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Coach low at left rear
#1

596 is riding low on the left rear. I tried to adjust what I think is the ride height actuator. It is just inside the dual tire. I loosened the hose clamp and slid the rod down.

It really didn't seem to make any difference. Any ideas? I think it is about 3/4" low.  Thanks in advance for all the help.

David

 Rolleyes David Augspurger #596 2001
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#2

It is hard to gauge visually. Did you measure with a ruler or tape? How much did you move the rod? Have you had an opportunity to read the other post this week about adjusting height control valves?

Richard and Rhonda Entrekin
99 Newell, 512
Maverick Hybrid Toad
Inverness, FL (when we're home Cool )
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#3

Yes I am reading to try to learn the system. My tag is in the center position on the dash. The left rear is very low when the coach sits with no air. When I hook the shop air to it 
and run the engine the coach air up however the left rear is still low. I am looking at the tire from the top if the fender. I moved the rod approx 1/2". Do I need to let it off the bags and rear it up? I could try to fully air up the tag. 

Thanks
David

 Rolleyes David Augspurger #596 2001
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#4

Ok, thanks for the info.

First, look inside the front bottom of the fender well and you will see a 1 inch square piece of tubing that the fender skirts mounts onto. Newell measures the ride height from the bottom of that tubing to the ground. I run 11.5 inches from the bottom of the tubing to the ground.

Second we need to separate in your head, any height issues with the coach sitting and the coach engine running in travel mode. They may or may not be related.

For now let’s focus on the coach running, or or shop air, and in travel mode. Your coach is likely equipped with a park brake setup that can make setting the travel height a booger if you are not aware of it. When setting your travel height or leveling the coach, chock the wheels and RELEASE the park brake. It’s windy explanation, but in short the park brake on your coach is applied to both the drive and the tag axles. Because the suspension swing arms rotate in the opposite directions, the park brake will try to hold the coach from raising or lowering. So, chock the wheels and release the park brake.

Now, lower the coach below travel height. Put the coach in travel mode and allow it to settle out. Measure all four corners as discussed above. The side to side discrepancy is adjusted using the ride height valves on the rear axles. The relationship between adjustment on the vertical arm and movement you want to achieve is pretty close to 1 to 1. Move the arm 1/2 inch, you get 1/2 inch on the ride height.

If you need to adjust the front ride height, you should be aware of two critical concepts. One, the ride height adjustment in the front is driven from the rotation of the sway bar. It is NOT a 1:1 adjustment. It is super sensitive. 1/16 adjustment on the rod gives me almost a 1/2 inch at the ride height. Secondly, anytime you adjust the front ride height, the toe in will change. Be aware of that.

As discussed in another post, each time you change an adjustment on a ride height valve, you must lower the coach below ride height and allow the travel function to raise it to ride height. If you do it any other way you WILL NOT get repeatable results.

Here is how I adjust ride height. There are other ways, but they require you to reach over the tires and my arms aren’t that long. I chock the coach so it cannot crush me. I crawl between the drive and axle tires head first. At the top of the drive axle you will see the vertical arm of the HCV is attached to a stud on the top of the axle. I lube the stud with grease (or spit) and slip the arm off. I then can pull the arm toward me enough to reach the clamp on the rubber “P”. I loosen it, make the adjustment I want, retighten, and slip the arm back over the stud. Remove the cribbing, lower the coach, and let it return to travel. Then I take my measurements. I remind you again on your era coach, the parking brake must be released to get a correct reading.

On the second issue of the coach dropping as it sits, that is an issue that could be caused by leaking air bags, leaking connections to air bags, or faulty valves in the leveling six pack.

Richard and Rhonda Entrekin
99 Newell, 512
Maverick Hybrid Toad
Inverness, FL (when we're home Cool )
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#5

Thank you very much for the info. I will get to work and let you know what I come up with. I would have never figured all that  out on my own.
Thanks
David

 Rolleyes David Augspurger #596 2001
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#6

David,

This may help.

http://newellgurus.com/showthread.php?tid=4957

Richard and Rhonda Entrekin
99 Newell, 512
Maverick Hybrid Toad
Inverness, FL (when we're home Cool )
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#7

Richard thanks for re-posting this.

1998 Coach 484
1997 Suzuki Sidekick toad. 
Cheers.  
 
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#8

I rebuilt all my six pack valves and resurfaced the area where they mount as it was very corroded I also put a valve in the line that goes to the airbag so I could turn it off got the coach back up the ride height turn the valve off and the next morning left rear was sitting on the ground so I know that it is not the six pack valves the next question is is there some kind of valve for the tag axle or maybe I have a leak in one of the airbags or the lines for
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#9

Keeping in mind we are no better at armchair diagnosis than the info we have to work on.

Let’s separate this into two issues. One, is the coach now at correct ride height with the engine running? Did you resolve that? If so, how? If not, what is the air pressure produced by the engine compressor. It MUST be 120 or higher.

It’s clear the coach settles overnight. You have confirmed it is NOT the six pack with your shutoff valve. Great work!! So you obviously have a leak in airbags, airbag tanks, or the tubing. Some leaks in airbags are impossible to detect because the leak area is hidden under the bottom plate. Search for Goodyear air bag burping.

To answer your specific question. The tag system receives it’s pressure for a give side from the drive side left or right air bag tank. These are big square tanks welded as part of the frame. A small line will lead from the drive air tank to the tag air tank. When you get to looking under there, you will see only one tag air tank. It has a hidden divider welded in the middle. Now the air line coming out of the tag tank and feeding the tag bag has two three-way valves in it. One of the three way valves is actuated when you want to release air from the tag. When actuated it closes the path to the tag air tank and opens a path to atmosphere. Clever, actuating the valve isolates it from the drive air bags so you don’t lower the entire side of the coach.

You will find a second identical three way valve in series with the one discussed above. However, it’s normally open port will be connected to an air line that is eventually connected to full pressure coach air. So when that valve is actuated, it closes the path to the drive bags and opens a path to full coach air pressure, thereby increasing the pressure in the tag bag without increasing the pressure in the drive bag.

Richard and Rhonda Entrekin
99 Newell, 512
Maverick Hybrid Toad
Inverness, FL (when we're home Cool )
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#10

Got the problem with the ride height when the coach is running resolved. I fix quite a few misc air leaks and now I have
120psi air with no problem. I think that was the problem. I just have to resolve the air bags on the left rear leaking overnight. I will get under the coach this weekend and do some more looking. As always thanks for the help, I am learning the systems as I go.

Thanks
David

 Rolleyes David Augspurger #596 2001
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