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Topic: Raising coach height while driving? (Read 517 times) previous topic - next topic

Raising coach height while driving?

I've seen a couple people mention that they either raised or lowered their coach height for a short bit while driving - for example to clear a driveway apron, etc.

How is this done when in travel mode with the parking brake off?

Chris

Re: Raising coach height while driving?

Reply #1
Excerpt from HWH 600 Series Service Manual:

8. DUMP AND RAISE BUTTONS  The "DUMP" AND "RAISE" buttons are for operator convenience.  They allow the coach to temporarily be raised or lowered to clear obstacles while moving.  These are momentary buttons.  When released, the coach will return to ride height if the ignition is on.  These buttons will operate with the system on or off, and the ignition on or off.  If the system is on, the system will turn off when the button is released.  The "DUMP" and "RAISE" button will lower or raise the whole coach.  If they are not working correctly see Part 8 of the REPAIR STEPS.
CAUTION: Do not exceed 5 mph or travel long distances when using these buttons or if the coach is not at the proper travel height.

http://www.hwhcorp.com/ml11148.pdf
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Raising coach height while driving?

Reply #2
My folks always said to read the instructions...  Thank you for the direct reference.

Yup, that's how our operates.

I was misunderstanding the posts.  I thought folks were able to maintain the desired height without having to hold the buttons.  I couldn't figure out how the system was allowing for that.

Chris

Re: Raising coach height while driving?

Reply #3
Chris,

On most older coaches ('90s model years) the RAISE and LOWER buttons are "momentary" - they only work as long as you hold them down with your finger.  At some point, the HWH system was modified/updated, and these buttons became "latching" - you push it once and it holds that setting until it is released.

I don't know where in the model years that change became effective - somebody with a newer coach may chime in.

Here is a old thread discussing this subject:

Manual Control of the Airbag System
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Raising coach height while driving?

Reply #4
Apparently, when HWH went to the 2000 Series system, the button function changed.  Here is the relevant excerpt from the manual:

"The "RAISE" and "DUMP" buttons can be used at any time the network is active.  The park brake does not have to be on.  If the ignition is in the "ON" position and the park brake is off, the "RAISE" or "DUMP" buttons will latch in.  The vehicle will raise or lower completely and stay in that position.  The vehicle cannot return to ride height until the "TRAVEL MODE" button or the "CANCEL" button is pushed or the vehicle exceeds 10 M.P.H, putting the system in the TRAVEL MODE."

http://www.rvtechlibrary.com/chassis/HWH2000_owners.pdf
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Raising coach height while driving?

Reply #5
We have an '03 and it works as Chuck stated in his last post.
Richard & Betty Bark & Keiko our Golden Doodle
2003 U320T 3820 PBDS
Build # 6215
MC # 16926
2016 Chevrolet Colorado 4X4 diesel

Re: Raising coach height while driving?

Reply #6
Chuck, not time to read all the attachments....but see if this caution works....do not drive in Dump mode.  If that means the coach is resting/rubbing on the tires.  That correct, or not?  I am fairly sure I read that but maybe not accurate reference when I saw it.  Maybe it okay for very short, few yards distance?  Hmmm....not sounds good to me, but...

mike
Mike
2001 U320 4010 Build 5878 (Gus)
Wrangle Unlimited Toad
Nacogdoches

Re: Raising coach height while driving?

Reply #7
Mine latch in on the '03.
Dave W. (AKA Toyman )
'03, 270, 36', Build 6095, Pulling whatever I hook it to.

"Don't cry because it's over. Smile because it happened."
Dr Seuss

Re: Raising coach height while driving?

Reply #8
Mike,

I agree - I would not want to move my coach with air dumped, unless it was a emergency.  I think the manual height control function of the HWH system is more commonly employed in the "Raise" position...going up steep driveways, etc.

I think I did read on the Forum that the new model coaches have to be lowered down to the mechanical stops to pass through some of the door openings at the Foretravel factory.  Urban myth?
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Raising coach height while driving?

Reply #9
On the nineties coaches, the tires are pressed against the underside of the floor when air is dumped from airbags, so I do not know how moving with air dumped would not cause major damage. The underside of the floor on my coach showed some tire rub damage when I bought the coach in 2010. I have inserted half inch spacers above each air bag to mitigate this, however, with ride height unchanged, the front tires rubbed on the floor when I hit a Mexican Taupe at 30 mph causing some new damage. I intend to raise the ride height a half inch. Since inserting the half inch spacers, the tires do not touch the floor with the air dumped if parked on level ground. If parked such that one or more corners of the coach is/are lifted to maintain a level floor, the tires will still press against the underside of the floor. Someone on Foreforums reported repairing floor damage caused when air was dumped.
Wyatt
96 U320 40 WTFE, build 4943
84 Toyota Supra towd
2015 Jeep Wrangler towd
Victoria, BC, Canada

Re: Raising coach height while driving?

Reply #10
Early unihomes had my favorite system.  Three levers thst adjusted the ride height valves on the mounted side.

Always said I would add that to a later coach.

You could cock the suspension system going down the road to compensate for cross winds.

Or raise the front or rear separately independently.

That being said the unicoach requires much less countersteering.  Gentle steering wheel pressure is normally all that's needed.

Heavier?  Lower height?  Round roof better in side gusts?  Lower center of gravity?  All or none of the above?
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4