Mackpro

We had alot of rear brake problems on some of the last CXN's and CHN's. Something in the rear relay valve/ABS modulator valves was going bad. At the time you could buy all 3 valves assembled together and made for a easy install. All 3 were bolted together on the crossmember in front of the front drive axle like the pic shows.

Better have 4.42 or 4.64 rears and the engine needs to be a AMI370 , AI427 or AI460 before I would even look at it. . Performance even at 460 HP is OK but not great I guess. As far as MPG . 5.3 average is the best I have ever seen but 4.3 to 4.9 is what I see most. Most of my friends are slowly upgrading to GU MP-8's in the last couple of years and are very happy. Amazing what a 100 extra cubic inches does.

As far a regen, a clogged 7th injector or bad AHI module could be the problem. And we have see turbos cause it as well. scan0446.pdf

Behr Fan kits.pdf

Your truck came with the Borg Warner HDMS fan clutch. They are junk and we have changed many of them , sometimes 2 or 3 times on the same truck. Mack no longers sells them. They now have a change over kit to the smaller/better Behr fan drive. You can install the kit yourself but a dealer has to download the new program for the new fan type of it wont work. Also pull water pump and check for slipping impeller.

Finally found it, your daytime running light relay is probably missing or bad(DRL)

What's the last 6 of the vin and model number, that code is not coming up on my list.

Sounds like you replaced everything. We had some FMI 7 injector codes due to engine brake pungers sticking. I'm still looking

Heres what we see on most all FMI 5 injector faults injector Harness end connectors.pdf

You know that the actual fault code was SID number and FMI number?

Ignition solinoid in dash on the VMAC 1 and 2 in the fuse box. And no they don't last long if you use the truck daily. Most of the older trucks around here farm trucks that are only used seasonally so the solinoids last a lot longer. We have tried different ones but the Mack ones last the longest.

I might have a better diagram, if I can find it. But heres the complete diagram 07 GU CHU CXU wiring digram.pdf

The round "green" pressure sensor in the high side line is for the AC/fan clutch. Unplug and fan should speed up. However if the AC system has the "flashing box' APADS system installed under the hood, then its a wild goose chase.

If enabled in the ECM programing. If you have no speedo signal it goes into limp mode. The wires go to the ECM and then out of ECM to the speedo head. Wires numbers ontop of the trans should be 11-F-16 and 11-G-16

A large chicken producer with a fleet here, tried the twin Y. While not actually going off road, their feed haul trucks do get in some uneven conditions and some of their other locations had issuses with the trailing blades twisting and cracking. Also I have seen pictures of the trailing blades ( Y-arms) bent and twisted in panic stops. We did a campaign on replacing all the Y-arms with much heavier ones. However , with the much heavier arms, your weight savings wasnt much over the standard proven air ride systems. The customers next two batches of truck orders had the standard air ride. I just test drove a 2015 CXU with the twin-Y after a engine repair. The customer has never complained but to me it feels squirrelly in the rear end. You change lanes and it feels like the rear axles are coming around to pass you. I inspected and everything seems tight. scan0437.pdf

http://www.rhsheppard.com/customer-service/service-bulletins/

http://www.rhsheppard.com/customer-service/service-and-instructional-videos/

I have the 2005 Maintenance and Lubrication Operator's Manual on a PDF file but its too large to put here . Message me and Ill try to send it by email. The Operators manual and engine manuals are still available through the dealers and are actually cheap unless your dealer jacks the price way up. You should be able to get all 3 manuals ( maintence/lube, operators and engine ) for under $100.

I didn't say he was legal! Lol . No , not coal. I'll try and pull his trip records next time he's in the shop and post it here. It always seemed to me that you were hurting the engine when running that low of RPM down the highway, but these MP8 engines seem to love it.

My buddies 2016 CHU 505 Plus with a T310 trans and Meritor 3.21 rears , disc brakes all around and super single tires does a very good job even grossing 99,000 pounds when I rode with him a week or 2 ago. And gets regular 7MPG. Stay away from the twin Y ride, I've seen lots off handling issuses and pics of mangled brackets during hard emergency braking. 2017 common rail sweet spot RPM.pdf

If you plan on keeping it yes. How many miles are on the engine? What's your oil usage? But I would first find out the reason for over heating. Pull the screen out out the "Y" pipe and pull the water pump off and check the water pump housing for putting . Have radiator cleaned and check fan clutch operation. Is it a air fan or electric viscous?

Really they're just a getting a different cab. Same Cummins Westport engine, Eaton trans and Meritor/Eaton axles as used in the Macks.

Heres something to think about when choosing your rear gear ratio. This is then sweet spot RPM's for the 2017 common rail engines. And yes , skip the the MP-7, resale sucks. Get the MP-8 with the 445 HP. As Jim said above, the extended warranty is cheaper below 460 HP. If your going with Eaton trans, get the higher torque model because if later you decide to bump it to 505, Mack wont turn on the download if you have the smaller Eaton trans. We are selling lots the the disc brakes but you cant get the Mack axles with them. The Meritors are lighter any way and unless its a logging truck (CXU/CHU) we rarely put Mack rears on CXU's or CHU's. 2017 common rail sweet spot RPM.pdf

I'm glad you found it !!