They may have forgotten OR since this such a new unit they have to contact Freightliner for an answer, that they may not have either.
Often times unintended consequences pop up when they design stuff. It happens with alot of things not just trucks.
It sounds like a malfunctioning tractor protection valve or something to that effect. Either that or it’s a new “safety” system. I wouldn’t be surprised if it’s designed to be that way but it’s definitely not safe. There should never be any system on the truck that interferes with operation of the brakes.
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I've been with Roehl for nearly two years now and just this past week I've been upgraded to a new truck - a 2025 Freightliner Cascadia. Sweet!
One issue I've come across though... Whenever I do a pre-trip, notably the alarm and button pop test, the truck enters a "Hold" mode and doesn't release air (or only in the smallest of increments) to the brakes. I have to sit there pumping the brakes like crazy for 3-5 minutes waiting for all the air to drain to ensure the alarms activate and the buttons pop. By the end of which my leg is seriously getting sore and starting to cramp. I'm pretty sure this is a new safety feature to prevent losing all your air, which sounds great on paper, but it sure makes doing the brake test portion of a pre-trip a right chore.
Is this what's going on? Is there a way around this? No matter if I pump the brakes slowly or quickly it always enters this "Hold" mode state. I've asked maintenance and they're baffled by it as well. So far the only way we've been able to bypass it is to leave the truck running and shift it into gear, then pump the brakes and whenever it enters the "Hold" mode then push the accelerator which deactivates "Hold" and then continue pumping the brakes before it locks up again. Back and forth. This is of course not ideal as that's not how you're supposed to properly do the brake test, and while the truck is running it's building up air pressure which defeats the purpose of the alarm and button pop test, but it's all we've come up with so far. The maintenance guy said he'd get back with me when he finds an answer, but so far it's been several days and no word (he may have forgotten).
Thoughts?
Baffle:
A partition or separator within a liquid tank, used to inhibit the flow of fluids within the tank. During acceleration, turning, and braking, a large liquid-filled tank may produce unexpected forces on the vehicle due to the inertia of liquids.