Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Discussions => Topic started by: Ed W on July 16, 2016, 12:15:49 am

Title: HWH compressor
Post by: Ed W on July 16, 2016, 12:15:49 am
Can I drive my coach with the HWH compressor removed?

Thank you, Ed
Title: Re: HWH compressor
Post by: Steve & Ginny Hill on July 16, 2016, 12:20:54 am
I don't think it will affect anything while in "travel" mode.
Title: Re: HWH compressor
Post by: Ed W on July 16, 2016, 12:26:20 am
Thank you
Title: Re: HWH compressor
Post by: Chuck & Jeannie on July 16, 2016, 08:13:39 am
I don't think it will affect anything while in "travel" mode.
Agree.  The HWH compressor is a "supplemental" source of air pressure...only necessary when the engine driven compressor is not running.  You will probably want to cap off any open air lines when the HWH unit is removed.  In most cases, the interface between the HWH pump and the main air system is protected by a check valve, but I wouldn't depend on that to prevent a big air leak.
Title: Re: HWH compressor
Post by: Ed W on July 16, 2016, 08:20:53 am
Ok, I had not thought about capping off the one line but will do that. The HWH compressor is out because of investigating leak and it was running too much. While looking I saw the white wire on the back of the compressor was burned looking and loose. While attempting to tighten the post broke off. I plan to take the compressor to a electric motor repair shop to get a new post and then continue the process of finding the leak.

Thank you for your comment
Title: Re: HWH compressor
Post by: Michelle on July 16, 2016, 08:21:25 am
Can I drive my coach with the HWH compressor removed?

Since you have an '03, if you have slides the bladder inflation may possibly not be maintained without the aux compressor.  You will not be able to deflate them to extend or retract the slides without it, either.  Just be aware.
Title: Re: HWH compressor
Post by: Chuck & Jeannie on July 16, 2016, 08:29:48 am
Good point - I didn't think about slides (not having any).  So on newer coaches, there are some parts of the air system only pressurized by the HWH pump?  That seems kinda dumb (to me)...  Why run a electric pump, with that big mechanical compressor chugging away at the rear end?
Title: Re: HWH compressor
Post by: Rich Bowman on July 16, 2016, 08:58:22 am
Yes--I think the bladder relies on the 12V compressor for air.  But I may be wrong.

I have also been tracking a leak in my 12V compressor system.  It appears to be in the slideout manifold.  I can actually hear it leaking.  But have not been able to bubble spray and find it.

Here's what I've been able to determine.  The manifold seems to have 4 components:  a venturi, a pressure regulator and two solenoid valves.  One valve controls the line to the bladder and one controls the line to the venturi.  If I turn off the manual shutoff valve at the manifold (it is on the supply side on the line from the compressor), the compressor does not run excessively.  Also, the bladder will stay inflated indefinitely.  My conclusion is that I have a leak in the exhaust valve that sends air to the venturi.  Still more trouble shooting to go.

You might try doing a little experimenting.  You may find that you can isolate the slide bladder, maintain seal and still be able to remove the compressor for repair.  Or your leak may be between the shutoff valve and the compressor.

Rich
Title: Re: HWH compressor
Post by: Michelle on July 16, 2016, 09:00:31 am
So on newer coaches, there are some parts of the air system only pressurized by the HWH pump?  That seems kinda dumb (to me)...  Why run a electric pump, with that big mechanical compressor chugging away at the rear end?

Because the big mechanical compressor isn't running when camped.
Title: Re: HWH compressor
Post by: Tim Fiedler on July 16, 2016, 09:37:12 am
Hmmm. On my 2000 I was under impression that air in main tanks fed system until the tank pressure fell to about 60 psi, and then my (undersized) 12 volt compressor took over slide bladder and leveling only.
Everyone should have a "spade" type connector on the hot or ground (better) dc input so that if running too long due to leaks easy to reach in and temporarily disconnect/connect pump Those more inclined (like me) put a pressure gauge in line near pump to see cut/in or cut out pressures , pace of leak down . Parts $25 at napa. Downside. One more place to leak
Title: Re: HWH compressor
Post by: Chuck & Jeannie on July 16, 2016, 09:40:19 am
Because the big mechanical compressor isn't running when camped.
Yes, I understand why it is needed when the engine is off.  But why not provide slides with pressurized air from BOTH the main air system (when engine running), and the HWH compressor (when engine off)?  Seems more efficient and logical to me.
Title: Re: HWH compressor
Post by: Michelle on July 16, 2016, 11:20:46 am
Yes, I understand why it is needed when the engine is off.  But why not provide slides with pressurized air from BOTH the main air system (when engine running), and the HWH compressor (when engine off)? 

I can't say that it doesn't, that's why in my first response I said that the bladders "may not be maintained" when underway.  One needs to look at the air schematic for a specific coach to know for sure. 
Title: Re: HWH compressor
Post by: Kemahjohn on July 18, 2016, 12:21:36 pm
I never had much faith in the 12volt compressor, so I added a 1 1/2 hp 120 vac compressor as an aux compressor.  My old U280 had one of those and I liked it!  Works well.
Title: Re: HWH compressor
Post by: redwing on July 18, 2016, 03:30:20 pm
So here is the scoop ,No problem disconnecting you 12 volt pump , your check valve will stop air from coming back.
Your Bladder rely"s on you pump only , It get's it's air from your s/o seal tank line 74 and line 77 provide the air . line 75 feed's that tank, and line 78 feed's optional awning . and that is how it work's
Rob
Title: Re: HWH compressor
Post by: Carl Cox on July 18, 2016, 11:49:34 pm
On our new to us 1997 U270 the small compressor never seems to come on...even when we are below 80 psi and not level.  I think it may not be working at all...can I trigger it manually to test?  Also, thought it would be nice to be able to air up my tires so thought about adding a 50 ft air hose with chuck....but the built in compressor looks pretty small for this job (and how to manually trigger it)...so was thinking just get a 120v portable air compressor (less than $50 I think at Harbor Freight)  Has anyone been down this path?  Any advice appreciated.
Title: Re: HWH compressor
Post by: Chuck & Jeannie on July 19, 2016, 08:47:06 am
Carl,

Welcome to the group!  Isn't it fun, learning all the new stuff about your new coach?

About your Aux pump.  To test it, drain the air pressure out of your air tanks.  You have found the water drain valves for your air tanks, right?  With tanks empty, turn your HWH system on, and try to use any of the "raise" arrows (the "UP" arrows).  Your Aux pump should come on - you will probably be able to hear it running in one of the storage bays.  If it does not run, you may have a blown fuse.  Look for a inline fuse holder on the power lead right next to the pump.  After you find the pump, that is...

For airing up your tires, two choices, and using the HWH pump is not one of them.  You should have a quick connect air hose fitting in one of your storage bays, with a valve to turn it on.  You can plug a hose into this fitting, and use air pressure supplied by the engine air compressor.  Can be kinda slow, depending on the cut-in/cut-out pressure of your compressor, and the desired tire pressure.

OR, as you said, you can use a small AC powered air compressor.  If you decide to go this route, get one that is easy to carry, with a small air tank, and 150 psi max pressure.  Makes airing up the tires a piece of cake, and you don't need to run the big engine (disturb your neighbors).
Title: Re: HWH compressor
Post by: Tim Fiedler on July 19, 2016, 08:55:22 am
Not Safe. Safety stands mandatory, there are threads that  festive parts and procedure to safely work under coach
Title: Re: HWH compressor
Post by: Caflashbob on July 19, 2016, 01:33:08 pm
Adding non dry air into the tires can cause the steel cord belts to rust over time.

The coaches air chuck uses dry air for safety of the air brakes