Mikesbucketlistmack

I'm contemplating changing the coolant conditioner on my 1981 R612. I've had the truck over 10 years and barely drive it 50 miles per year. It has only 65,000 miles on it. Do you think the coolant conditioner should be changed and if I take it off while the truck is off will I get a bath of antifreeze ? Thanks !

Terry, I can't see a picture of the mirrors, but are you talking about the ones with the half bulldogs on them in the front ?

I think we ALL got it. Did she ask you how's your Peter-bilt ?

Try Utica Mack in Utica , NY. I've never had a problem with them.

Okay, Jim. I'll try all those. I couldn't find any other fuses so hopefully that won't be an issue though it would be an easy fix. Thanks, Mike

The switch I took out was "short", and I replaced it with one the exactly same size.

Hi Gents ! I got a 1981 single axle R 600 dump with back up light/alarm issues that is causing me to pull my hair out (the little I got left 😲) trying to get them to work. They worked fine since I've owned the truck the past several years. About a month ago they stopped working. I found that the ground wire at the rear of the truck had come loose. I reconnected it and the worked again. The next time I took the truck out they stopped working again. I rechecked the ground wire and it was fine. I pulled the fuse in the glove compartment and tested it with a continuity tester and it was good. I then checked the back up switch on top of the transmission. The terminals were all corroded so I replaced it with a brand new one. I tried the lights /alarm again and they worked for a second and then stopped. I checked all the wiring at the rear of the truck and at the 3rd terminal under the driver's side of the hood and all connections are firm and good. Does anyone have any ideas or am I missing another fuse or something else ? Any help would be appreciated because I can't get it inspected without the lights and alarm working. Thanks !

Okay, thanks. That's what i was thinking, too. I'm going to try that and let you know.

What exactly am I looking for with the ohmmeter and to which terminals do I attach the leads ?

Check any big city's Post Office Vehicle Maintenance facility near you. They will direct you to where they do sell the used ones off at times. I used to drive for them in the 90s. I had a brand new single axle MR, automatic. They special ordered them WITHOUT air conditioning or radios. They were pretty good with a trailer on but don't ever bob tail one in the rain. They were also terrible on snow and ice. I don't know if there are any more Mack MRs out there. I think that they have gone to all conventionals now or are just renting tractors from Ryder.

Thanks, Ron. I finally got some time and disovered that a strange looking unlabeled button on the dash works the city horn. Someone must have reconnected it when the steering wheel button failed a long time ago.

On my 1980 R611ST, it looks like someone disconnected the engine block heater wires. I want to reconnect them but which terminals do the black (hot) and white (neutral) AC wires go to ? It looks like the green (ground) gets connected to the bottom screw. And what gauge wire should I use ? Thanks, guys !

I'm trying to get the steering wheel horn in my 80 R 611 ST working. It looks like it's been disconnected as there is a black wire with a push in end hanging out of the steering column (see picture). I checked under the dash for the other end of a wire that might have been connected to it but there are no loose wires. I checked the horns by running a wire from them to the battery and they work. I followed the horn wires all the way to the horn relay in the glove box and there are no breaks. Any ideas where this wire from the steering column should be connected to ? What would happen if I connected it to an empty terminal of a power block under the hood ?

Try Global Truck Traders in Winchester, NH. They are always dismantling old Macks and have a ton of old parts in their warehouses. You can find them on globaltrucktraders.com. They're very busy and never get back to you by phone so usually it's best just to go up there and walk through their place and find what you want. Also, the best Mack dealer I've found to get new and old parts is Utica Mack in Utica, New York. Call them at (315) 797-1714 . Ask for Dan Kiss. He's gotten me plenty old parts for my 1980 R 600 and ships out in one day.

Okay, thanks. I was thinking of the one in Ballston Spa. The only problem is that my truck is geared so low that the top speed is only 53 mph ! I don't want to be a hazard on the road if I have to take any interstate highways to get there like I-87 !

Does anyone know where one can find out about trucks shows in the New England or upstate New York area ? Thanks !

Hi Justin ! If you're still looking for gauges I bet that Global might have some old ones. Mike

Yeah, it used to be a municipal truck that never went out on the highway so they probably didn't need the speed.

Anyone needing parts for their Macks contact Dan Kiss at Utica, New York, Mack dealership. Phone number 1-315-797-1714. E mail is dkiss@umack.com. He gets right back to you and can find parts for newer trucks as well as old ones like mine. Tell him I referred you.

I got one at the Utica, New York dealership. They're the best place around to get parts. Ask for Dan Kiss.

The R models have always been my favorite, too. Yours came out very nice ! Too bad it had to rain on it and get it all wet

Thanks for the good answers, guys. I forgot about the screen on the pickup tube.

Wow, I wish mine was like that. I get a top speed of 53 MPH in the top 6th gear (overdrive) at 2100 RPM !