Air dump control valve

[tufffish]

air will not stay in front of coach. back air stays until let out. we need to locate the air dump control valve. does anyone have suggustions on where to look? no help calling monaco. thanks to all.
2001 monaco signature

[jacwjames]

Provided you don't have another leak somewhere the dump valve for the front is on the firewall.



You might check your manual, in mine it lists the part number of the dump valves.



My front is MAC 225B-601BAAA
Rear is Allen Air 36BXA-HB

[jacwjames]

Here is a link to download an PDF copy of your manual.

https://www.monacocoach.com/resource..._Signature.pdf
I checked the dump solenoids are listed on page 10-313






Also, you may want to request electrical schematics for both the house and chassis. Much easier to use in PDF form.
https://www.monacocoach.com/technical-assistance

[vito.a]

Welcome to the forum.
Are you sure it's the dump valve?
A large percentage of the time (maybe 90%+) the leaks are in the air solenoid valves, or "6 packs". They need new o-rings installed both inside the solenoid and also where the air lines insert into the solenoid.

You need to get the coach up in the air because after you locate the leaks you need to bleed the air down to work on the solenoids. If you do not have a lift, build some ramps from 2" X 12" boards stair stepped together.

Someone also posted a link to a leak detector spray product on Amazon that is superior at finding leaks.
https://www.amazon.com/dp/B001B00LOS...v_ov_lig_dp_it

This process takes time and patience and very few shops have either. HWH will work on your system if you are near Iowa or Paul Maddox.

A good way to start would be to search this section and the Roadmaster chassis section and pre-purchase the o-rings needed. Mike Canter suggests you use Dupont Viton orings. The internal oring is a -019 size, the large one on the bottom is a -028 and the small one on the bottom is a -015.

Then remove the 6-pack valves in both front and rear and rebuild them. Label all wires and air lines. It will help to have a special "pin wrench" tool and cannon plug pliers to get the valves apart.

Here are some links to get you started:
http://www.irv2.com/forums/f115/air-...em-160935.html

You Tube video:

https://www.youtube.com/watch?v=ChLo7eTBRdE

http://beamalarm.com/Documents/hwh/h...sassemble.html
Hope this helps.

Contact Paul at AZPETE on the Irv2 forum. He works for HWH and can answer your questions. His email is pfmaddox@att.net<mailto<img src="ima...maddox@att.net> and his phone number is 602-549-3638. He is a Commercial Member and has posted that his phone is always on, and if not answered, leave a message.

Probably more than you wanted to know but it's the right way to fix these older air ride coaches.

[tufffish]

it worked ok last week when i ran the coach for 15 minutes, which i do every week if we are not using it. this week, crank up and nothing. that's why i thought it must be a valve or switch that hung. it is getting air to the front of coach, just not to the air bags. had a guy check for leaks with soapy water and sis not find any.

[rpasetto]

Originally Posted by tufffish

it worked ok last week when i ran the coach for 15 minutes, which i do every week if we are not using it. this week, crank up and nothing. that's why i thought it must be a valve or switch that hung. it is getting air to the front of coach, just not to the air bags. had a guy check for leaks with soapy water and sis not find any.

So if I understand what you are saying, the front air bags stay soft with the engine and compressor running ... but air is getting to the front.

As Vito said, a large part of air leaks can be traced to the 6-pack valves. Four of the six solenoids control air to the bags when you are in level mode. Two others are responsible for air to the bags, along with the ride height valve, when the coach is in travel mode. To give you an idea of how things are connected, I attached two diagrams from HWH documentation. There is a great deal of diagnostic and repair info available online from HWH at: Welcome to HWH Corporation There's a lot to read there about diagnostics alone.

If you post what you checked to see that air is getting to the front and also whether the system is in travel mode or in level mode when you are running the coach that may help others help you diagnose the problem. Hopefully Vito, AZPete, or one of the other experts here, will weigh in and explain things better than I have.

[tufffish]

is this the aux 12v air supply? this pump is always leaking air. is this right?

[tufffish]

Originally Posted by tufffish

is this the aux 12v air supply? this pump is always leaking air. is this right?

there are 2 solanoids near this. are they ones i should be checking?

[jacwjames]

The 12 volt air supply is there to maintain air pressure while you are parked. You should be able to hear it running periodically to keep the air system pressurized. If the rig is loosing level in a short period of time then you have excessive air leaks.

[vito.a]

HWH uses the Thomas 405ADC38/12 Piston Auxiliary Air Compressor. This is the same air compressor used in dental offices. It is very quiet compared to some of the other air compressors.
It has an open armature and tends to get dirt inside the motor and quit. They can be rebuilt or replaced.
A rebuild kit is $229.
https://www.ebay.com/itm/NEW-OEM-THO...4AAOSwG21eVpkW
A new compressor is $364.72
https://www.ebay.com/itm/THOMAS-405A...0AAOSwHYpf-P0L

Some folks install a shield around the compressor to protect it.
I suppose they can leak, but Monaco installs a one way valve so they do not let air out of the system.

[azpete]

hey vito, i do very limited service work anymore, and only by hwh assignment.
owners orders to slow down.
age has caught up with me. i do provide assistance for anyone working in hwh product.
im always available on the phone or email. pfmaddox@att.net
1 602 549 3638
if you need help. please contact me. i can help.
the hwh part number for the air solenoid ring kit is RAP6554