EWB555

Thanks guys, had a bottle with new sensor at the shop luckily. Changed it the next day no more issue. Funny how things work sometimes, no issues until it legitimately ran low on coolant.

Had a coolant line blow today on a 2016 granite, dumped several gallons out. Was able to get the hose, refill with about 8 gallons of coolant, its full to the max line however low coolant/stop engine light won't go off. Drove the thing loaded with 70K about 8 miles back to the shop after replacing and filling coolant, never got past 195 degrees. Unfortunately, its clearly in power derate, wouldn't go over 45. Any thoughts on what I should check?

The silver solenoid in the lower left of your fuse panel have you checked it? I have a 95 Mack, sometimes it would crank and not start-that big solenoid is what powers the ECM, If you turn the key on and dont here the big click inside the dash-check that. Also check the wiring for bad connections, these older trucks there is no telling what it could be. I chased headlights not working for weeks, then finally pulled apart some connectors under the dash for the harness, cleaned the terminals and good to go.. Good luck and let us know what the fix is if you figure it out.

I really appreciate your response. Been a while since i had a chance to look at the truck myself (Its my Dads, I just Help him out on weekends). So this blowby tube just goes directly to the side of the valve cover, there is no device in line. I know what your talking about though as his 2016 Mack with an MP7 has one. This truck is an 07 with what i believe is an EPA 06 MP7 (It has EGR for sure) We changed the oil this evening, and i did observe that the oil fill tube connects to the pan right next to the blowby tube, its rubber/plastic and I cant 100% rule out that the oil thats blowing down the side of the motor and all up under the frame is coming from there. Maybe wishful thinking but I cleaned it up and we are going to keep an eye on it. Also questioning that maybe we arent being given the correct oil filters for the truck? Any time i have been in to pick them up, its always individual filters, Mack doesnt make a Kit, and that truck is kind of an in between as its an 07 CTP with the MP7, a lot of 07's were the CV model with the AMI engine. The only reason I am saying this is becasue if we know the oil is good per the sample when we change it, the only other thing that could be affecting the oil pressure is the filters. The problem we are having run 8-10K miles, truck starts shutting down for low oil pressure on long pulls, change oil & filters, good for another 8-10K. We pulled another oil sample to send out. Other then that kind of at a loss. Just still struggling to believe this thing needs an overhaul at 171K miles, especially seeing how the last oil sample came back, without coolant, excessive wear metals, or fuel dilution. Any thoughts are always appreciated.

@Mack Technician-can you elaborate more on how blowby will affect the centrimax filter? Have an 07 CTP Granite with an EPA 06 MP7. Truck has 160xxx miles, and its blowing oil out the blowby tube. Also can only get 8-10K miles out of an oil change before it cuts out flagging low oil pressure (we are topping off, using probably 1 gal/week). Sent the last oil out for sample, all normal, no coolant, not high fuel dilution, and still in vis range for a 1540. So got me thinking, not the oil causing low oil pressure, but the filters, since they are changed every time, then good for another 8-10K miles. Is this engine needing a rebuild? Truck pulls strong, just struggling to believe its time to tear down with such low mileage, and reasonable hours. Appreciate any thoughts you have.

I figured it out and wanted to share. There is a body builder connector under the back of the cab on the drivers side. Fortunately they put a label above it on the back of the cab that tells you what each pin is. On our truck only the stop, run, &turn lamps are wired. Ordered the deutch socket online for that particular connector and was able to wire my stobes to one switch, and the plow lights to the other. You crimp the socket to your wire and slide it in to the blank slot across from the corresponding pin. It’s a nice setup. I attached a screenshot of the socket part info and pictures of what the connector looks like in case anybody needs them.

Can someone please tell me where to tie into the circuits for the key on and battery accessory switches on a 2016 Granite dump truck? Pulled the entire dash apart last week and cannot find the leads.

Problem solved. Must have missed a fuse when checking. After spending the day yesterday troubleshooting from a schematic that I was told was my trucks, (it became apparent that it was similar, but not the same as mine as I was troubleshooting) I was able to pull the fuse box info from this site for a 96 Mack. Checked my truck today, fuse 16 for turn signals blown, replaced, left turn worked fine, right turn. 3 blinks then pop, blew fuse. Unplugged front end harness from near passengers side firewall, replaced fuse same result, (ok short is not in front harness). Plugged back in, replaced fuse, hooked up new turn signal switch, left turn ok, right turn -good to go. Short must have been in the signal stat all along. Shame on me for missing the blown fuse the first time!

My truck is a 95, fuse 16 is for turn signals. not sure what problem you are Having, I had a short that blew the fuse, ended up being the turn signal switch.

Currently have no directionals front or rear, and no brake lights. Checked fuses all good, plugged in brand new turn signal switch, no change. Tested in fuse box, no hot to the flasher. Schematic shows fuse feeds the flasher which feeds the circuit,Could my panel be shot? Appreciate any ideas. It's odd to loose both at once.

Took the truck for MD inspection today...In the last few weeks we replaced the flex under the cab, put a muffler on it (it had a straight pipe) changed the front and drop axle tires, fixed the air leaks (2 fittings) Outside of inspection items I wired it for an electric salt spreader, installed plow lights, strobes on the rear of the dump bed, beacon light, our welder set it up to hang the spreader on the back, made a box to mount the plow pump on the frame, and installed a steal bumper to hold the plow frame. Also ran a new CB coax through the dash/door and put to the mirror bracket. Oh, and apparently NY spec keeps the drop axle switch on the outside of the truck?! Had to relocate the switch to the dash. It’s a steerable axle however need to control it from in the cab. After all that inspection found left turn signal on the driver side under the cab not working (dad says it was when he checked) they say it has a crack in the windshield which baffles me because I had my head all up in the dash taking it apart to run the CB coax, and the kicker- they say the manifold is leaking on the back cylinder. I have not seen it but dad says it’s extremely minor. I did note how far back into the cab this engine sits compared to our RD. Does anyone have thoughts on how bad of a job it is to change manifold gaskets on an early MP7? Appreciate any info!

My dad and I picked up a 2007 Granite MP7 405 Tri Axle dump from auction this week. Truck only has 112k & 6xxx hours. Cab& chassis are in great shape, ox steel body is beat to hell. Curious on everyone's thoughts about the early MP7 engines? What do we need to be aware of? Truck sounds and runs good. Only issues I can find are a minor air leak under cab, and the small gauges on the dash are broken off from the bezel and have fallen back a little. It has the Mack 10 speed trans. So far pretty happy with it from what we see. We have owned 3 R models over the years 78,86.& 95 (still have the 95) and they have consistently been the most reliable trucks. Hopefully this Granite will live up to the Mack reputation.

Been a while since I posted this. Call me crazy but as soon as temperatures went up during spring & summer this air leak went away. Now here we are in December and it's back again, I replaced the switch today and that was not the problem. I moved the switch on the shifter and that did I not seem to change the air bleed from the dash. The only thing I did realize is that when I switch to low, the leak doesn't go away, it moves to a union in the air line down under the cab. Isnt the inversion valve what steps down the air pressure? Maybe it's letting too much air to my dash switch.

Figured it out. Should have known that when I cracked the fuel line at the pump and some fuel dribbled out that didn't necessary mean it was getting fuel to the pump. First thing I did today was pull the filters, neither one was full. Put 2 new ones on full of fuel, hit the primer on the new transfer pump until it was hard to pump, and it fired up after about 5 seconds. Let idle hoping that maybe it actually was the transfer pump and it just needed a good prime, but I had a feeling that wasn't it. Anyway after a few min I could tell the idle had changed and it was clearly not right, hopped in the cab gave it some fuel to confirm it was missing then shut it off. Disconnected the main line from the primary fuel filter, slid under the truck and stared tracing it, when I got to the back of the trans where it crosses over I discovered that it had a hole in it from rubbing on something. Pulled the line off the truck and will have a new one made tomorrow. Thankful it's not an electrical gremlin however frustrated that I didn't pull the filters when I first checked the truck out last week.

Well, we know it's not the fuel transfer pump. Dad talked to a mechanic who suggested we try that, he picked one up and put it on today, nothing changed. I am going to mess with it Sunday, it's going to rain here all day Saturday. We didn't want to put the truck in our shop since it's loaded. Will definitely crack one of 6 lines on the pump and see what we have. From there I'm going to start checking wires in the harness. Does anyone know how to check the sensor in the side of the pump or the one in the flywheel housing? Will these make it not run if they fail? I have a multimeter and can check voltage, resistance etc. Just not sure what I need to look for. I do appreciate everyone who has chimed in with suggestions!