Air Pressure down to 2psi overnight

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Air Pressure down to 2psi overnight

November 16, 2020, 07:27:28 am

I have a new to me 2009 Nimbus and my front and rear air pressure readings go down to 2 psi overnight. This is my 2nd DP and didn't experience this in my Country Coach, is this normal for Foretravel or do I have a leak? The coach stays level so it does not appear to be the air bags. any guidance would be appreciated.

Re: Air Pressure down to 2psi overnight

Reply #1 – November 16, 2020, 07:33:06 am

You sure have several leaks dropping that fast or one big leak. It could be leaking out a fitting or a bad spot on a hose. These can be found with kids bubbles that have been put in a spray bottle. If this is a dead end then you have an internal leak through your protection valves (these should close at about #60) and the check valves at your storage tanks and the check valve in your air dryer.

Overnight we may loose #10 total overnight not down to #10.

Mike

Re: Air Pressure down to 2psi overnight

Reply #2 – November 16, 2020, 08:28:28 am

Also make sure your auxiliary air compressor is working.

Re: Air Pressure down to 2psi overnight

Reply #3 – November 16, 2020, 08:36:08 am

Do you know when the air dryer was last serviced?

Re: Air Pressure down to 2psi overnight

Reply #4 – November 16, 2020, 08:38:47 am

Quote from: Chuck & Jeannie – November 16, 2020, 08:36:08 am

Do you know when the air dryer was last serviced?

No I don't, and thank you for the feedback. Any recommendations for a service center in the Phoenix Arizona area?

Re: Air Pressure down to 2psi overnight

Reply #5 – November 16, 2020, 08:39:45 am

Quote from: folivier – November 16, 2020, 08:28:28 am

Also make sure your auxiliary air compressor is working.

I believe it is as it goes on frequently.

Re: Air Pressure down to 2psi overnight

Reply #6 – November 16, 2020, 08:44:03 am

If it is cycling often this could be the tie in valve to your main air system leaking or you could have a leak in a 6 pack, air bag or related piping or your slide seal system. This little compressor isn't there to keep the main air system full.

Mike

Re: Air Pressure down to 2psi overnight

Reply #7 – November 16, 2020, 08:44:23 am

As noted by Mike (above), both of your protection valves (and possibly other valves) are leaking. They should maintain pressure in your F & R brake tanks at about 60 psi for at least a day or two. This is not a good sign, because the protection valves are "down stream" quite a ways from the air compressor. It is possible the valves are contaminated with white powder from a failed air compressor cartridge.

Re: Air Pressure down to 2psi overnight

Reply #8 – November 16, 2020, 08:44:29 am

Your air leaks are working your Aux pump a bunch. My pump runs once or twice per day.

I fixed leaks in the air bladder systems and isolated the Aux pump from the level system as my coach sits level with out help from the HWH level system pad.

My air guages on the dash sit at zero all the time after sitting for several days. Aux air pressure is 90 psi and bladder supply pressure is 12 psi.

Re: Air Pressure down to 2psi overnight

Reply #9 – November 16, 2020, 08:48:22 am

When the air system is pressured up, and you open the water drain valve on the wet tank, what comes out?

Re: Air Pressure down to 2psi overnight

Reply #10 – November 16, 2020, 08:57:03 am

It sounds like I have 2 problems then.

1) The check valves are not working on my brake tanks
2) There may be a leak in the air bag or slide seal system.

Does anyone have a recommended service facility in Phoenix?

Re: Air Pressure down to 2psi overnight

Reply #11 – November 16, 2020, 09:00:45 am

When the air system is pressured up, and you open the water drain valve on the wet tank, what comes out?

Re: Air Pressure down to 2psi overnight

Reply #12 – November 16, 2020, 09:03:29 am

I will suggest you have a bladder seal leak and nothing else.

Re: Air Pressure down to 2psi overnight

Reply #13 – November 16, 2020, 09:05:29 am

Using the Forum search tool, I found the following recommendation:

Great Service in Phoenix, AZ - Massey's Diesel and RV Repair

FOT has, on their website, a downloadable list of owner recommended service shops. There are 2 shops in Arizona:

FORETRAVEL

Re: Air Pressure down to 2psi overnight

Reply #14 – November 16, 2020, 09:15:51 am

Our speculating on possible leak sources (all real potential areas) may not be leading you to the source.

Absolutely, check for what comes out the tank drains and let us know.

Then, WITH COACH PROPERLY SUPPORTED and air pressure up, check everything with a soap solution.

Re: Air Pressure down to 2psi overnight

Reply #15 – November 16, 2020, 09:28:58 am

jimgior13 has asked about a service center twice. They may be challanged to work on the system (knowledge or ability). We all assume that people do as we do.

jimgior13

Contact info for Phoenix
East Valley RV Specialist, 10020 E. Apache Trail, 866-846-7726, www.eastvalleyrv.com
Little Dealer Little Prices. 2350 W. Deer Valley, 623-889-3900, Little Dealer Little Prices | Arizona RV Dealer | Top 50 RV Dealer | Best RV...

Re: Air Pressure down to 2psi overnight

Reply #16 – November 16, 2020, 10:32:34 am

Quote from: Chuck & Jeannie – November 16, 2020, 09:00:45 am

When the air system is pressured up, and you open the water drain valve on the wet tank, what comes out?

Excuse my ignorance, but which wet tank?

Re: Air Pressure down to 2psi overnight

Reply #17 – November 16, 2020, 10:41:46 am

Quote from: jimgior13 – November 16, 2020, 10:32:34 am

Excuse my ignorance, but which wet tank?

You are not ignorant. You are following the exact same learning curve that we all go through. It seems daunting at first, but you will soon get up to speed. Continue hanging out here, read the posts, listen to the comments...before long you will be answering questions instead of asking them.

Do you have a air system diagram for your coach? If so, look at it. Follow the path of compressed air after it leaves the engine air compressor. It will go the the air dryer, where moisture and oil are removed, and then to the first air tank in the system. This is the "wet tank", so named because it serves as a backup trap for water that gets past the air dryer.

Ideally, the dryer will remove all the water, and the wet tank will only receive dry air. If, for any reason, the dryer is not doing it's job then water will accumulate in the wet tank. You should on a regular basis open the tank drain valve to check. If you only get dry air - that's good. If you get any water, or oily looking wet whitish paste, then that is a sign of possible dryer failure. In that case, the dryer should be serviced ASAP.

The wet tank drain valve is probably located in the driver side rear wheel well, in front of the outside dual tire.

Re: Air Pressure down to 2psi overnight

Reply #18 – November 16, 2020, 10:43:23 am

Quote from: Chuck & Jeannie – November 16, 2020, 10:41:46 am

You are not ignorant. You are following the exact same learning curve that we all go through. It seems daunting at first, but you will soon get up to speed. Continue hanging out here, read the posts, listen to the comments...before long you will be answering questions instead of asking them.

Do you have a air system diagram for your coach? If so, look at it. Follow the path of compressed air after it leaves the engine air compressor. It will go the the air dryer, where moisture and oil are removed, and then to the first air tank in the system. This is the "wet tank". It is so named because it serves as a backup trap for water the gets past the air dryer.

Thank you I'll go look for that now and post the results.

Re: Air Pressure down to 2psi overnight

Reply #19 – November 16, 2020, 11:13:07 am

Quote from: jimgior13 – November 16, 2020, 10:43:23 am

Thank you I'll go look for that now and post the results.

It's also possible to pay a good mechanic, one who is used to working with air brakes, to localize the leaks, mark and note their location, and present you with some options. Someone used to working on heavy machinery will have not only the safety equipment but a flexible back and good hearing. Think truck repair shop.

And to second what Chuck and Jeannie said earlier, it's a steep learning curve but it ain't rocket science. I am also a firm believer that anyone operating a heavy truck needs at least an overview on the workings of the braking system when they lay their foot on the treadle. This was my first area of study after our new-to-me Foretravel arrived.

Re: Air Pressure down to 2psi overnight

Reply #20 – November 16, 2020, 11:29:01 am

Chuck,

Thank you for this clear concise description (Reply #17). It was a couple of years of ownership before I fully understood my air system.

Richard

Re: Air Pressure down to 2psi overnight

Reply #21 – November 16, 2020, 11:48:51 am

Quote from: Old Toolmaker – November 16, 2020, 11:13:07 am

It's also possible to pay a good mechanic, one who is used to working with air brakes, to localize the leaks, mark and note their location, and present you with some options. Someone used to working on heavy machinery will have not only the safety equipment but a flexible back and good hearing. Think truck repair shop.

And to second what Chuck and Jeannie said earlier, it's a steep learning curve but it ain't rocket science. I am also a firm believer that anyone operating a heavy truck needs at least an overview on the workings of the braking system when they lay their foot on the treadle. This was my first area of study after our new-to-me Foretravel arrived.

Here in Canada to be able to get a license to drive a vehicle with air brakes you have to go thru an Air Brake course then sit an exam for a license. Driving without this license is against the law.
Johnh

Re: Air Pressure down to 2psi overnight

Reply #22 – November 16, 2020, 12:21:22 pm

I had Massey's in Phoenix ,April 2019 replace my original shocks with 8 koni far shocks. Plus replaced the green coolant with red fleetguard
Complete coolant.
Service mgr Tom is good. As mentioned, it's a very busy semi shop, but they had several coaches there.
Usually booked in advance, so call to explain your problem. Good luck

Re: Air Pressure down to 2psi overnight

Reply #23 – November 16, 2020, 02:42:01 pm

Quote from: folivier – November 16, 2020, 08:28:28 am

Also make sure your auxiliary air compressor is working.

the pressure switch on my aux compressor had a pinhole leak in the diaphragm and would leak the system and have to cycle on every 20mins to keep up...new switch fixed it up..

Re: Air Pressure down to 2psi overnight

Reply #24 – November 16, 2020, 03:37:04 pm

Here are my findings so far.

I ran the engine and built up the pressure, shut down and went to the engine compartment. I could definitely hear a air leak coming from the right side as you look into the engine compartment. I sprayed soapy water but was unable to find an exact location, but there is a definite leak. Within minutes both front and back air tanks bled down significantly. While the engine is running air pressure is around 118 both front and rear - is this safe enough to drive with the leak?

I was unable to locate the wet tank for the air system - would it be close to the engine or in one of the basements?

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