Went to RV yesterday and found air system completely down. Located a leak in the 120V compressor compartment on a small silver/black component on the sidewall. It is about 2 inches long by 1 inch wide, mounted to the sidewall near the compressor with two plug on electrical connections and an air supply from the compressor exhaust(?) side. The air supply runs through another component before reaching the part leaking. There is a full-blown air leak from the bottom of this small component which has drained the entire system.
I have tried to post pictures but obviously need some guidance on how to post.
Thanks!!
This is another picture with the part in question outlined by the crude blue box.
Thank you.
That is a 120V operated air solenoid valve. It’s purpose is to relieve pressure when the air compressor is NOT running so that the air comp does not start against a head pressure.
https://www.mcmaster.com/solenoid-valves...valves-10/
Not the cheapest place, but they usually have what I want. Look at the 120V versions. You may have to do a little plumbing fit up.
Thank you Richard. The compressor was running when I got there so I guess it is stuck open. Thanks again.
Chris
My thoughts may be off base as my system is plumbed a bit differently, but here goes.
That solenoid valve may well be a normally open valve. In other words, when no power is applied it is open. The purpose, as Richard has already mentioned, is to relieve the pressure after the compressor stops so when it is requested to start again, it is not starting against 70 psi or so. For this to work, that solenoid valve is normally located between the compressor and a check valve. The check valve keeps the entire air system from draining back through the normally open check valve when the compressor is off. I think your symptoms may well be consistent with a failed check valve and there the possibility that the solenoid valve is not the issue.
Yeah, that is definitely a after factory setup. Nothing wrong with it, it’s just different. It appears the check valve in the system is just after the air dryer/particulate filter.
I actually think the setup is quite clever with the check valve AFTER the drier, because as some of us know the drier bowl cracks and usually is a big leak source. It’s not if the bowl cracks, it’s when. This way a cracked bowl isn’t a huge problem. The owner has to manually drain the bowl, no big deal.
Good catch @"RussWhite" on the a failed check valve also giving the same symptoms.
I had that solenoid fail in exactly the same manner. It was before the dryer in my coach and when it froze…it broke. Newell’s price is approximately one arm + one leg. (I searched online for that exact part and came up empty). I ended up buying from Newell.
Richard suggestion is a good one. An off the shelf solenoid is the answer.
Bill
712 a 04 has a check valve after the filter dryer and a normally closed solenoid valve wired in parallel with the compressor that opens when the compressor turns on
Searching for air leaks landed me on this thread.
I wonder - did you guys all experienced air leaks in the past with your Newell coach?
I recently purchased the 2004 #701 and I suspect a possible air leak somewhere. The symptom is the coach's rear appears low when riding.
I haven't picked up this coach yet. I just want to prepare as many spare parts tools as possible for a quick fix. Because I called several RV repair shops in Fort Worth TX (the location where this coach is currently at) one shop says they have over 2 months of backlog, and another shop I just get voicemail no call-back yet.
The sad truth is leaks are a inevitable issue. You could do what many members here have done and replace all the push on fittings with DOT compression fitting..that will help and since you are there will find it easier to locate leaks. I know of not coach that has NO leaks. Best i have read was 2 short 120v compressor runs each 24 hour period from a member on here. that's spectacular results!
As long as your braking systems hold air and it's a slow leak.. take your time to track it down. If it's affecting your systems like toilets and the like and you can't live with it... slowly find each one and solve.
YMMV
The rear sitting low is not a common air leak issue. Potential causes: the rear ride height control levers are out of adjustment (one on each side), a leak in one or both air bags (you don't say if it is sitting low on both sides), a leak at the rear six pack, or the tag axle is not getting enough air to assist in supporting the rear. Newells don't have a bunch of clearance. If someone raised the front too high, it would make it look like the rear is sitting low also. I believe 701 has the HWH suspension. if so, measure the distance from the ground to the 1" square tubing that runs along the inside of the lower body. They should be the same at the rear of the front wheel well, the front of the right drive wheel well and the front of the left drive wheel well. They should be in the 11-12" range.