[Windwalker]

Think about the physics of it.

Using the jake puts a drag only on the drives. The rest of the weight is still pushing you forward. Once the drives break traction, how much weight and inertia do you have trying to maintain the same speed or speed you up? Theoretically, (if your brakes are properly set up) by using the brakes, you are distributing the drag throughout the vehicle.

Some years back, I was on I-70 in CO. On the east-bound side, when I came out of the tunnel, there was a truck that had jack-knifed going down the hill. We all came to a stop and when I set the brakes, I only set the brakes on the tractor in case the trailer brakes might freeze up. I quickly discovered that the tractor was starting to slide forward. The only way I could stand still was to set the trailer brakes as well. Now, that is: FROM A STANDING STOP, SET THE TRACTOR BRAKE AND RELEASE THE PEDDLE, AND START TO SLIDE FORWARD.

Now, translate that into the jake. If you can get into serious trouble by applying too much power to the drives, you can also get into very serious trouble by applying too much brake to the drives.

[Mack2]

Originally Posted by golfhobo

Fredog said:

Not sure what "sticker" you refer to, but from the manual page that Splitshifter posted, if you read carefully, you'll see that pulling the yellow knob, sets the tractor brakes AND the trailer emergency brakes but ONLY because (as we all know) if you pull the yellow knob without holding your thumb on the red valve..... it, TOO will pop out!

If you hold the red knob in, while pulling the yellow, you are setting ONLY the tractor brakes.

The manual ALSO says, that if the air pressure drops to the critical level, the yellow knob activates, and again..... just as I stated above, the red will pop out TOO!

The wording is confusing, because it assumes activation of the yellow knob by itself with no Driver Control over the red knob.

Very simply.... yellow=tractor, red=trailer. The blue knob was for a MANUAL (not air pressure balanced) application of the tractor brakes to be used temporarily while starting the OLDER trucks.

Golfhobo would you care to explain then why our 1999 Mack lowboy tractor has that third valve.

[golfhobo]

Originally Posted by Mack2

Golfhobo would you care to explain then why our 1999 Mack lowboy tractor has that third valve.

Not without reading the manual for, or seeing your truck. But, I can READ the page that was posted earlier (even tho it's fuzzy) and that is pretty much word for word what it said (combined with something another poster mentioned about the older trucks.) :lol:

[FIRST post from the Hobo while on the road!! This is KEWL!]

[Ridge Runner]

[quote="golfhobo"]

Originally Posted by Mack2

Golfhobo would you care to explain then why our 1999 Mack lowboy tractor has that third valve.

Not without reading the manual for, or seeing your truck. But, I can READ the page that was posted earlier (even tho it's fuzzy) and that is pretty much word for word what it said (combined with something another poster mentioned about the older trucks.) :lol:

[FIRST post from the Hobo while on the road!! This is KEWL!][/quote]

It was bad enough we ( moderators ) had to worry when you were home, now it's going to be 24/7 :shock: I'm going to have to have more money!
:lol:

[golfhobo]

Not to worry, Ridge! I haven't bought a laptop yet, and of course, I can't get on from ANY truckstop in the country... since they've ALL been banned... but I'm at a motel this weekend due to circumstances beyond my control, and using the "access puter" in the lobby! Of course... i do stay here from time to time! :lol: :lol:

[Ridge Runner]

Whew!!! I thought maybe you had up-graded to the 21st century. :lol:

[golfhobo]

Originally Posted by Ridge Runner

Whew!!! I thought maybe you had up-graded to the 21st century. :lol:

Time a'comin!! I saw an ad for a used laptop tonight for about 3 bills! That's getting CLOSE to my allowance! :lol:

Of COURSE I'm gonna join the new century!! But, by then it may be the 22nd! :wink: