Brake problem??

[xtruckerbob]

I had to take my tractor to the shop for some warranty work and my brakes kept hitting hard enough to slide for about 1 to 2 seconds at a time. Just going down the road every thing was ok the probem was when I touched the brake pedal even when I just to kick off the cruse. I had to unplug up my trailer to get home. Anyone ever this problem I wondering if its a truck or trailer. I have a Chevy Duramax

[tnchuck100]

It sounds like your brake controller is way out of adjustment. You did not state what brake controller you have. Is it after market or factory equipped?

Chance a child messed with the adjustment?

Beyond that the controller has probably failed.

[Iraqvet05]

Factory brake controller or an aftermarket?

[xtruckerbob]

It is a factory

[xtruckerbob]

I turn it all the down and made no differance

[tnchuck100]

Good chance the controller has failed.

[xtruckerbob]

toward the end it wold hit a even with out using to brake

[tnchuck100]

That would shed some light in another direction.
Now I would suspect maybe some frayed wires in the trailer connector. Maybe a strand of wire from the 12V pin intermittently touching the brake pin.
Another possibility is a defective break-away switch.

[Jagiven]

Just a thought, one more thing to check is the ebrake switch on the TT. Maybe the pull cable was partially pulled out and just tapping the brakes or bumps, is engaging the power through the switch for a moment.

Good luck,

[xtruckerbob]

I checked the trailer connector its not frayed. This is on a car trailer not our travel trailer so no break away brakes. The fact that it hits so hard even with the controller set as low as it will go makes me think it is a short. Tomorrow I will check the trailer.

[tnchuck100]

Up until now I thought we were referring to an RV trailer.

You found no frayed wire now we are back to the controller itself has most likely failed.

[xtruckerbob]

So Friday when I carried my tractor to the shop my in dash control was working when I push the lever to check the brakes... but hooked up our TT today and the in dash controller will not manual set the brakes. But when you press the brake pedal it does. So back to the shop.

[tnchuck100]

Now we are slowly getting more and more pertinent information.

1. Did the brakes work properly before you had the warranty work done?
2. Your last description sounds like someone hooked the brake lights to the trailer brake connection.

[xtruckerbob]

Yes they worked before. There has been no change in wiring.

[tnchuck100]

OK, let's see if I have all the facts straight here.
1. The car trailer brakes worked properly before the warranty work was done.
2. The car trailer has a 7-pin connector (not very common). No adapter is being used.
3. The travel trailer brakes also worked properly before the warranty work was done.
4. After the warranty work was done the car trailer would lock its brakes the instant the brake pedal is pressed.
5. The manual brake controller does not apply the brakes on neither the car trailer nor the travel trailer.

If I have all of the above facts correct then the truck (tractor?) wiring has been altered or the brake controller has a catastrophic failure. If I do not have the facts correct please provide any corrections.

Question: What was the scope of the warranty work?

[xtruckerbob]

tnchuck100 I think you are right, it is going back to the shop again.

[xtruckerbob]

Went back to the shop brake controller had a steady reading on 8.8 brake gain on the scan tool then went to zero (dash reads 1.1 brake gain while scan tool reads 8.8) so since it now reads zero gain they did not do any thing because they didn't find out what the problem was before it cleared itself, he said bring it back if it happens again. He worked on it for over an hour The good news no charge.