
Likes: 0
Mine rarely runs on startup after sitting. When I had a leaking front strut, that was another story. Even though at times the leak was minor it was enough for it to start every time. Really what you need to observe is if the vehicle has to raise on startup, front or rear. My guess is that yours is since there is no other reason at all for it to run. Reservoir pressure is not monitored at all, so it will never run just to fill the reservoir, it only fills it after a height adjustment. And if it is holding air, like yours is, then only a little compressor time is needed. A bit to raise a little and replenish the nearly full reservoir.
So get in and see if you observe it rising in the front, rear or both. If it does then you likely have a small leak.
So get in and see if you observe it rising in the front, rear or both. If it does then you likely have a small leak.
thanks, I am doing a third height measurement today overnight ( Off-road height, door open, ignition off, fuse 3 and 26 pulled)
I did second one with about one week ago ( Off-road height, door open, ignition off) found no height drop overnight
My first one ( Off-road height, door open, ignition off, fuse 3 and 26 pulled) was done before the replacement of the front valve block , and I DID find both front height dropped overnight while NOT rear ones
Camel Trophy
Joined: Nov 2017
Posts: 4,964
Likes: 950
From: Green Bay, WI
Off-road height is silly. I don't know how or why that started as a recommendation. I mean it can be okay for the overall diagnosis but only as a secondary test. The truck is normally at standard height so that is where the first leak test should be done. And no need to leave the door open if the fuse is pulled, you only need to pull 26 which is for the EAS computer. I actually pull this fuse all the time when camping because after I level the truck with the GAP tool I want it to stay level. I really need to install a switch or maybe get an X-Lifer....
Going back to heights.... so the reason you should test at standard has to do with the struts themselves. They have rubber bladders, sorta, and they have a fold. This is all hidden by the aluminum shell. But where the fold is located on the bladder is relative to height and the fold is where the most stress is on the rubber bladder. And since the vehicle is normally at standard height for most of its life then that fold is generally along one area of the rubber therefore that area is where the most cracks will form over time. The kicker is that with cracks in rubber like this is when the fold changed location those cracks can sorta seal up and may not leak at all, not even a little. So as part of a leak test and to be sure the struts are not leaking at the rubber bladders then you should keep it at standard height, at least for the initial test. With that said, the struts can leak in a couple other spots too, mainly at the very top due to internal o-rings failing. But cracks in the airbags are super common.
As for valve blocks. A couple things to know, they are front and rear specific. I always mention this because some sellers say they are for either when they are not - they do look identical. Second, valve block leaks are very, very often cause by desiccant material from the compressor contaminating the o-rings. This is why rebuilding them works well, new rings and all clean inside again. But if you do not rebuild the compressor dryer then the issue will quickly return. The best ting to do is service the compressor or replace it. Then wait a couple weeks for the desiccant powdery bits to work out of the system. Then one finally services or replaces the valve blocks.
Lastly, and you prob know, but a drop in front can be cause by just one strut. That engine is heavy so it may look like both sides drop but it could easily just be one bag that lost air and the other is simply taking the weight and thus it will also drop.
Going back to heights.... so the reason you should test at standard has to do with the struts themselves. They have rubber bladders, sorta, and they have a fold. This is all hidden by the aluminum shell. But where the fold is located on the bladder is relative to height and the fold is where the most stress is on the rubber bladder. And since the vehicle is normally at standard height for most of its life then that fold is generally along one area of the rubber therefore that area is where the most cracks will form over time. The kicker is that with cracks in rubber like this is when the fold changed location those cracks can sorta seal up and may not leak at all, not even a little. So as part of a leak test and to be sure the struts are not leaking at the rubber bladders then you should keep it at standard height, at least for the initial test. With that said, the struts can leak in a couple other spots too, mainly at the very top due to internal o-rings failing. But cracks in the airbags are super common.
As for valve blocks. A couple things to know, they are front and rear specific. I always mention this because some sellers say they are for either when they are not - they do look identical. Second, valve block leaks are very, very often cause by desiccant material from the compressor contaminating the o-rings. This is why rebuilding them works well, new rings and all clean inside again. But if you do not rebuild the compressor dryer then the issue will quickly return. The best ting to do is service the compressor or replace it. Then wait a couple weeks for the desiccant powdery bits to work out of the system. Then one finally services or replaces the valve blocks.
Lastly, and you prob know, but a drop in front can be cause by just one strut. That engine is heavy so it may look like both sides drop but it could easily just be one bag that lost air and the other is simply taking the weight and thus it will also drop.
Thread Starter
|
4wd Low
Joined: Feb 2016
Posts: 11
Likes: 0
Off-road height is silly. I don't know how or why that started as a recommendation. I mean it can be okay for the overall diagnosis but only as a secondary test. The truck is normally at standard height so that is where the first leak test should be done. And no need to leave the door open if the fuse is pulled, you only need to pull 26 which is for the EAS computer. I actually pull this fuse all the time when camping because after I level the truck with the GAP tool I want it to stay level. I really need to install a switch or maybe get an X-Lifer....
Going back to heights.... so the reason you should test at standard has to do with the struts themselves. They have rubber bladders, sorta, and they have a fold. This is all hidden by the aluminum shell. But where the fold is located on the bladder is relative to height and the fold is where the most stress is on the rubber bladder. And since the vehicle is normally at standard height for most of its life then that fold is generally along one area of the rubber therefore that area is where the most cracks will form over time. The kicker is that with cracks in rubber like this is when the fold changed location those cracks can sorta seal up and may not leak at all, not even a little. So as part of a leak test and to be sure the struts are not leaking at the rubber bladders then you should keep it at standard height, at least for the initial test. With that said, the struts can leak in a couple other spots too, mainly at the very top due to internal o-rings failing. But cracks in the airbags are super common.
As for valve blocks. A couple things to know, they are front and rear specific. I always mention this because some sellers say they are for either when they are not - they do look identical. Second, valve block leaks are very, very often cause by desiccant material from the compressor contaminating the o-rings. This is why rebuilding them works well, new rings and all clean inside again. But if you do not rebuild the compressor dryer then the issue will quickly return. The best ting to do is service the compressor or replace it. Then wait a couple weeks for the desiccant powdery bits to work out of the system. Then one finally services or replaces the valve blocks.
Lastly, and you prob know, but a drop in front can be cause by just one strut. That engine is heavy so it may look like both sides drop but it could easily just be one bag that lost air and the other is simply taking the weight and thus it will also drop.
Going back to heights.... so the reason you should test at standard has to do with the struts themselves. They have rubber bladders, sorta, and they have a fold. This is all hidden by the aluminum shell. But where the fold is located on the bladder is relative to height and the fold is where the most stress is on the rubber bladder. And since the vehicle is normally at standard height for most of its life then that fold is generally along one area of the rubber therefore that area is where the most cracks will form over time. The kicker is that with cracks in rubber like this is when the fold changed location those cracks can sorta seal up and may not leak at all, not even a little. So as part of a leak test and to be sure the struts are not leaking at the rubber bladders then you should keep it at standard height, at least for the initial test. With that said, the struts can leak in a couple other spots too, mainly at the very top due to internal o-rings failing. But cracks in the airbags are super common.
As for valve blocks. A couple things to know, they are front and rear specific. I always mention this because some sellers say they are for either when they are not - they do look identical. Second, valve block leaks are very, very often cause by desiccant material from the compressor contaminating the o-rings. This is why rebuilding them works well, new rings and all clean inside again. But if you do not rebuild the compressor dryer then the issue will quickly return. The best ting to do is service the compressor or replace it. Then wait a couple weeks for the desiccant powdery bits to work out of the system. Then one finally services or replaces the valve blocks.
Lastly, and you prob know, but a drop in front can be cause by just one strut. That engine is heavy so it may look like both sides drop but it could easily just be one bag that lost air and the other is simply taking the weight and thus it will also drop.
thanks, Duly noted
I changed the front valve block, and after the replacement, I took height measurement TWICE, first NO CHANGE, second the Left Front has 1/16 inch difference (it could be my own tolerance issue), but I will take a third just for the Left Front in your way (normal height, ignition off when door open, Fuse 26 pull and door shut)
I have taken apart the valve block preliminarily (the solenoid untouched yet), I found NO white powder/residue stuff, but I will rebuild it anyway as a backup parts
Thread Starter
|
4wd Low
Joined: Feb 2016
Posts: 11
Likes: 0
Off-road height is silly. I don't know how or why that started as a recommendation. I mean it can be okay for the overall diagnosis but only as a secondary test. The truck is normally at standard height so that is where the first leak test should be done. And no need to leave the door open if the fuse is pulled, you only need to pull 26 which is for the EAS computer. I actually pull this fuse all the time when camping because after I level the truck with the GAP tool I want it to stay level. I really need to install a switch or maybe get an X-Lifer....
Going back to heights.... so the reason you should test at standard has to do with the struts themselves. They have rubber bladders, sorta, and they have a fold. This is all hidden by the aluminum shell. But where the fold is located on the bladder is relative to height and the fold is where the most stress is on the rubber bladder. And since the vehicle is normally at standard height for most of its life then that fold is generally along one area of the rubber therefore that area is where the most cracks will form over time. The kicker is that with cracks in rubber like this is when the fold changed location those cracks can sorta seal up and may not leak at all, not even a little. So as part of a leak test and to be sure the struts are not leaking at the rubber bladders then you should keep it at standard height, at least for the initial test. With that said, the struts can leak in a couple other spots too, mainly at the very top due to internal o-rings failing. But cracks in the airbags are super common.
As for valve blocks. A couple things to know, they are front and rear specific. I always mention this because some sellers say they are for either when they are not - they do look identical. Second, valve block leaks are very, very often cause by desiccant material from the compressor contaminating the o-rings. This is why rebuilding them works well, new rings and all clean inside again. But if you do not rebuild the compressor dryer then the issue will quickly return. The best ting to do is service the compressor or replace it. Then wait a couple weeks for the desiccant powdery bits to work out of the system. Then one finally services or replaces the valve blocks.
Lastly, and you prob know, but a drop in front can be cause by just one strut. That engine is heavy so it may look like both sides drop but it could easily just be one bag that lost air and the other is simply taking the weight and thus it will also drop.
Going back to heights.... so the reason you should test at standard has to do with the struts themselves. They have rubber bladders, sorta, and they have a fold. This is all hidden by the aluminum shell. But where the fold is located on the bladder is relative to height and the fold is where the most stress is on the rubber bladder. And since the vehicle is normally at standard height for most of its life then that fold is generally along one area of the rubber therefore that area is where the most cracks will form over time. The kicker is that with cracks in rubber like this is when the fold changed location those cracks can sorta seal up and may not leak at all, not even a little. So as part of a leak test and to be sure the struts are not leaking at the rubber bladders then you should keep it at standard height, at least for the initial test. With that said, the struts can leak in a couple other spots too, mainly at the very top due to internal o-rings failing. But cracks in the airbags are super common.
As for valve blocks. A couple things to know, they are front and rear specific. I always mention this because some sellers say they are for either when they are not - they do look identical. Second, valve block leaks are very, very often cause by desiccant material from the compressor contaminating the o-rings. This is why rebuilding them works well, new rings and all clean inside again. But if you do not rebuild the compressor dryer then the issue will quickly return. The best ting to do is service the compressor or replace it. Then wait a couple weeks for the desiccant powdery bits to work out of the system. Then one finally services or replaces the valve blocks.
Lastly, and you prob know, but a drop in front can be cause by just one strut. That engine is heavy so it may look like both sides drop but it could easily just be one bag that lost air and the other is simply taking the weight and thus it will also drop.
sorry to bother you again
I took the height measurement with normal height, and ALL 4 corner drops, it is completely different result than what I took before with Off-Road height
I will do again tonight with Off-Road height
I am thinking to get a IID tool, can you help me what I should do with IID to pin-point the actual issue?
Camel Trophy
Joined: Nov 2017
Posts: 4,964
Likes: 950
From: Green Bay, WI
And you had the fuse out? Just want to verify. I say this because of how the system self levels once the truck is off. I think it is at two hours and then every six hours where the truck will lower where needed to make the vehicle as level as practical. It can not use the reservoir or compressor during those adjustments. So if there is a leak in front, it will drop the read to match for example.
Also keep in mind that some lowering can be normal. If the vehicle was parked after being driven its possible the air in the struts is on the warmer side. Then overnight as the air cools in the struts and contracts you can get a little lowering. But not much at all.
How much did all four corners drop? And the GAP tool is nice, it can not give all the answers but it can help for sure.
Also keep in mind that some lowering can be normal. If the vehicle was parked after being driven its possible the air in the struts is on the warmer side. Then overnight as the air cools in the struts and contracts you can get a little lowering. But not much at all.
How much did all four corners drop? And the GAP tool is nice, it can not give all the answers but it can help for sure.
Thread Starter
|
4wd Low
Joined: Feb 2016
Posts: 11
Likes: 0
And you had the fuse out? Just want to verify. I say this because of how the system self levels once the truck is off. I think it is at two hours and then every six hours where the truck will lower where needed to make the vehicle as level as practical. It can not use the reservoir or compressor during those adjustments. So if there is a leak in front, it will drop the read to match for example.
Also keep in mind that some lowering can be normal. If the vehicle was parked after being driven its possible the air in the struts is on the warmer side. Then overnight as the air cools in the struts and contracts you can get a little lowering. But not much at all.
How much did all four corners drop? And the GAP tool is nice, it can not give all the answers but it can help for sure.
Also keep in mind that some lowering can be normal. If the vehicle was parked after being driven its possible the air in the struts is on the warmer side. Then overnight as the air cools in the struts and contracts you can get a little lowering. But not much at all.
How much did all four corners drop? And the GAP tool is nice, it can not give all the answers but it can help for sure.
I would appreciate if you can let me know what reading I should monitor from GAP tool since you have deep knowledge on this from your leaking issue. Thanks
here is my measurement result
1. with normal height, after Front Valve Block replaced, Second person helped with measurement, 24 Hours
Left Front 32.75 32.375
Left Rear33.375 33.315
Right Front 33.125 32.75
Right Rear 33.75 33.50
2. with off-road height, after Front Valve Block replaced, Second person helped with measurement, 20 Hours
Left Front 35.5 35.25
Left Rear 36.06 35.75
Right Front 35.25 35.125
Right Rear 35.75 35.625
3. with off-road height, BEFORE Front Valve Block replaced, 12 Hours
Left Front 34.875 34.75
Left Rear35.5 35.5
Right Front 35 34.875
Right Rear 35.5 35.5
4. with off-road height, BEFORE Front Valve Block replaced, 12 Hours
Left Front 34.5 34.25
Left Rear35.20 35.15
Right Front 34.5 34.25
Right Rear 35 35
Last edited by jackkyxu; Apr 20, 2025 at 04:43 PM.