Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: sedelange on November 14, 2014, 01:04:56 pm

Title: Tag Axle wheel dragging
Post by: sedelange on November 14, 2014, 01:04:56 pm
When driving at slow speeds, the right tag axle wheel stops when you apply the brakes even slightly, causing the tire to drag.  Brakes have been lubed and adjusted,  still stops.  Curious if the air pressure on the tag is low.  What should the pressure be?  Any other suggestions?
Title: Re: Tag Axle wheel dragging
Post by: Kemahjohn on November 14, 2014, 02:12:07 pm
Sure sounds like you don't have any weight on that side.
Title: Re: Tag Axle wheel dragging
Post by: sedelange on November 14, 2014, 02:17:36 pm
It does have enough to put a black mark on a paved parking lot.
Title: Re: Tag Axle wheel dragging
Post by: Pamela & Mike on November 14, 2014, 03:07:18 pm
Steve,
If you determine that your tag air bags have plenty of air pressure along with the tire here is another thought. With your unit being an '05 it should have an ABS sensor on that wheel that should keep it from locking. I don't know if it is active all the way to a complete stop but it should be. You may need to check the spacing of the sensor. Also check the ohms of the sensor to see if it is shorted out.

Pamela & Mike
Title: Re: Tag Axle wheel dragging
Post by: sedelange on November 14, 2014, 04:27:59 pm
ABS usually doesn't work at extremely slow speeds. I don't get any dragging during normal operation because the tire temps show no increase.
Title: Re: Tag Axle wheel dragging
Post by: Pamela & Mike on November 14, 2014, 04:37:30 pm
Steve,

Then with everything that you have checked in the brake system it does seem like air pressure or lack of.

Pamela & Mike
Title: Re: Tag Axle wheel dragging
Post by: sedelange on November 14, 2014, 07:33:17 pm
Does anyone know what the pressure should be in the tag axle system?
Title: Re: Tag Axle wheel dragging
Post by: John S on November 14, 2014, 08:02:03 pm
Have you weighed your rig.  That will tell you how much weight you are carrying.  I can lock mine up on both sides pretty easy if I hit the dump button. It does not lift but pulls the pressure off it.  That is what it sounds like is happening.  I will have to look up the pressure on the bags or you can call or email James Triana and get it from them. They probably have it easy to hand.
Title: Re: Tag Axle wheel dragging
Post by: Michelle on November 14, 2014, 08:11:52 pm
Does anyone know what the pressure should be in the tag axle system?

The manual for our '03 (should be similar) indicates there's a 100 psi regulator on the tag axle for the lift mechanism.

Title: Re: Tag Axle wheel dragging
Post by: sedelange on November 14, 2014, 09:39:12 pm
The 100 psi regulator is for the tag lift.  I need the pressure for when the tag is down.  I do see there are 20psi switches in the manifold which means the pressure should be above that.  If the drawing of the manifolds is complete, then the air pressure in the tag would be the same as the air pressure in the drive axle bags.  Now I am really curious why there is insufficient pressure on the tag wheels or if that is even the problem.  UGH
Title: Re: Tag Axle wheel dragging
Post by: sedelange on November 14, 2014, 09:43:00 pm
I forgot to say thanks for the drawing, Michelle.  My books are in the coach at Cummins.  They were attempting to contact Foretravel today for suggestions. 
Title: Re: Tag Axle wheel dragging
Post by: David Bethard on November 14, 2014, 11:33:00 pm
You mentioned "lubed". If the brakes are improperly greased they will drag and possibly do serious damage. Brakes should only be greased when linings are changed and again at mid life of the linings following the Meritor proceedure.
You may already be aware but thought it should be mentioned because of the high cost to repair if driven with brakes dragging. There's been many threads concerning brake lubrication in the past.

You may want to check the slack adjuster on that wheel.
The brake can seriously overheat without affecting tire temperature.
Title: Re: Tag Axle wheel dragging
Post by: sedelange on November 15, 2014, 12:46:30 am
Brakes were cleaned and the status of the grease was determined in an effort to determine the reason the wheel was stopping.  Brake temperatures were normal.  Hottest temperature recoded was 103F and that was after driving through town. 
Title: Re: Tag Axle wheel dragging
Post by: sedelange on November 20, 2014, 08:46:17 pm
The problem is finally solved.  Turns out the solenoid that allows air into the air bag isn't working. Finally was able to get system to fail while in the shop.