anecdotal I know, but I've had the HB in mine that came from the factory (former) diesel and never had a problem with the PS or the HB until recently the PS pump seal let go (and I still have to fix it) ... no cooler, but I can't say I've ever tested the temps to see how hot it gets. Only thing I don't like about it is when the cars not running you're basically screwed, unless you almost literally stand on it. Otherwise it stops *now* with the HB.
This.
My dually apparently had a bad fuel level sensor when I 1st got it. I was exiting the highway to get gas since it was getting low & the engine dies on the exit ramp while still @ a pretty decent speed. I hit the brakes & absolutely NOTHING as far as assist. I'm dbl footing the brake pedal while simultaneously pissing myself as I roll through the light trying to stop the freakin' thing.
Scary doesn't describe it.
In the end, I learned the truck never should have passed the safety inspection as there were no rear brakes. As in
the brake shoe brackets were eating into the drums no brakes. At least w/vacuum assist, you have 1 or 2 additional stabs @ the pedal w/some help. The vacuum set-up I swapped to was cheap vs replacing everything the HB required; cleaner as far as the visual 'wants', & works just fine for my lighter duty needs (20' open car trailer w/a C10 swb truck as the max load). Unloaded, the vacuum assist locks up front & rears.