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Topic: Air Pressure down to 2psi overnight (Read 2085 times) previous topic - next topic

Re: Air Pressure down to 2psi overnight

Reply #20 –
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 –
Quote from: Old Toolmaker –
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 –
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 –
Quote from: folivier –
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 –
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?



Re: Air Pressure down to 2psi overnight

Reply #25 –
If you mean to drive to a shop, yes but I would get it fixed right away. You Probably need to get under the coach but unless you
have suspension blocks don't go under. Did you open the engine battery door to find the leak.

Re: Air Pressure down to 2psi overnight

Reply #26 –
Quote from: jimgior13 –
1. I could definitely hear a air leak coming from the right side as you look into the engine compartment.
2. While the engine is running air pressure is around 118 both front and rear - is this safe enough to drive with the leak?
3. 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?

1.On some of the Nimbus coaches they hid the air dryer on that side up behind the tag axle. It could be the purge valve has broken or has trash in it not letting it close. Or it could be a bad hose in that area.
2. Should be unless it gets worse.. How long has this been going on? 
3. The drain should be just in front of the left hand (drivers side) duel wheel hid under the fender skirt down real low. The tank its self is hid above the differential.

Mike

Re: Air Pressure down to 2psi overnight

Reply #27 –
Quote from: Pamela & Mike –
1.On some of the Nimbus coaches they hid the air dryer on that side up behind the tag axle. It could be the purge valve has broken or has trash in it not letting it close. Or it could be a bad hose in that area.
2. Should be unless it gets worse.. How long has this been going on? 
3. The drain should be just in front of the left hand (drivers side) duel wheel hid under the fender skirt down real low. The tank its self is hid above the differential.

Mike
Thanks Mike - back to the coach to look for the drain.  I've only had the coach a month and noticed 2 weeks ago.

Re: Air Pressure down to 2psi overnight

Reply #28 –
Quote from: jimgior13 –
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?

My wet tank bleed is in front of the drivers side drive wheel in the front of the wheel well.


Keith

Re: Air Pressure down to 2psi overnight

Reply #29 –
Quote from: oldguy –
If you mean to drive to a shop, yes but I would get it fixed right away. You Probably need to get under the coach but unless you
have suspension blocks don't go under. Did you open the engine battery door to find the leak.
Not the engine battery door but the rear engine access. 

Re: Air Pressure down to 2psi overnight

Reply #31 –
That thing with the round black cap is your D2 governor.  If the air is coming out the exhaust port then the governor may be/is bad. They are about $25 If the governor was telling the compressor to pump and never shut down then the over pressure valve would be sounding off on the wet tank.

Mike

On edit: That (a governor) is one thing you need to have as a spare that travels with you all the time along with the end wrench that it takes to change it out. If you aren't mechanical inclined  find someone that will show you how to change it out as that is the heart of your air system. It isn't but 2 bolts and hose but important for you to be able to DIY

Re: Air Pressure down to 2psi overnight

Reply #32 –
Quote from: Pamela & Mike –
That thing with the round black cap is your D2 governor.  If the air is coming out the exhaust port then the governor may be/is bad. They are about $25 If the governor was telling the compressor to pump and never shut down then the over pressure valve would be sounding off on the wet tank.

Mike

On edit: That (a governor) is one thing you need to have as a spare that travels with you all the time along with the end wrench that it takes to change it out. If you aren't mechanical inclined  find someone that will show you how to change it out as that is the heart of your air system. It isn't but 2 bolts and hose but important for you to be able to DIY

Thanks Mike.  I see several D2's online - are they universal or should I get a specific part number off my old one.

Re: Air Pressure down to 2psi overnight

Reply #33 –
Is is common for the D2 to leak when then engine is not running? I believe I read in an earlier post the leak can be heard with the engine off.  I am not that familiar with the air system, but if there is air leaking from the D2 when the engine is off, would that suggest a check valve is not holding?

Re: Air Pressure down to 2psi overnight

Reply #35 –
To answer a previous question:  Air is coming out of the wet tank when opened.

Re: Air Pressure down to 2psi overnight

Reply #37 –
Quote from: wolfe10 –
Only dry air?

No moisture., oil or white powder?

If so, that is GREAT!
Just dry air.  Something is leaking near the D2 I can hear the hissing.  Will investigate further on Tuesday

Re: Air Pressure down to 2psi overnight

Reply #38 –
Your wet tank if it's in the same place as my U-320 will be in front of the rear axle . When looking from the engine cowling forward it is behind the engine and in front of the axle (behind it in relation to the front end of the coach).

Re: Air Pressure down to 2psi overnight

Reply #39 –
Leak, plus, perhaps bad check valve.