Service Brakes w/ Retader, Panic Stopping

[davidbrady]

Guys,

There are folks on another forum who claim that those of us with retarders, whether hydraulic transmission, jacobs brake, or both, should always leave them enabled so as to shorten our stopping distances in full on panic braking.

I've never succumbed to this belief so I thought I'd ask this group. The Prevost literature corroborates what I've always thought was true and that's that retarders are for downhill braking, and downhill speeds should be reduced such that the retarder alone can maintain the desired downhill speed. This approach keeps the service brakes cool and on standby for emergency braking.

Nowhere in the Prevost owners or drivers manuals do I see anything alluding to the idea that panic braking in a Prevost is only achieved to it's full power when the service brakes are applied with the retarder(s) enabled. It seems to me that the service brakes alone should be sufficient to achieve maximum braking power and minimum stopping distances during 100% brake pedal application.

I guess what I'm saying is that surely the service brakes are powerful enough to lock up the wheels on all the axles. I've never had to do this but I'm sure it's true for the tag and steer axles. That leaves the drive axle. Are the Knorr-Bremse Prevost drive axle disk brakes powerful enough to overcome the drive axle tire grip or can more braking power be attained by adding retarder braking on the drive wheels?

I routinely drive with the retarders disabled at the dash. I find it's easier to maintain transmission fluid temps when I'm in control of when the retarder is activated. With a Jake I find it's easier to pick up momentum on downhills if I wish to let momentum shave a tenth or so off fuel consumption on the uphills with the jake disabled.

Thoughts?