Smoothy

I have read other posts here in the past that mentioned welding up the end up of the auxiliary stick and grinding it back to factory shape. After so long the rod rounds off at the end causing the shifter to hang up or pop out of the gate without completing the shift. I have the same issue with the quadruplex in my B. It jumps out of the gates usually when crossing over the H pattern from LL-Lo to Dir-Hi. I'm not sure that the same applies to the Duplex, but this is what I've heard.

Yeah I'm not exactly sure what's going on with this thing. The plastic line coming off the fitting in the manifold is just dangling off not attached to anything and the puff limiter line from the injection pump that goes to the reverse relay is also removed. It seems the puff limiter has been disabled, but they didn't clean up their work. Wondering if I should just finish it off and cap the lines to the manifold and maxi brakes. I can't imagine the reverse relay is doing anything at the moment.

Well, it took some digging. But this problem was one I invented. Thanks again, BMT forums.

Thanks Mark, that makes perfect sense to me now. I've managed to scrounge up the Mack service manual on puff limiters from another thread on the site. What I don't understand now is that if the reverse relay leaking/ bleeding air off into the atmosphere with the brakes released is normal, surely not right? There's no figure showing the different ports on the reverse relay, but it does mention a test port. Is that what is leaking on my relay and simply needs plugged? The only other thing messing with my head on this one is that the control valve appears to be removed.

This is actually on my 77 R model, but regardless who knows who has messed with what. It's not an air can leak as it is leaking directly out of the plastic piece with the arrow pointing to it.

It must be associated with the parking brake system. I had the brakes released on the truck to check slack adjusters and when I pulled the knob to set the brakes it quit leaking.

Here's a pic of the braided line.

Looks like the braided line runs into the intake manifold and the other tees into a pair of lines running into the cab and under the dash.

What exactly is this thing? It seems I've developed my first air leak on the new R. Its leaking air out of the jet looking looking orifice under the 90° fitting. Not sure where to go from here.

Got a couple of things done today on the R model. Got the clutch adjusted and it sure made a big difference on how the truck shifts. Thanks again Paul for the video from EZ. Also got the build sheet and rest of the papers from the Mack Museum. What a neat service they've got. The truck hasn't been changed too much through the years, other than of course converted from tractor to dump. It's not nearly as heavily built as my B61, but it's sure earning its keep. Looks like it was built in Canada and sold through the Mack dealer in Terre Haute. It was spec'd and ordered by Solar Sources, a mining outfit in Indiana. Kinda neat that it came back to a mining family.

CL75 is a Spicer 14" ceramic 2 plate unit. My 77 came spec'd with one too.

Thanks, Paul! I'll check it out once I get it back home. Got my first job with it hauling a few loads on an inground swimming pool removal. It's just an on site job, but I'm happy to have the chance to run it.

I stand corrected. The Chevy is a 68 C70. Anyhow, I spent a day working on the R model yesterday. I thought I had tracked down an engine oil seep coming from the oil fill. After removing and replacing the gasket I think it might be coming from one of the plates on the side of the block behind the injection pump. Looks like a challenge. I also need to figure out what the clutch adjustment procedure is to determine whether I have a worn clutch or poor adjustment. Its not slipping, just engaging pretty high up towards the top of pedal travel. The cable/linkage setup is unlike any I've ever fooled with, aka never a big truck.

Thanks, Paul. We just call it generational hoarding.

Yes, the black tandem dump is a Chevy. I think its a C90, which is, according to my quick google search, the same thing as a GMC 9500. There's also a 9500 GMC Short Hood at the farm that's a tandem tractor. The black one has a 3208 and twin sticks, the tractor is an 8v-71 13 speed. The old GMs are neat in their own way. I wouldn't mind having a few more runners around.