Mackpro

If the the truck came with a oil temperature guage, the sensor for it would be right by the oil pressure sensor as well . The oil pressure sensor will always have 3 wires and the oil temperature sensor will have 2 wires. It’s common to find these sensors broken after a starter change it seems .

RB and RD’s with Etech engines came the the VECU ( vehicle control unit) mounted with the connectors facing up right under where the RH windshield would leak and drip right into the VECU. This caused lots of issues including throttle pedal issues. Pull the kick panel down in front of the passenger seat and see if the VECU is facing up , if so unplug the 3 connectors and check for water damage and corrosion,

I believe those two connections are the same towards back of head . Got them plugged into the wrong sensorharness . swap them and see what happens

I found 3 bulletins on the LR HVAC system. There is a little known process of calibrating the actuators for air flow , I’ll get them sent out in the morning

They were both for non-engine brake or powerleash brake engines with ceramic lifters. Both can’t be used with Jacob’s engine brakes . The 5247 is the later camshaft for use with Step 4 engine software

Power divider or axle inter lock engaged . Is the PTO light on the dash on or engaged . Both of these can limit road speed . Also if rear suspension is air , if air bags are down it can limit road speed as well

https://static.nhtsa.gov/odi/tsbs/2015/SB-10082931-0699.pdf

The 85133799 is for the newer MP engines starting in 2008 with DPF and actually will work in engines all the way up to the common rail engines.

The EGR valve for the 04 Emission MP7 only fits that particular engine and they only made it for one year so it’s a oddball part . The part number you listed is a good part number for the kit that includes the valve , gaskets and clamps. The part number for the EGR valve by itself is 20784883. And of course no stock anywhere at the Mack part distribution centers or dealers .

The air compressor gets its fresh air from a hose coming from the back of the intake manifold. If the hoses or piping are leaking you will have low turbo boost ,

Only the pre-CCRS /ASET engines used the off set can key . Not sure if it causes low power but I know in a 2000 RD bumped from 400 to 460 will over heat in the summer . I know cause I did it . Lol. Winter And spring we’re ok but the summer heat was to much , putting in the off set key way fixed the overheating.

I don’t know exactly when the ceramic roller abs spring loaded push tubes were phased into actual production but they can be found in any ETECH engines out there as they can be used any ETECH out there, the ceramic rollers are quieter and if properly maintained they last longer than steel. But a spring loaded push tube must be used on the exhaust rollers as the .024” valve lash is to much slack and turns a solid push tube into a jack hammer and shatters the ceramic roller over time. The .016 lash on the intake seems to cause no trouble. That’s why valve adjustment and updating the rocker arm hold down bolts are important. You can sill get the ceramic or steel rollers

Neither . The ASET AC and AI Engines did not start till sometime in mid to late 2003 for the 2004 model year. A 2001 is also a confusing year. As that year you could have a regular Etech engine or a CCRS engine. And some parts between those two engines such as EUP’s, turbo , injectors camshaft won’t enter change with each other

There are 2 different cartridge style water pumps for the ASET engines , one for the AC engine and one for the AI engine. One has a 5.27 inch pulley and other has a 5.88 inch pulley, the wrong one can be easily installed and cause cooling issues.

The air line goes to a small solinoid mounted on a bracket on the far LH side of the fire wall under the hood. These solinoids are very prone to failure. So much so that we quit ordering trucks with air fan clutchs.

The install tool does it all . There is another tool that can be used to check alignment from the bottom but it’s not a true install tool

You have to pull the head, you drive them into the top of the block with a special tool . I would pull both heads and check all H rings for height and alignment with the tool . https://www.freedomracing.com/j-41683-a-h-ring-installation-tool-alt-st-271.html?___store=default&gclid=Cj0KCQjwyN-DBhCDARIsAFOELTkQYu8bovPFGcCPy2y3lwijWKKRUkv5vQDubzklDPSd8BvcFQuMN3kaAh8wEALw_wcB

I wondered about making the “Y” from metal gas pipe fittings , that way you could use 3 pieces of straight hose . A “Tee” and a smaller elbow and a reducer bushing and 3 pipe nipples and your done

On our CHU’s and CXU’s , we have be having to replace the short harness from the front chassis harness up the the coolant level sensor. . Either the harness ends went bad or wires pulled apart inside the insulation.

There are a couple of bulletins on this code. If a pre common rail MP8 engine , clear code and keep on trucking . If common rail engine then pressure test intake system , pay attention to charge air cooler/CAC for leaks .

https://static.nhtsa.gov/odi/tsbs/2014/SB-10082801-0699.pdf These are the 2 bulletins we always followed and fixed the issues 99% of the time .

https://static.nhtsa.gov/odi/tsbs/2016/SB-10083430-6903.pdf

Grade Gripper is sticking and keeping brakes engaged/ slow to release. Mack has released a couple of service bulletins on this . It was a common problem. Fix was a new solinoid valve and quick release valve

Factory/dealership HP upgrades for MP8 should be fairly cheap. If you have a Mack transmission and truck is out of warranty. The dealer cost to go to 505 is usually around $200 , the dealership will usually mark that up 30% or $100 and charge 1 hour labor to install it . If the truck is still under warranty the the cost of the download is the difference between the cost of the factory engine versus cost of a 505 HP engine at time of purchase. Usually $1200-1400 plus markup and labor to install . On some year models there is the 505 Plus download that has an extra 100 ft pounds of torque that you can get . You can’t get the 505 if you have a Fuller trans with a low torque rating or if you have a Allison transmission in a GU . They do have a 505 E download that’s for trucks with smaller Fuller trans where you get the 505HP but not the bigger torque. If a dealer is gonna charge $4-5000 for a factory upgrade, you need to find a new dealership.

The engine brake plungers are known to unscrew themselves and cause issues as well . Mack sent out a bulletin and tools to dealers to tighten the plungers . Every time we had the rocker arm shaft of a MP engine we would check the plungers and see if they were backing out https://static.nhtsa.gov/odi/tsbs/2017/SB-10090649-6903.pdf