Operation of the tag axle on my coach. I have a switch on the DS panel that is labeled Tag Dump. It was explained to me that the tag axle should raise when the air is dumped by this switch. As we started this trip, I pulled out from our lot to the street after I thought l had lifted the tag axle by pressing the tag dump switch. Not only did the tag not lift, the wheels locked up. A neighbor told me that the tag wheels were not turning. I thought that is normal as they are lifted. However when I examined closer, I found that the tag wheels were still lowered and the wheels were locked up and skidding. Are there brakes on the tag wheels? When I turned the tag dump switch off and watch for the travel light to come on, the tag wheels turn normally. So am I doing something wrong with my operation? On my Dynasty, the Valid system for leveling had a tag button which worked as I expected. I do not think this is normal for my Foretravel. Model and build number are in my signature. Thanks for any help.
When in reverse or using tag dump you are removing the air in the tag air bags. The tires are still on the ground but do not have the weight of the coach on them. When you apply the brakes when air is dumped they will lock up. The tags do not lift up off the ground
Well, the brakes do not appear to be releasing when I removed pressure from the foot brake to move forward or reverse, as the tag wheels stay locked up. On our concrete lot they left a mark as they skidded along, when we reached the gravel of the street, they continued to plow through the gravel. It appears that the brakes are remaining locked until I put ground pressure back on with tag dump switch.
Backing up or going forward without the tag dumped, no skid. Tag dumped backing up or going forward tag wheels skid or do not turn.
It seems like tag Dump sets the brakes not the foot brake.
I know nothing about tag axles (thankfully) but based on your comments and Turbojack's explanation of "normal" tag axle operation, it seems to me that you simply need to have the tag axle brakes serviced. Sounds to me (AGAIN I'm no expert) like the calipers are sticking and not fully retracting when brake pedal is released. Could be as simple as dirty/corroded slide pins.
With weight on the tag axle (bags inflated) you don't notice the sticky calipers because the wheels turn normally. However, the brakes pads, if they are indeed dragging, will tend to overheat and wear prematurely. Hence the need to have them checked and serviced.
We had a sticking caliper on the right rear corner on our coach. Totally wore out the pads and ruined the rotor, requiring replacement of both. I never realized the brake pads were dragging. I could not feel the extra drag in normal driving.
They make a "helper spring" kit for the brakes on our coaches. The springs are installed on the slide pins to help prevent the calipers from sticking in the applied position. I do not know if a similar kit is available for the tag axle brakes.
Helper springs on Meritor disc brakes (https://www.foreforums.com/index.php?topic=16318.0)
KIT15018 by MERITOR - Meritor Genuine Air Disc Brake - Spring Kit (https://www.finditparts.com/products/39506/arvin-meritor-kit15018) (one kit required for each brake assembly)
Just my armchair assessment. Take it for what it's worth.
Thanks, to both answers. It sounds reasonable that I may have a misadjusted brake pad on the tag. However it does not seem to show up at idle while releasing the foot brake to idle forward or reverse. You should see how it plows the ground with the tag dumped. The brake never seems to release at all.
Hi Herb, looks like your coach build number is a few numbers preceding the build of my 2002 U320. At some build sequence they changed to a "Lifting Tag". I believe we have a "Dumping Tag". This simply removes the air from the tag axle and allows all weight to transfer forward to the drive axle, thus giving us a little shorter wheelbase for tight turns. Somewhere in 2002 late production, they switched to the lifting tag I'm told...
Mine plows dirt and stone better than a tractor... I found that out coming out in my driveway the first time... I don't typically use the function unless on pavement. It'll still leaves tire marks on the pavement in places, but does give me a tad more turn capability if I am really squeezed and can't back up...
Not the best functionality in my mind. Sounds like yours is working just as good as mine :o
J & K
^ This ^
Most 2002 and earlier only release the tag axle, but don't lift it.
I read your post to my wife Willie, we had quite a laugh. We have a lot at Escapees in Livingston TX. We have concreted most of the lot and have a 2 foot mound between concrete and graveled street which we try to keep grassy. To keep from continuing to plow it up, just believe I will not dump tag anymore. Not a real tight turn to street so no need. Less damage to street and marking driveway to leave the tag undumped. Previously we had a Dynasty with lifting tag, definitely was necessary to lift it to keep from scuffing tires. Maybe not better, but different.
Thanks to all you folks that are contributing to my education.