Tractor parking brake doesn't hold 44K load on steep on-ramp

Who the hell specs a truck with only 1 axle's worth of park brakes? I've worked on a TON of trucks and every one of them had park brakes on every drive axle.

 

Werner.
The truck also doesn't have inter locks.
It WAS an otr truck.

 

All the Freightliner’s I’ve seen only have them on 1 drive axle. Common thing. Mine does that now, I don’t need to check the spring, I know it’s broken. Saw an old Volvo roll off the fuel island into a brand new Peterbilt once. The Guy with the Pete wasn’t happy about it. What are the chances? It was painful to watch

 

@spsauerland posted an interesting tidbit in another thread today. On Kenworth, the tandem capacity is derated to 36,000 lbs if spring brakes are only on one drive axle. Probably explains why I've never seen it. Everything out this way is 46k

 

I'll have to see what the w900 I drive says.

It has a drop axle. The tridem is good for 43,500

 

I refuse to believe that trucking is built with #### brakes that wont hold on any grade or surface....

 

one or more of your brake assemblys has either BAd s-cam bushings and or bad slack adjusters. When you have a bad s-cam pushing, the whole s-cam torques out to either side and you wont get the full hold and you will also notice the brake pads wearing unevenly. I used to have same issue as you and noticed all hell breaking loose back there in the tandem area, Im a perfectionist. So i spent a weekend and changed out all the s-cam bushings and slack adjusters. 2 of them werent holdig adjustment. Now, you cant move the truck if you tried to with the parking breaks on. Yeah its possible some of the old slack adjusters still had some life yet but why wait. Swap them all out along with cam bushings

 

Go stateside and take a gander where there are many parked trucks in one spot. You will have your answer in no time.

 

Negative. Good operating brake system will have no problem holding weight on the slope. Has bad components somewhere

 

Negatory. One pair of maxis on one axle will not hold 80,000# on much of an incline. It is called physics. Even 2 axles won’t hold 80,000 lbs on a steep grade.

Three or four axles with maxis will hold 80,000# or more on a fairly steep grade. Again it is all about physics.