Mackpro

Speedometer older models.pdf

Part # is 243AX6F

It's push on fuel return line. The very early 98/99 ETECH engine has them coming off the back head. They later moved the fitting to the front head.

I remember replacing lots of the copper pump washers on the early Robert Bosch pumps. The new replacement washer was steel. I still have the socket for it. The later pumps had no washers at all

Pressure regulator part # is 21458307. Its located in front of head facing fan. Takes a 7/8" wrench to remove. Other possible causes, injector cups or fuel filter stand

We see alot of early ETECH air compressors fail due to clogged coolant port on rear of engine . If the head of the air compressor is rusty and looks like the paint is cooked off of it then the head gasket of the compressor could be blown causing coolant push.

air compressor coolant lines.pdf

coolant temp sensors ETECH.pdf

At the back of the water manifold on the LH side of engine. See if you have 2 temp sensors. One should face straight out the back towards the firewall and one out the side towards the frame/hood. If you do have two. The one out the back goes the the engine ECM and the one out the side goes to the guage. If your not getting fault codes and shutting down then the sending unit /wiring for the guage might be bad.

If your on 2 lane roads most of the time , I'd say it's about perfect. If your mostly on 70+ mph interstate, I would want some higher rear gears( lower number) to lower my rpm's for fuel mileage,

All this gun talk makes me think of my other hobby. I spend 8-12 hours a day working on trucks 5 days a week. The summer weekends are spent on the lake boating. The 3rd thing that takes up a lot of my time is being at the gun range. There is a nice small private gun club less than 10 minutes from my house. Most days I'm the only one out there. It's quite relaxing to lay some lead down , a little fireball action the other day!

The 2003 in 460 HP was a pain as well. The 427 and lower HP's were great. Also as you have figured out 2004 was not good in a CX and CH. In 2005 the CXN and CHN came out and got much better.

I thought it was high soot level but wanted to get to work where I could look it up and be for sure . Hope you got it figured out.

What year model? ETECH, CCRS and the two different ASET engines (AI and AC) all are difffernt in what needs to be changed or not changed in doing HP upgrades. Model of truck and last 6 of the VIN and I can tell you in the morning

I dont know about export but in the year model 1997 you could still get manual fuel pump E-7 engines as well as the VMAC1 and 2 electronic pump engines. In the year model 1998 you could also get the manual pump E-5 engine too. There are somehow, some export MP-8 engines running around here with no EGR, DPF or DEF

Turckster is right . Your EGR valve should only have 2 lines going to it. One from the back and one up from the bottom. If it has a extra line on the bottom ( steel braided drain tube) then I would change it, The ones with the drain tube gave us lots of issuses. EGR valve no drain tube.pdf

You got something going on for sure. Let me do some digging in the morning. Did you ever have any injector fault codes for this truck? If so , what were the FMI's?

You do a "cylinder balance test" in Tech Tool. Sometimes it shows a bad cylinder thats hard to find.

Yes , thats normal, the EGR Valve is not air tight , even when new. The air comes back around into the exhaust manifold. I wonder if the truck has an engine brake? The brake pistons could be backing out but you should have noticed it while adjusting the valves. Engine Brake piston.pdf

A cracked injector tip is way more common in the MP-7 than the MP-8. However a cracked tip usually shows as hard starting or no starting. Id pressurize the whole intake system and make sure the metal "U" pipe at the back of the EGR cooler is not leaking.

Is it a spark assisted ( has spark plugs in the bottom) DPF? I cant remember the year they got rid of the EMCON spark assisted DPF and went with the standard model like the CHU/CXU. If it is, the real question , can it do a rolling regen?

The ETECH/ASET Davco filters need to be a 7 micron rating and the MP engines a 25 micron rating. http://www.davco.com/filters.html

With the Davco fuel filter system on a Mack ETECH/ASET engine we use Mack filter part number 301-SD-19C. When the same system used on a MP engine we use a Fleetguard FS 19765. If you use the 301-SD-19C on a MP engine they will clog up fast. We know for sure cause we have done it several times! LOL

On the Macks CHU trucks with air ride. We had lots of chicken feed trucks that straight from the factory they sat level and straight. Then after adding PTO's and hyd tanks and all sorts of crap. They would lean down on the right front (bumper) and be high in the left rear (end of frame rail). Mack came out with a bulletin on the CXU and one for the CHU with different height replacement blocks to level the front ( right to left) . After getting the front straight the rear would also correct itself. Maybe its a weak steer axle spring? But if you got enough HP and cubic inches I guess you could tweak a frame. We never had that problem with the Mack! LOL lean.pdf