Mackpro
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There is a new updated pipe number 21599120, also on that pipe it takes 2 o-rings on each end of the pipe.
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Being a tooth off on the cam gear will set the cam position sensor code. I’ve done more than once , especially on the MP7 where they have timing marks on the front and rear of camshaft. The marks on the front of the cam are not inline with the rear of camshaft. So always remember on the MP7 to use the rear camshaft marks for timing. Luckily on your MP8 it only has timing marks on the front of camk
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2015 mack pinnacle no crank no start
Mackpro replied to mackrmodel686st's topic in Electrical, Electronics and Lighting
I found my notes on this exact problem, “No power till you turn key to start position “. Fuse/breaker number 7 in top dash fuse box is bad or blown. The one I had used a fuse and showed 12 volts on both sides( key off) but when turn key to on position one side of the fuse dropped to 2 volts -
2015 mack pinnacle no crank no start
Mackpro replied to mackrmodel686st's topic in Electrical, Electronics and Lighting
There is a ground stud welded to the frame rail behind the battery box. Check the wire from the ground stud to the negative on the battery. It’s a smaller fuseable link wire that can melt inside and cause this issue. I’ve also had the stud break loose from the frame and had the eyelet ends come looked from the cables -
There was a design change around your year model. The original MP8 side cover had a grove machined into it and a rubber sealing strip that went into the grove to form a seal/gasket. They updated the side cover to a smooth surface with a metal gasket with rubber seal made on the gasket. I remember replacing the whole side cover to get the new style cover/gasket because the old string rubber seal was discontinued.
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On some trucks we saw the starter solinoid shorting internally and making the engine die in a hard pull when the engine would lean over.
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Here is a bulletin on this. https://static.nhtsa.gov/odi/tsbs/2018/MC-10152929-9999.pdf
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“No Info” message on the cluster on thoses years is usually the J1708 or J1939 data link wires shorting in the engine harness. Had 2 in one week doing this and it was shorting wires in the engine harness behind the oil filters . New engine harness solved both theses trucks. Also check the engine ECM connectors for rotted pins due to antifreeze in the engine harness.
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The oil leaks are probably the bottom exhaust manifold studs. They are drilled into the oil return/push tube area and you have to put RVT silicone on the studs if oil is seeping around then . This is only on the bottom studs. Using to long of bolts or the incorrect studs can actually hit the push tubes and cause issues
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Going through my notes, not long ago I had a 460 CHN with low power complaint. New injectors, good fuel pressure, turbo actuator adjusted to 37 psi of boost , newest software. All perfect and ran great with no trailer. We wanted to replace the fan clutch because it was stuck on but owner declined . Finally he gave us the OK and once we replaced it and fixed the low power power problem. That fan sucks 30 to 50 HP on some engines.
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I gotcha. Yea the boost pressure relief valve is a place to start.
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The HP and torque curves are so narrow with the AC and even worse with the AI engine. With a AC 427 engine traveling on flat ground at 65 mph your RPM’s should be 1600. Someone might have swapped out rear axles ( ratios) or transmission and gotten the torque and HP curves out of wack. This was a common issue on the AI engine in the dump trucks we saw. The AC engine was more forgiving
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Here is the bulletin https://static.nhtsa.gov/odi/tsbs/2020/MC-10180406-0001.pdf
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There is a service bulletin on this issue. I believe that some on the reman carrier housing had to be ground down in some areas so the bracket would fit flush up against the carrier housing. I’ll see if I can find it and attach it here .
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Like FJH mentioned, you need a boost pressure gauge. Just get a small liquid filled air pressure gauge better if it’s a 0-50 psi but a 0-100 psi will work, hook it to the intake manifold, there is a 1/8” pipe plug just for this . Using 1/4” air line run it in the cab and see what boost pressure your getting under a load, 33 psi is what I always shoot for on the ASET AC engines.
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