I've got a leak.

OK, that's no surprise since I've had the struts on and off several times recently. It's the left front (driver) and it's leaking pretty darn fast. Shut the truck down and leave it in 'build mode' (or pull the fuses) and I can watch the live values on that corner drop by around a mm per minute.

I assumed I had a leak at the air line fittings going into that corner but couldn't see any bubbles when I did the soapy water test. I even replaced the fitting w/a new one. No change.

I'm actually wondering if the strut itself could be leaking internally at this point. It's a 1-year old Arrnott strut.

Anybody else had an internal strut leak? The only other possibility I can think of is if by some random chance the front valve block started leaking. But since I haven't messed with it that would be quite the coincidence.

 

I would think that since the live value shows a pressure decrement in that corner, it would be related to the strut and not the valve block...but I have little experience in these matters. I've never even touched the valve blocks!

 

I can't actually monitor the pressures, only the height. That corner is dropping pretty fast.

I bought 2 front Arrnott struts from Shockwarehouse 11/25 last year. I had one snap at the lower mounting eye a couple months ago and I've been waiting on the warranty (1 year) replacement ever since. Currently they say they expect to receive more in on 12/10 and will ship me a new one then (from FL, so a week shipping). Now that I'm just out of warranty it looks like the other one has failed. I pinged shockwarehouse's customer service today to let them know - if they're good they'll offer to replace it since it's so close to warranty and I've already had issues with them/Arrnott, but technically they're not obligated to do so since I am out of warranty.

I suppose I could swap struts side to side, but that's a bit of a PITA just to confirm what I'm pretty sure of anyway. And with my luck I'd introduce a leak on the other one!

 

That's a total drag...

 

Try checking the fittings around the valve block, especially since the front is easier to get to (not sure if the ARB changes how easy access is). My rear lines had a tiny hole at the fitting on the rear block so it always seemed like it was the strut that was leaking. Pinhole leak at the right side fitting (for example). If that's the case super easy swap.

 

I need to replace a burned out bulb in the front left corner marker anyway, so I'll check the valve block, but it would have to be quite the coincidence that the block would suddenly start leaking when I was working on the strut. Nothing to loose, so I'll check it but my gut says no that won't be it.

 

It has been suggested before that the lines can get perforated by the desiccant material (from the air dryer) that becomes powder and gets into the air lines. Might just be a coincidence but hope you find the issue regardless.

 

I gave the front air block a good soaking in soapy water and didn't find any bubbles. If they were cheaper I'd change it anyway just because it's of unknown age, but I hate to just throw $175 parts at things for the hell of it.

I wouldn't expect a line to have a hole; that would seem to be an all or nothing sort of thing.

If I get around to it I may try running a temporary line from the valve block around to the strut. I've got extra lines/fittings on-hand I could try it with. But for the moment I've moved on to other chores.

Oddly, it doesn't seem to be sinking as fast today. I have no explanation for this.

 

Well keep in mind temperature is a huge factor with these things. I've known for a couple seasons now that I've got a leak, but as long as I get through winter the summer is a breeze (no pun intended..) but yeah.

Think space shuttle Challenger SRB failure due to the o-rings and temperature.

Anyways you're probably aware of the cold weather thing already, but I was faced with a few "what the hell" moments initially as well, and it was always temperature related. Although mine was most of the vehicle (at least the front) so I'm probably looking at a valve block leakage issue.

Same with alternator whine/stress, a creaky interior, a sometimes-PITA starter solenoid, etc.

edit: at the end of the day it doesn't matter if it's "internal" or not, you SHOULD be able to see the leak with soapy water, as at some point that air has to escape the air spring outer bladder/assy/seals on top/bottom which would generate bubbles.

I've seen failures of push-lock DOT fittings many times with trucks and hot-rods alike, once the nylon tube gives way to the teeth that lock the tube in place over many years and heat cycles, they start to leak. IF you ever release a push-lock tube to replace or re-fit a fitting, you must cut the first 1/8" of tube off, preferable with a tube blade cutter or a razor blade so you don't crimp it and it stays perfectly circular. I've released old tube where you can visually see a smaller diameter at the end due to age.

 

Despite no bubbles I have one fitting that I suspect more than anything else. I actually replaced it with a better quality metal fitting, but the problem is that there is a 90* bend in the line very close to the end so it stresses the joint. Unfortunately I can't just cut back past the bend since that would simply make the other end of the junction the bend.

I don't have any more time to mess with it since I'm leaving on a run this weekend and still have several more important things to sort out like a drive shaft and CV shaft, but when I get some time and energy I'll probably pull a temporary line from the valve block around to the strut and see what happens. That way I'll eliminate that joint as well as the whole line as candidates. If it still drops it has to be the valve block or internal to the strut. I have another strut due later this month so I can put it on to test (it's supposed to go on the passenger side). That would only leave the valve block, which costs a few bucks but at least is easy to change.