2015 Ventana LE Porpoise

[skychs]

2015 Ventana LE 3636. 11,000 miles.

After camping ... slides come in ... jacks come up ... engine is started ... bags inflate ... pressures builds up around 125 psi ... then, when I put it into drive and start rolling the coach starts bouncing up and down. (porpoising). Its violent enough you can't go over 10 mph.

The PO told me about the issue when I picked it up. His solution ... extend the jacks, engine off, pump all the air out of the system with the brake pedal, retract the jacks, start the engine, build pressure to around 125 psi .... start driving. This has happened to me twice now in about 10 events.

I have search the forum, found a lot of good information but nothing specific about the bouncing. I spent all last weekend going over the auto leveling system as well as the air bag system. When I talked to the mechanic at the local RV service center he said it sounded like a valve problem, not opening and/or closing correctly.

Has anyone seen or heard of anything like this? Thanks
chuck

 

[RandyB]

I've never had the up and down event you are describing. However, your departure procedure is not following the Newmar recommendation. The slides in and/or out should be done "on the bags". This requires starting the engine to inflate the bags before moving the slides. On deploying the slides, the movement should also be done "on the bags". This requires that the air be released before the jacks deploy. It's automatic when you start the jacks, but sometimes the jacks hit ground before all the release is done. I cancel the deployment right after the air is released to allow full deflation.

This just might impact your departure problem, if the level controls get "confused" of which way they're going.

 

[Neal]

Chuck,

It sounds like you're due for new shocks. You can order Koni's sized for your coach or replace with what's on there and see if that helps. I use Excel Truck Group in Chester.

 

[skychs]

Thanks Randy
I guess I need to call Newmar today. With all the differences between the coaches (even different years of the same model) some of the information is very confusing.

The PO had me level before the slides. I swear I read the same thing in the Leveling brochure. Common sense backed that up by telling me to stabilize before you throw out the heavy slides. So much to learn. . Im trying.

Neal, with only 11,000 miles on the coach I hope the shocks are still good. RV Services of Va is taking a look at the coach on Friday. Andy recommended them over the larger center across the street. RV Services did my slide and generator service several weeks ago and were very fair.

 

[Gizmo]

Here is the change to the manual and it's for coaches mainly with Full Wall Slides.

 

[RandyB]

The PO had me level before the slides. I swear I read the same thing in the Leveling brochure. Common sense backed that up by telling me to stabilize before you throw out the heavy slides. So much to learn. . Im trying.

Yes it seems counter-intuitive, especially to my engineering brain. I resisted for a long time. I've now converted to the Newmar recommendation and have been OK with it. Still seems back-asswards, but that's what Newmar recommends. Many, many, many discussions on all forums regarding this exact topic.

It is a good thing for you to talk to the mothership (Newmar) and get their recommendations.

 

[skychs]

Ok, I just got off the phone with Newmar. The new memo was put out in 2015. My 2015 still had the original instructions. Its good to know Im not totally crazy.

To make things more complicated however ...... I just got off the phone with Freightliner. The service tech I talked to said he is shocked by the change in sequence by Newmar. He specifically said the jacks should be extended first from a chassis stand point. He did say the porpoising was due to under inflated air bags so at least I know what to look for on Friday when I take my coach in for service.

Here is a copy of the new sequence Newmar just sent me. Sorry if the photos don't come out.



Customer Service ([email protected])To:you Details

LEVELING AND FULL WALL SLIDEOUT SEQUENCE OF OPERATION
Provides step-by-step instructions for leveling the coach and operating the slideouts.
Jan 31, 2020•Knowledge Article
Contents
This article provides step-by-step instructions for leveling the coach and operating the slideouts.

IMPORTANT​

In the past, Newmar has recommended leveling the coach prior to deploying the slideouts. As of 2015, Newmar makes the following recommendation for the extension and retracting of slideouts.

Motorhomes, like all vehicles, flex in travel. Flexing may be different due to terrain and the coach’s fulcrums (resting on tires or jacks). As the coach flexes, this movement is more noticeable in the outside reveal on a wider slideout.
EXTENDING THE SLIDEOUTS AND LEVELING THE COACH

1. Park the coach on a reasonably level campsite.
2. Leave the coach at ride-height with air in the air bags (if equipped with air suspension) or on normal suspension (coaches without air suspension).
3. Plug the coach into shore power (if available) or start the generator to increase the voltage for better slideout operation.
4. Look at the “reveal” or “gap” of the two vertical wall trims around the slideouts to make sure there is plenty of clearance so the trim will not rub when extending the slideout. If the gap looks good, then the slideout can be operated.
· Note: Most often the gap will look best when sitting on the tires with the air suspension inflated (at ride-height), and not on the jacks.

IMPORTANT​

In the unlikely occasion that the slideout trim has inadequate clearances, try leveling or repositioning the coach and rechecking the clearances before extending the slideout.

5. Verify that the path of the slideout is unobstructed and free from any surrounding objects, both inside and outside of the coach.
6. Once the appropriate conditions are met, follow the operating instructions posted in your coach to extend the slideouts (image for example only).
7. Dump the air suspension (if equipped). This step is included in the auto-leveling process for most coaches.
8. Deploy the leveling jacks.
RETRACTING THE JACKS AND SLIDEOUTS

1. Retract the leveling jacks.
2. Start the coach.
3. Allow the coach air suspension to fill and return to ride height (units without air suspension will return to normal suspension).
4. Turn the engine off.
5. For a full wall slideout, visually inspect the front vertical trim for adequate clearance. The spacing should look even from top to bottom (see image for reference).

IMPORTANT​

In the unlikely occasion that the slideout trim has inadequate clearances, try leveling or repositioning the coach and rechecking the clearances before retracting the slideout.

6. Verify that the path of the slideout is unobstructed and free from any surrounding objects, both inside and outside of the coach. This includes any water or debris that may have collected on the slideout roof or the topper awning.

IMPORTANT​

Debris left on the roof or topper may prevent the slideout from sealing properly when retracted, as well as prevent the mechanical lock arms from closing properly when the slideout is extended.

7. Retract the slideouts. Inspect all slideouts for complete retraction.
8. If the coach is equipped with manual lock arms, make sure to lock them.
9. Unplug the coach from shore power when you are ready to depart.
Title


Thank you,

Mary Faulstich
Dutch Star Brand Specialist
1-800-731-8300
[email protected]

CONFIDENTIALITY NOTICE: The information contained in this email and any attachments are intended only for the use of the individual or entity to which it is addressed and may contain information that is privileged, confidential or subject to protection from disclosure under federal or state law. If you are not an intended recipient, you are hereby notified that any distribution or copying of this information is strictly prohibited. If you have received this email in error, please notify me and delete this message and any attachments immediately. You should not retain, copy or use this email or any attachment for any purpose, nor disclose all or any part of the contents to any other person. Thank you.

www.newmarcorp.com

 

[RandyB]

Thank you @skychs for the update. As you proceed to solving this situation, please report back for us all to learn.

The air bags inflate to a position, based on the control valve. Whatever pressure it takes to get into that position. The air tanks fill to a pressure.

If the bags are inflated while on jacks, that position is wrong when jacks are retracted. This could set things into motion that you are describing as porpoising.

 

[TJ&LadyDi]

Checking the "reveal" (gap) is the key in my experience. Rarely have I found the gap skewed, but it has happened, and I have always used the procedure Newmar laid out in the Full-Slide Letter-2. It has always worked for us.

TJ

 

[Old-RV'er]

FWIW-Mine fills up the air system/bags well above 100PSI, very close to 150 before release. You air bags might not be full, and the bounce may be on part of the suspension or something. Shocks would not cause this at low speed. And if it was me, and Newmar (who built the coach) said to do it a specific way, then that is the way I would do it.

You will hear a loud "pssst", noise when the bags are full so wait for it, before you move the coach. Although mine is newer than yours, following NM advice/suggestions for slide out operation, we have never had issues.

Please note: The equalizer leveling system in my opinion leaves a lot to be desired. We turn system on, push auto level, then turn system off, so all the air bleeds out of the bags, once air is out, turn back on, and manually level the coach, You must extend the front or rear jacks as a pair, then level side to side. Please read the manual Newmar has published for your RV. You will learn a whole lot of stuff. I review mine annually to make sure I have not forgotten something.