Mackpro

The early CH/CX style trucks had the metal air filter housings. They alignment tabs on them to make sure the housing pointed correctly towards the hole in the hood. This alignment tab was easily bent caused the mis-alignment issue and low power complaints. Later the plastic air filter housing came out and eliminated this issue. The air filter for the plastic housing is smaller and seems to clog faster than the larger filter for the metal air filter housing. Back in 2014 you could still order the larger metal air filter housing on GU’s . The referred to these as a long life filter. We worked on some new very large off road only GU813’s that had the larger metal housings.

That’s good

The cable was available but as far as all the other cab parts for this set up its hard to say what’s available

The original part numbers for those 2 throttle cables were 27RC353P85 and 27RC340P85, the number after the P is the length in inches. They make different lengths just different P numbers. These 2 cables were replaced by the 25162402 as I said above.

Yes , manual pump with cable throttle

The original part numbers both show 85” long cables . I know they made all different lengths of throttle cables

I gotcha

Ch613- 002177 E6 with what I believe has an American Bosch pump on it . Ch613-003377 E7 with a Robert Bosch pump . Originally they used different throttle cable part numbers . Now it goes to the same one 25162402 and plenty of stock out there.

You have a E6 or E7 engine?

We finally cut up one of the expansion tanks that the low coolant sensor pushes into . The sensor pushes up into a pocket with coolant around it but the pocket is sealed and no coolant actually touches the sensor. There is a floating plastic ring with a metal washer inside it that floats up and down over the pocket that holds the sensor. To test we pulled the sensor out of the expansion tank but still plugged in to the harness. With key on , the low coolant alarm went off. We slid a metal washer over the top of the sensor and the low coolant alarm went off as long as the washer was near the top of the sensor. Slide the washer to the bottom and the alarm cones on.

Front drive axle hubs 11QJ4222 (25131406) and the rear drive axle hubs are 11QJ4222P2 (25131407). Old and updated parts numbers shown . Only difference is one has the tone wheel for the ABS sensor to read. No stock at any of the Mack parts warehouses .

With out a VIN it’s impossible to guess. To many axle combination possibilities. A local guy here ordered 7 CTP’s with the spoked Dayton style hubs front and rear to match his older trucks.

The bell housing is pretty much sealed from engine oil so it point to the rear main seal. They update the rear main seal a few years back . The new one goes in what looks like backwards best I remember. We put a couple in and they leaked worse. We found out that we put them in backwards. Check your transmission fluid If you have a Mack manual transmission, the oil pump for the trans cooling is inside the transmission bell housing . We have replaced the piping and hoses and o-rings inside the bell housing multiple times on our manual trans trucks due to leaking into the clutch area. There was updated parts fir this as well. In one extreme case I saw a bull gear go down and eat through the rear engine timing cover/bell housing.

The older ones had the part numbers right on them . 17QF***P*** would usually be the number. The numbers after the P were the important ones. This was the variation or length number.

The good thing about VMAC 3 ECM Programing ( ETECH, CCRS and ASET) is there are ways around asking corporate for permission for HP upgrades. With dealer access you can program as many ETECH engine ECM’s as you want with the XT file. Now finding a dealership that knows how to do it and that will do it is the problem.

Most all ETECH’s will only turn 1950 in the last/top gear. However 2100 or 2150 ( I can’t remember) in all the lower gears is normal. I think the ASET AI with AMI engine data files ( AMI 370 for example) would go higher in the last gear. There might have been a few other specialty data files that would go higher as well.

There is a dimmer switch for the dash lights. I have replaced a few that were bad. Not sure if there is a fuse just for the dimmer it’s self .

As Vmac3 mentioned, there are very specific sealing procedures when putting a head back on a MP engine. On the upper rear timing gear cover. The early ones were aluminum and were good. Just change the rubber gasket and all is good. The newer covers are plastic and junk. I replaced the whole cover every time because they warp and leak. Also using the hood down tool that pushes the cover down while you tight the screws is a must

it’s worth a shot.

This is really a hard one as all the start relays go back to the trans ECM that is no longer there . Somewhere there is a Relay #20 ( Mack doesn’t say where) start enable relay. It doesn’t show up on any of my fuse box diagrams. There is also a relay usually mounted on the outside firewall labeled MEIIR, I was hoping jumping this relay would work but it won’t as it goes back Trans ECM. The trans ecm powers up 2 relays sorta in line , the hidden relay 20 and the regular start relay #36 that in the fuse box by the clutch pedal. The main goal is to get 12 volts on wire CB28A at the VECU connector B pin 28. You also have to put 12volts on the CB28B wire at relay 20 which will feed back and engage the regular start relay 36 . Be very careful with relay 36 it can be turned and inserted 90 and it will never start .

I’ll see in the wiring diagrams for a 2012 Auto shift if it’s a simple jumper harness added in like the older CXN and CHN’s

The engine ecm controls the ground for that small solinoid on the starter. The engine ecm looks for the start signal from the VECU, which is looking for a neutral signal from the now missing trans ecu . The VECU can be reflashed from the dealership to a manual trans. Years ago Mack would not this on the 2008 and up trucks but a couple years ago they said they would. Removing the Auto shifts and Ultra Shifts in the older grey engine trucks was easy to by pass all the wiring . Not so sure on these MP equipped trucks

There was a software update for the EGR cooler efficiency code some years back . You can remove the hose and elbow on the front of the cooler and blow it out with blow gun . Wear a mask because black soot will fly everywhere. Then replace the EGR temp sensor and clear code . I’ve had decent luck doing that when replacing the EGr Cooler wasn’t option due to parts availability

Mack really does not recommend this but you can have the axle bent to get the camber right . A local heavy duty alignment shop here does it.

As in exhaust flow abs pressure through cooler ?