Mackpro

Right above that EUP harness there is the air compressor coolant steel pipes. A short piece of hose connects the two pieces of pipe. The Mack part # is 160AX570P3. Its a silicone hose and holds up the the heat very well. Changed one yesterday and the workorder was still on my clipboard with the part #.

Piece of trash stuck in the oil pump by-pass valve?

If its a MP8 the oil pressure sensor and crankcase pressure are next to each other. The plug ends on the harness are the same, so the oil pressure harness can get plugged into the crankcase pressure sensor. Also make sure someone didnt bend over/kink the hose coming out of the crankcase filter. We see people bend this hose over while changing the fuel filters. It will set a crankcase pressure code code.

Oh the joys of Tech Tool 2. Every time they fix one issue with it they end up creating 2 new problems.

On a few truck trucks, even after replacing both nox sensors and doing 2 back to back regens and watching the NOX levels drop, the codes still show active. We have been able to then clear the codes and do 3 short test drives and codes never comee back. Mack had a SPN-5394 FMI-17 / SPN-4094 FMI-18 check sheet but its not on the Mack dealerportal anymore, they say they put the steps in Guided Diagnostics

90% of the time we find that the NOX sensors are the problem, They have new upgraded ones, we replaced a ton of them.

As Turckster said above, it could be the filter housing/hand primer pump, Tee valve on top of 7th injector (if equipped) , injector cups or something else. Years ago when I was doing somethimes 3 sets of cups a week, we got in the routine of not checking anything and just pulling the injectors out and replacing the cups. Back then about 98% of the time we were right. However those 2% made us look bad. One time I replaced the injectors and cups only to later find that the plastic elbow fitting on the fuel tank was cracked and sucking air, lucky warranty was paying for anything related to the cup/injectors no questions asked. air in fuel.pdf

If the code is MID-128 PSID-47 FMI-1, that a failed regen with temp to low ( the way im reading the book). I wonder if one of the DPF temp sensors is bad and telling the ECM that the temp inside the DPF is too low. Then the ECM is telling the 7th injector to open/flow more fuel to the point its melting the filter. I had a truck that kept showing low regen temps and the regen would stop due to low temp reading. We put a new 7th injector and cat in and it still show low temp during regen. we finally replaced the after cat temp sensor and this solved the problem. To much fuel or too much oxygen there.

As Turckster said above, I'd check the shims/depth. Here is a mack bulletin on the 3-4 code. 3-4 code.pdf

There were some bad "out of the box " 7th injectors out there, The dealer should have caught it as there was a notice about checking the date code/serial number on one befor you install it. A sticking EGR valve will cause the DPF to fill up to fast and well as the EGR Diff sensor being bad and telling the EGR to stay open to much. We are also seeing DPF diff sensors giving false reading and telling the ECM that the DPF is full.

There was a recall on some dashes, see if yours falls under this build date. Sadly the recall is expired. cluster 2.pdf

Is it a GU model ( I assume it is)? Here is the only Mack bulletin on the dash cluster but it wont help much. Id say either the cluster is bad or the data lines from the VECU to the cluster are bad. Check fuse to the dash cluster first. cluster.pdf

Injector cups strike again. Thats what I would shoot for.

They never totally free wheel. They always spin somewhat.

The top feed kit seems to work great but best i remember parts and install were around $2000. There were so many updates that were available to upgrade the Jakes that it was confusing on what was what. We usually started with the high voulme oil pump first and see if it helped. top feed.pdf

If your looking for new, there are none at the Mack warehouses in the USA. There are 11 dealers in the US showing one in stock however none are near you. I can give you some leads on the dealers that have them though

Unless it's missing all the time, For an injector code with an FMI-8 we just replace the harness end. Be careful as the harness will be brittle and the insulation will break off. I have put alot of these on over years. Mack says replace all ends but if the harness is brittle and coming apart when you touch it, I usually just replace the bad one. But its up to the customer if he wants to risk damaging the harness to replace all ends. My friends MP-8 has almost 800000 miles on it with orignal harness and I have replaced 2 ends on 2 different ocassions. His truck runs fine but his harness is about toasted. In his case he would rather be down a couple hours 2 times versus having a new engine harness installed taking at least a day or more( depending on who installs it). The injector harness and the rest of the engine harness is all one piece. injector harness.pdf

Mack is having lots of flasher problems on the newer trucks, I have seen melted fuse panels where the flasher plugs in to. Mack did come out with a heavy duty remote flasher to solve the issuses but they are high$$$

On most all Macks (except the 2010+) when both lights are on it's low coolant (or bad low coolant sensor)

How hot is it getting? Heres some info on the oil temp, this came out due to the complaints on the oil temp guages in the new style CX dash. sb210031 oil temp.pdf

We got the new tools last week but havent used them yet. We havent replaced any cups in a while, knock on wood!

Yes on the broke rings and your not yelling loud enough. Contact corprate offices. They should get you in touch with the dealers DSM ( district service manager), he can make things happen.

Make sure that behind the dash cluster, that the factory pugged in the correct wire according to what type of truck it is. We found lots there were incorrect and were burning up hood harness.

If you ever had to deal with Meritor warranty from a dealer standpoint, you would wish they never existed. The only time in my life where I made time to sit down and write a nasty letter to a corporation. That was about 8 years ago and I still hate them and things had not gotten much better. When my friends or close customers are specing a new truck I always make sure to steer them away from any Meritor items. May a thousand internet curses be upon them!

We get alot of new broke down MRU's towed to our shop. They are usually being delivered to the customer from the bed companies. I have seen a couple of MRU's with what looked like HD headlights. Never really paid enough attention to check them out. We also had a new GU rawhide show truck , on its way to a big show and it had some weird blue bulbs in it. However I have never seen a CHU with any aftermarket lighting.