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Topic: Tag Axle wheels lockup (Read 515 times) previous topic - next topic

Tag Axle wheels lockup

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.
Herb and Willie
Escapees 90802
2014 IH-45 Build 6581
2002 U320 40' AGDS Build 6021 Sold
1999 U320 36' No Slides Sold
2007 Monaco Dynasty Diamond IV Sold
2005 Discovery 39 Sold
1986 20' Wilderness TT,  Died a natural death after floods, etc.
Walldog's Journeys
And Willie Said

Re: Tag Axle wheels lockup

Reply #1 –
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
2014 ih45  (4th Foretravel owned)
 1997 36' U295 Sold in 2020, owned for 19 years
  U240 36' Sold to insurance company after melting in garage fire
    33' Foretravel on Dodge Chassis  Sold very long time ago

Re: Tag Axle wheels lockup

Reply #2 –
Quote from: turbojack –
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.
Herb and Willie
Escapees 90802
2014 IH-45 Build 6581
2002 U320 40' AGDS Build 6021 Sold
1999 U320 36' No Slides Sold
2007 Monaco Dynasty Diamond IV Sold
2005 Discovery 39 Sold
1986 20' Wilderness TT,  Died a natural death after floods, etc.
Walldog's Journeys
And Willie Said

Re: Tag Axle wheels lockup

Reply #3 –
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

KIT15018 by MERITOR - Meritor Genuine Air Disc Brake - Spring Kit  (one kit required for each brake assembly)

Just my armchair assessment.  Take it for what it's worth.

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: Tag Axle wheels lockup

Reply #4 –
Quote from: Chuck & Jeannie –
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.

With weight on the tag (bags inflated) you don't notice the sticky calipers because the wheels turn.  However, the brakes pads, if they are indeed dragging, will tend to overheat and wear out 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.

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.
Herb and Willie
Escapees 90802
2014 IH-45 Build 6581
2002 U320 40' AGDS Build 6021 Sold
1999 U320 36' No Slides Sold
2007 Monaco Dynasty Diamond IV Sold
2005 Discovery 39 Sold
1986 20' Wilderness TT,  Died a natural death after floods, etc.
Walldog's Journeys
And Willie Said

Re: Tag Axle wheels lockup

Reply #5 –
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
Jeff & Kristen
2002 U320 build #6039
Living the Dream!

Re: Tag Axle wheels lockup

Reply #6 –
Quote from: Beeman –
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...


^ This ^

Most 2002 and earlier only release the tag axle, but don't lift it.
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320
 

Re: Tag Axle wheels lockup

Reply #7 –
Quote from: Beeman –
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

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.
Herb and Willie
Escapees 90802
2014 IH-45 Build 6581
2002 U320 40' AGDS Build 6021 Sold
1999 U320 36' No Slides Sold
2007 Monaco Dynasty Diamond IV Sold
2005 Discovery 39 Sold
1986 20' Wilderness TT,  Died a natural death after floods, etc.
Walldog's Journeys
And Willie Said