Seen these in some older trucks, mostly in movies :lol: Came across this pic and thought I'd ask here. My guess is it has something to do with old trailers that didn't have spring brakes?

 

i dunno what it is for but i can tell ya that an old MACK :wink:

 

The blue knob is for releasing the spring brakes on the truck so you can move it off the road or a little way to get it to a safer spot. This valve is fed from its own air tank. It is spring loaded and you have to hold it in to keep the brakes released. This is something not used any longer! (pre 1975) this is when the spring brakes were on the tractor only and not the trailer.

 

Gold star for mackman, nice! Not just any bulldog, but a cabover! Respect. It was an interior shot of this one, recently sold on ebay.

 

Thanks Fozzy, I knew someone here would know. Pretty weird feature, but I guess it makes sense. I had googled it a while back but didn't come up with anything, no wonder.

 

That truck would make my father homesick. That was what he drove for YEARS. He also drove R model Mack's hauling Harvestor silos on a dedicated contract to the Amish in Lancaster PA.

 

I drove one like that in Trucking school.. it sucked almost as bad as an "R" model Mack.. but not quite. :lol:

 

Man, I wanna try driving an R model! I almost had my chance recently, one of our guys borrowed one from another terminal and it had to go back. I told dispatch repeatedly I wanted to do it, and they said when the time came I'd be the man (they thought I was nuts, of course). I actually asked if I could use it on my run for a day, but they didn't want to risk me breaking down (I doubt it would have anyway). Well wouldn't you know, I come in one day and it was gone, they let someone else take it :roll: When I was a kid, and I thought of a Mack, an R (or U) model was what came to mind. Just wanted to experience one for myself, I'm nostalgic like that.

 

Those R Models were tough. Rough ridin, too. :P

Good transmissions. :|

One stick for 1-5, and the other for Low, Direct, and Reverse.

The outfit that do part-time farm work for have 2 R Models. When I driving, I just leave it in Direct, and just make her smoke. :P Heaven forbid if I ever have to back up, and try to get it in Reverse. :P

 

I drove an R model for like a year with the same tranny JR said it was a good truck the best is shifting in reverse. I love them older macks just somethin about them The U model is a ugly SOB.