Trailer Brake

So how do you test your trailer brakes without it?

So how do you test your trailer brakes without it?

Trailer brake set (red knob out), release tractor brake (yellow knob in), then do a couple tug tests.

So how do you test your trailer brakes without it?

Trailer brake set (red knob out), release tractor brake (yellow knob in), then do a couple tug tests.

The trailer ("Trolley" or "hand") brake lever controls the trailer's service brakes. The red "Trailer Air Supply" valve runs the trailer's spring/parking brakes. So the basic tug test only checks the trailer parking brakes.

Here's a question from the CDL General Knowledge test bank:

Q. When should you use the hand valve to park a combination vehicle?
    a. To park at loading docks.
    b. To park on a grade.
    c. To park for less than two hours.
    d, Never.

The correct answer: "d." I tell students in class the best use for that lever is, as noted, a place to hang your sunglasses.

I recently used mine coming down a steep hill in a blizzard with a load of gravel. Truck started jackknifing because I had the engine braking still set on high (blizzard came on quick). Handily straightened the rig right out. Gotta use a delicate touch, though, they'll lock the trailer wheels up pretty easy. Anyway, glad to have it available.

I asked my trainer last night since we don’t have it on our truck how do you check the brake lights on a trailer alone? I was taught many years ago to depress trailer parking brake, pull down the trolley bar, and walk back to ensure brake lights are working.

His answer: a chuckle and he reaches behind the seat and pulls out a small oak tree branch with a Y on one end that he cut long enough to put the Y on a cross bar of the seat and the flat ends depressed the brake pedal.

That my friends is just one item of what 35 years of driving experience will teach me. I think it falls under the category of “a truck driver always has to think on his toes and overcome obstacles on his own!”

I asked my trainer last night since we don’t have it on our truck how do you check the brake lights on a trailer alone? I was taught many years ago to depress trailer parking brake, pull down the trolley bar, and walk back to ensure brake lights are working.

His answer: a chuckle and he reaches behind the seat and pulls out a small oak tree branch with a Y on one end that he cut long enough to put the Y on a cross bar of the seat and the flat ends depressed the brake pedal.

That my friends is just one item of what 35 years of driving experience will teach me. I think it falls under the category of “a truck driver always has to think on his toes and overcome obstacles on his own!”

My International has a light test button. I turn it on during pretrip and it cycles all the outside lights continuously until turned off.

Our trucks dont have the trolley brake levers either.

Rick C wrote:

I recently used mine coming down a steep hill in a blizzard with a load of gravel. Truck started jackknifing because I had the engine braking still set on high (blizzard came on quick). Handily straightened the rig right out. Gotta use a delicate touch, though, they'll lock the trailer wheels up pretty easy. Anyway, glad to have it available.

The purpose of the trolley brake is not intended for what you claimed to have used it for. How is it you had the presence of mind to pull the trolley brake but not kill your Jake Brake?

Every technical document, DMV CDL manuals and instructor courses emphatically recommend not using it as a service brake while the truck is moving.

Very dangerous what you did. Please do not advise anyone to use the trolley brake for anything other than testing your trailer brakes or holding your tandems while sliding them.

If in fact your story is true, 99 times out of 100 your trailer brakes will lock, causing an already bad situation to get worse.

I recently used mine coming down a steep hill in a blizzard with a load of gravel. Truck started jackknifing because I had the engine braking still set on high (blizzard came on quick). Handily straightened the rig right out. Gotta use a delicate touch, though, they'll lock the trailer wheels up pretty easy. Anyway, glad to have it available.

Now THAT'S a trucker story if I ever heard one!!! It's a long way from being in the Hall of Fame, but a good one nonetheless.

A rookie driver going down a mountain loaded heavy in a blizzard has the presence of mind, quickness, and delicate touch to prevent an ongoing tractor jackknife by easing on the trolley brake just in the nick of time?

That's a fantasy scenario you dreamed up in your head, friend. Sounded great, though. If you were that good, the Jakes wouldn't have been on full blast in that scenario in the first place. Instead of hitting the trolley bar you would have gotten on the throttle which would have shut off the Jakes and helped you accelerate out of the slide at the same time.

Great story, though. Went good with my coffee.

That's one of those "Ice Road Trucker" tales. Rookies believe them. Veterans know much better.

That's one of those "Ice Road Trucker" tales. Rookies believe them. Veterans know much better.

Yah think? I rewrote my reply three times in order to reduce the snarkiness... “a kinder, gentler G-town”.

Looking forward to reading a really juicy reply from Rick.