Out of Service South of Williston: The Scale House Found What the Pre-Trip Didn't

Instead, the four-axle combination was placed Out of Service at the scale house.

The driver was hauling products needed for the tank battery installation. Now the driver, trailer and load were sitting while repairs had to be figured out.

What makes this one worth talking about is both what should have been caught during a pre-trip, and how the scale house found a brake problem without ever getting underneath the trailer.

Some Problems Were in Plain Sight

According to what we were told, a proper pre-trip hadn't been performed.

The truck was missing a fire extinguisher and warning triangles.

One trailer tire was at approximately 20 PSI when it called for 110 PSI, and there was a screw visibly stuck in the tire.

That isn't a complicated diagnostic problem. A walk-around should have caught it.

But the brake issue was different.

They Tested All Four Axles, One at a Time

The scale house used a Performance Based Brake Tester, or PBBT.

This hotshot combination had four axles:

• Truck front axle
• Truck rear axle
• Trailer front axle
• Trailer rear axle

They pull one axle onto the machine at a time, apply the brakes, and the tester measures the actual braking force being produced at the left and right wheel ends.

Then they move ahead and test the next axle.

After all four axles are tested, the system compares the total braking force against the actual weight of the truck, trailer and cargo.

For this type of commercial combination, the required braking efficiency is 43.5%.

For example, a 30,000-pound loaded hotshot combination would need to produce at least:

30,000 × 43.5% = 13,050 pounds of braking force

The machine isn't simply asking:

"Does it stop?"

It is measuring:

"Are the truck and trailer producing enough braking force for the weight they're carrying?"

That matters because the truck can feel like it stops fine while the trailer brakes are doing very little. The truck may simply be doing most of the stopping.

The Machine Found the Problem. We Found the Why.

Here's the interesting part:

The inspectors never got underneath this trailer.

The PBBT told them the combination had a braking-performance problem.

When Mondak Equipment got underneath the trailer and physically inspected it, we found additional problems the scale-house inspection hadn't identified:

• A leaking wheel seal
• Electric trailer brake linings worn down to approximately 1/4 inch

The PBBT identified that the braking performance wasn't there.

Our inspection started identifying why.

And that's an important lesson for hotshot operators. Electric trailer brakes still have shoes, magnets, drums, wiring, wheel seals, hubs and bearings that wear and fail just like other equipment.

You may feel the trailer brakes working from the cab.

That doesn't mean every wheel is doing its share.

Hotshot Trailers Need Maintenance Too

Hotshot trailers work hard around the Bakken hauling oilfield products, equipment and materials.

But the trailer often doesn't get the same attention as the truck pulling it.

That's how a leaking wheel seal goes unnoticed.

That's how brake linings wear down.

That's how a tire ends up at 20 PSI with a screw in it.

Eventually somebody finds the problem.

It's a lot cheaper when that somebody is your mechanic instead of the scale house.

Mondak Works on Hotshot Trailers

At Mondak Equipment, we repair and maintain hotshot and commercial trailers and perform DOT inspections designed to catch these problems before the equipment is loaded and headed down the highway.

• Electric trailer brakes
• Wheel seals
• Hubs & bearings
• Brake wiring & controllers
• Suspension
• Lighting
• Structural repairs
• Preventative maintenance
• DOT inspections

Today, this load was supposed to be arriving at a tank battery installation.

Instead, the hotshot, trailer, driver and cargo were sitting south of Williston.

Find the problem before the scale house does.