1 wheel locks up when breaking help!

Well if the self adjusters are working correctly, they would reset right back where it was. I assume.

 

why did you swap shoes?

you didnt by chance put an extended life shoe on a normal s-cam did you ??????

 

Just a statement and not meant to come off the way it's probably going to sound, but here goes:

Antilock Braking System only pulsates braking pressure to the shoe to allow for a little bit of roll, in theory, to avoid jack knifing the trailer due to brake skid. It is accessed via foot pressure on the pedal. Yes, it is controlled from inside the tractor and monitored by the ECM.

What you are describing is traction control or anti-slip, which requires a differential. Traction control does not apply to trailers. A trailer tire losing traction because of spinning is both impossible and irrelevant. Impossible because there is no power to the trailer tire to cause it to "spin out" and irrelevant because traction control has nothing to do with ABS...with the exception that they are both supposed to help avoid skidding.

Many of these new tractors have an anti-roll system as well. A sensor detects a hard turn or a balance problem and will hit your brakes for you if you don't correct it yoursef. It has to be a pretty hard turn to engage.

Regarding the O/P's issue: this may be simplistic, but I've had trailers do this and took them to the shop for adjustment. It sounds to me like your brake adjustment may be ever so slightly too tight on that axle. Have you tried backing it off just a hair?

 

I had one do that for a while. Ended up being a better grade of brake shoes on that one wheel so it was doing more braking than the others. Swapped the rest of them with the better shoes and the problem stopped. There is an amazing difference between the grades of shoes.

 

you are right injun--i shouldnt have written spinning--the abs sensor compares the rate of speed on each hub and sends that back to the ecu--then pulsing the brakes if need be--if it senses them locking up or not
failure of an abs sensor will not lock up a brake--it will only revert back to a normal(non abs) braking style

 

This is pitiful..
The guy already said he doesn't have antilock brakes----- yet alot of people keep replying that his problem is antilock sensors and such..

I can't assume anything at this point, not after reading all this, but if I were to guess it has to be that since he has no anti-lock it must be an older trailer, which also means it probably has manual slack adjusters---
And another real good reason to assume that is, as you've already pointed out, it would totally be a big waste of this guys time trying it out with automatics "backed off", because they're gonna automatically re-adjust as soon as the brakes are applied-----

But--- If they are indeed manual slack adjusters, and they are indeed backed off, but still scootin' the tires when he stops, then somethin somewhere has went bad wrong {or probably the wrong way} with the backin off?????

But the main thing I'd like to know is--- How does the guy that said "it might be grease inside the drum" figure that's gonna cause this wheel of brakes to grab before the other side?????

At this point all I know to tell the guy is to pull the carter-key out of the pin in the the slack adjuster, then remove the pin out of the clevice on the threaded rod from the brake chamber, where he needs to clamp a pair of vice-grips on the service air line-----
Then go try it and see if it'll still scoot the tires and report back----- I wouldn't be too suprised if somebody in here says it will..

 

yes we know he doesnt have abs----but thanx for pointing it out

 

Have you greased your brakes lately?

 

R&R brakes. Can be a whole host of issues. (this coming from a car guy)

Warped drum, mismatched or improper shoes, mis-adjusted pistons. In the case of air brakes, it could be an air chamber issue too I guess. Could be a bad valve in the air splitter. (yes, it DOES have valves in it.) Allowing too much air to that one chamber.

Take it to a reputable mechanic, safety isn't something to leave in the hands of the general public making guesses. Next to the driver, the brakes are the most important safety device on a truck.