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.

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!

Ok, so this evening I checked every single fuse, circuit breaker and relay, all good. No malfunction light on. Voltage was 12.5 in the fuse panel. Turned key on  and had 12+ on on one pin at the round fuel  pump connector, and an even 3 volts on another. Looked in both tanks, pickup tubes seem in tact, cracked fuel line at the pump and there is fuel. Thinking it has to be something with ecm or pump electronics. When cranking it doesn’t even try to start, shoot it with either and it will run a few seconds. Not sure where to go from here, appreciate any suggestions. 

1995 RD688S E7-400. Shut off today, while driving. Seems to be a fuel problem as it will start and run on either. All accessories are coming on when turning key so ecm should be getting power. Thoughts on what to start with to trouble shoot? This engine is computer control but not an etec. Appreciate any suggestions!

Looking at a 2012 Granite Tri Axle Dump MP7 405 10 speed, air ride. Thoughts on this model year? What should I look for? Truck has been fleet maintained  250k miles.

I have a 95 RD688s with the 12 speed air shift. The extended range switch on the dash bleeds air when it's in direct. It's so bad we switch it into low in the am to allow it to air up. Everything works fine, I'm just wondering how to I determine if it's the switch or something causing air to bleed back? It is not leaking from the lines to the switch, its coming from the exhaust ports. I appreciate any suggestions.

On the grant swap out the stock mike if you still have it. There is a pin in the mike plug that has a "receive"wire if that wire is off the terminal or cut somewhere in the mike cord you will get no sound from the speaker.

I have a 95 rd with a 12 spd. The outside inversion valve is constantly leaking air from the botom of the valve, not from an air line or fitting(two bolted together on side of tranny, one closest to frame leaks)I replaced it and still acts the same. The only way to make it stop is if I flip the switch on the dash for low low, then i flip the switch back and the air leak is gone but will come back after driving.The transmission works fine, anyone have any ideas what's causing the air leak?

My truck leaks air when its not in the off position, and I cannot get air to blow out of my defrost when selected, however the Compressor does come on. If I change the "Mulit Position Air Switch" will my defrosters work? I do snow removal with this truck and it sucks to have no defrost!

On the VMAC 1 what would be the proper diagnostic prcedure? I feel I have eliminated the fan clutch, actuator on the side of the rad, and the ECM has been replaced (for another issue, however fan stayed on before & after)

I'm having a similar issue with my 95 E7 VMAC 1, I found this post useful however I still havent solved my issue. Bench tested the solonoid that stops the air to the fan and it works (Clicks when 12 volts applied). Fan clutch disengages when I disconnect the air line so I know it works. I tried the following procedure today to attempt to rule out ac high pressure switch:

With the air pressure up and the engine cold, I turned the key on, unplugged the high pressure switch and jumped connector with paper clip, nothing happened. I think the solonoid on the side of the radiator should have clicked if the high pressure switch is the problem? also tried the same method with the coolant temp senor,and nothing happened either. The ECM on the truck has been replaced and the fan was staying on prior to replacing. I looked for the fuse however my truck only goes to number 24, I guess since its older then the one in this thread.

I believe my coolant level sensor is in the water manifold towards the front of the truck, as there doesnt appear to be any wires going to the top tank (However I didnt climb up there and look at the back). Appreciate anyones suggestions on how to diagnose, fan belts keep stretching and squealing as a result of fan running all the time. I know I could easily install a manual switch on the fan, however the truck is in really good shape and I hate to bypass a factory system.

I noticed the Turbo on my 95 E7 400 is leaking oil in the center. Its a pretty decent oil leak, dripping down on the injection pump. Is this a sign of potential Turbo Failure? The leak is around where the oil fill tube connects to the Turbo below is I picture I pulled off the net to show where the leak is (its not my truck but the same setup). Truck has almost 450K on it, the turbo seems to have markings on it like it was engraved from a junkyard, I've owned the truck for about 18 months so I dont know the history. Last time I drove it it was putting out 30lbs of boost under load, I seem to recall it used to go up to 35. (I dont drive it that often)

Appreciate anyones thoughts!