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Newell Gurus
Tag brakes dragging - Printable Version

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+--- Thread: Tag brakes dragging (/showthread.php?tid=5642)



Tag brakes dragging - bikestuff - 08-28-2020

Gurus,

So yesterday I was driving the coach in rural Ohio.  All of a sudden my tire air pressure monitor system told me that my driver’s tag tire was loosing air.   At the same time, I started smelling the unmistakable smell of hot brakes.

I pulled over and checked the air pressure.  It was fine but the tag wheel was very very hot.   My belief was that the caliper was jammed in the “on’ position.  I tried a couple of things to free it up.   1) I banged on caliper with a hammer And 2) I rocked the coach forward and reverse with the brakes applied.  This helped but did not solve the issue.   

I drove carefully to my destination 30 miles away.   I watched the temperature of the wheel all the way.  The temps were approaching 200f by the time I stopped.

It turned out that there was a truck mechanic right across the street.   They dropped what they were doing to come over to coach and take a look.   They pulled the wheel off and pulled the caliper loose.   It turned out that the rubber boots that keep grit from jamming the guide pins were missing.  The guide pins were completely dry of grease.  With the caliper loose and the pads removed, it was easy to push the guide pins out from the inside.  

Once they greased the pins and reassembled it was clear that they had solved the issue.  (The caliper moved easily in and out by simply pushing and pulling on the outside). The mechanics got new pads from the parts store and I was back in business.

I tell you this story to share a couple of insights.  

1). I never have monitored tire temperatures on a regular basis while driving.   If I had, I might have known that I had a problem earlier.

2). The mechanics said that this sort of failure is very common.   The tag wheels gets coated with dust blown up by the other wheels.   This contaminates the guide pins and causes them to jam the caliper movement.  

I am not sure how long the fix will work and will do more research when I get home.  Hopefully this story will help someone down the road.

Bill


RE: Tag brakes dragging - bestgenman - 08-29-2020

Bill,  when I bought 567 in 2010, a thorough inspection of the underneath side was performed.  One of the most significant items found was drive axle calipers not moving.  The boots were missing and since stuck, only one pad was making contact on both sides.  The tag boots were missing as well but not stuck.  I made some delrin plugs with a bead and used a piece of 1-1/2 coolant hose and hose clamped to the caliper and the plug.  They are still there and in fine shape.  Checking the boots is a yearly pre season inspection as well as verifying the calipers are free on all wheels.

The drives were a different story, one wheel seal was leaking which required the caliper removal. Both calipers were replaced with rebuilt calipers from Belgium.   That’s another story!


RE: Tag brakes dragging - Jackflash - 09-20-2020

Just had the same thing happen to me, right tag. Trying to get it taken care of before we leave for Michigan in about a week.


RE: Tag brakes dragging - bikestuff - 09-20-2020

Jack,

So..when they take off the wheel....you can get easy access to the calipers. Pulling the pads will allow you to see if the caliper can move. It should be free and easy to move in and out. Like I said above the fix was to grease the guide pins.

I have no idea how long this fix will last. I saw a Bendix video that said that the pins do not need grease. For sure I will be on the hunt to find boots to cover the pins.

Good luck!
bill


RE: Tag brakes dragging - encantotom - 09-20-2020

when i bought my 02, several of the pins were frozen as well.

tom


RE: Tag brakes dragging - DK on the road - 09-21-2020

I Find this a timely issue for me also. I have much more brake dust on my tag wheels than any other axle. Its time for me to R & R the wheels for a thorough examination of the brakes.

I am a big proponent of Tire pressure monitoring systems (TPMS). Its another gauge of whats going on. I recently overloaded a trailer, I knew I was overloaded, I watched the temperature climb on the heavier side of the trailer. I didn't know what temperature the tire would be damaged at, but it did blow out.  I wish I could be more informative as to what the temperature is for failure, but as it is unfolding on the highway, I didn't look at the gauge. The lesson is, don't let it get hotter than the rest. So as a precaution, when I got to my destination I removed my axle bearings and they were toast.

As for guide pins, they should not be greased for the following reasons. If these pins do not exist in a air tight, sealed environment, grease can retain dirt and gum up sooner than a dry environment. Unless your into a R&R on some scheduled basis, I would advise against grease, instead, remove corrosion and make very clean.

The S cam drum brakes on older Semi truck and I'm sure older Newells, are less prone these type of problems, but they have less brake swept area and retains heat more than the disc brakes.


RE: Tag brakes dragging - Jackflash - 09-22-2020

My coach runs Knorr-Bremes disc brakes, the service manual says to grease the fixed pin bearing with green grease and the floating pin with white grease. I pulled the wheel and the pins were locked to the point that I had to remove the carrier (those 6 bolts took an hour) to take it and the caliper off together. Once I had the pins out I turned a dowel to fit tightly in the pins so that I could mount them on the lath and hit them with fine wet dry sandpaper and then a buffing pad. They ended up smooth and shiny, calipers slide easily and smooth as silk. Put everything back together yesterday and made a boot for the fixed bearing pin out of radiator hose with a cap turned form a 2" dia dowel. I'll have to test them out in a day or so.


RE: Tag brakes dragging - Jackflash - 09-24-2020

This is what the pins looked like by the time I put them back in.         The long one is the fixed bearing pin and the other the floating one. I couldn't get all the pitting out but it slides smoothly. Here is the boot I made, it should hold up a little better than the original.        


RE: Tag brakes dragging - encantotom - 09-24-2020

nicely done

tom