Service Brakes w/ Retader, Panic Stopping

[davidbrady]

Hi Joe,

Great to see you on the site, welcome, and thanks for your input!

Attached is a paper that says a fully loaded school bus, loaded to GVWR can lock it's tires on all axles. It also shows that the school bus outperforms the braking performance of a class 8 truck, also loaded to GVWR. I think this is the crux of the question: if the service brakes are powerful enough to engage the ABS on a high grip dry surface, then any additional stopping power injected by a retarder (whether transmission or jake) won't improve stopping distances and may actually lengthen stopping distances because the ABS can't correct for the retarder. I've never done it, but my opinion, FWIW, is that a modern disc brake equipped Prevost motorhome conversion can lock its wheels on a dry high grip surface. If true, then there's no need to waste time flipping switches when braking in an emergency situation. Just stand on the pedal!