Empty Tanker Trailer Jumps, Skips, Bounces while empty.

Pulling an empty tanker, while braking the tandems jumps, skips and bounces. Feels like the ABS is applying hard braking and then releasing, over and over again. Any ideas?

 

Have the shop look at it.

Some trailers like to be up on one axle when empty and that might be a trigger. I don't know anything without physically doing the things to your trailer you describe and observing it's behavior. If your ABS is not correctly behaving, the shop will get it sorted.

 

The shop has looked and the problem still there. Not only this trailer but several trailers we have are doing the same thing. A little hairy on a slick road.

 

Your unladen weight value needs to be changed in the rss/abs ecm.

Right now it’s set to low. So when your trailer squats during braking the air bag pressure up above the value and thinks it’s loaded, which applies the brakes harder locking them up, which makes the abs release the brakes and spring boarding the trailer into the air.

Best thing to do is get a weight for just the rear of the trailer hooked to a truck. Add 1000lbs and have that entered for your unladened weight. Also, have them move the PSI (from the air bags) up 2-5 psi.

And if I remember right, the ecu wants Kg not lbs so there maybe some math involved to change it over and divide it by the number of axles.

 

Common problem, dangerous in rain and snow. I found by jabbing brakes hard, if somehow resets and goes away. Otherwise was a mystery to Me, and any Mechanic I talked to . 01 Great Dane

 

Do other trucks have that issue to or just yours?

 

kind of having same issue. when cold out you barely apply pressure to the peddle. loaded 88000 lb super bees lock right up. application gauge spikes over 50 psi. scary on north west territory roads

 

I’d say it’s likely your truck. I don’t see all trailers suddenly having the same problem. Your brakes may be out of adjustment. Also check your glad hands are secure/stable and not leaking air. Drive forward slowly (2 mph) and apply your trailer hand brake located near your steering wheel.

 

I had a “rash” of @6 2010 to 2013 model Heil’s and Stephens trailers all with Wabco RSS and Hendrickson Intrax suspensions. I’ve had to make the adjustment to there unladen values. After talking with a Wabco rep. We checked suspension bushings, shock absorbers, s-cams, slack adjustments, etc and finally resetting the values is what fixed it.

I’ve found as these suspensions wear this becomes a problem. I first found it on a trailer that was less than 3 months old.

 

We have several trailers having this issue.