So before the valve block as replaced there was no issue. Why did you replace it? I guess I have to assume you used an aftermarket valve block, which are known to be an issue and leak, or there is a small leak at the block. There is no value to really look at with the GAP tool in this case because it will not trigger a fault.

 

before replacement, I saw frequent compressor run and running long time, and I saw there is a drop in front height, while NOT in rear

I use ORIGINAL NEW front valve block.

After the replacement, compressor run MAY not be as frequent as before (it is my personal feeling) and running time reduced (usually in less than 10 secs, occasionally going beyond 30 seconds)

I SAW somewhere that people use GAP tool to monitor the PSI change in the EAS system (strut, reservoir, valve ....) to pin-point the issue. That is why I ask

 

The GAP tool can only measure gallery pressure. That is the pipe network from the compressor to the front and rear air blocks. Reading it does not really help in your case since your compressor works fine. And the gallery pressure is designed to bleed off and can even reach zero which is a non-issue. In fact the compressor "fart" you may hear before and after compressor operation is to bleed off gallery pressure. There is no way to monitor individual struts pressures, that sure would be handy tho.

So I think at this point your best bet is to start hunting for leaks with soapy water. First at the valve blocks then the struts, including the very top. The bladder itself is pretty hard to check since its a bit hidden and the rears are behind a boot.

 

do you think the air pipe could be also the issue from my measurement results above?

 

The only way struts themselves can leak is with an internal leak at the seals, bladder leak or yes the line that connects the strut to the valve block. Or an internal leak of the valve block.

Soapy water test is the best way to check for leaks at this point.

Another option would maybe be to install 6mm shut off valves on each line to each strut. Then you can isolate the struts 100% from the system. If it drops then you know for sure the leak is from that valve to anywhere to and including the strut. You may even be able to ID which side better. I am just not a huge fan of adding potential failure points to a system.

 

thanks for such info

 

I am asking for your opinion, I am in condo and do not have much spare space for car maintenance, since I do have any fault code thrown out, do you think I can wait for the leaking to get worse ? my thinking: the leaking is really slow now (do you think so? ) may not easy to find with soap water

thanks

 

I would do the test. It is not difficult to do but for starters, just do the struts. That way you have to remove nothing at all. Go ahead and set off-road height. Then look onto the strut for the air line connection AND the center rubber bushings. Spray all that and with a very bright light try to see anything. If the internal strut seals have started to leak, you will see bubbles around that rubber center bit. A phone can help make for a set of eyes up there. If you do this you can at least diagnose that and maybe rule them out.

If all good, your next move is the front valve block. People often get leaks at the connections, especially after working on them. Some have split the plastic a bit by over tightening the lines to the block. So later one, when you have time check that. You do not have to remove the entire wheel well liner, you can remove the plastic fender flare, remove some of the plastic rivets and aggressively fold the liner up with the front of the wheel turned outwards. I have done this to access the front block a few times, quicker and less work and just enough space to look at it.

Or yes, wait til it gets worse. It may not tho! If it does not, then it may be a leak at a line fitting. If it does get worse, then probably a strut(s) or contamination of the valve block.

 

Really the only harm is the excess wear on the compressor over the long run and your leak is not enough at this time to make me worry about that much. If it dropped low, like to access height, every night then you will in fact really wear it out. But your drop is very little.