Mackpro

I have a couple of blown up one's laying around, I look for any model/series markings on them. Mack/Volvo doesn't tell us any specs on anything anymore other than part #'s. We used to have engineers we could call for info, those days are gone. We have been replacing several MP8 turbos as part of a recall. We have to reuse the old actuator though. We had one of the new recall turbo's blow oil out the back/exhaust and ruin the DPF filters. Total bill was $8,000+ , thank God for warranty.

Yep , thats them. We had a small Cummins engine in the other day and it had the same turbo on it as the MP's. Of course our MP turbo's from Mack in a Cummins box! The first MP-7 (non-DPF) turbo's had a problem with the impeller nut spinning off but that has now been fixed. The turbo center section is water and oil cooled and the VGT/actuator is also water cooler. The MP7 turbo to exhaust manifold gasket had a normal looking turbo gasket but the MP8 turbo gasket had a very small hole/ block off plate in it (?????). Never seen a MP10.

From 1100-1500 rpm 30psi, 1700 rpm 35psi and 2100 rpm 40psi. This is measured with a special oil pressure test kit and at hot oil temp. Book doesnt show where the guage hooks to, Just says to follow the instructions in the kit. We have found if the Engine brake works good for the first 10 or so miles and then quits when the oil temp gets up. We first put in the new high voulume oil pump and if that dont work we install the external oil supply line kit. Of course make sure it has the new style oil check valves on top of the rocker arm brackets and that the solinoids are not pouring oil out the bottom with the engine running and valve covers off.

The electric window switch is in my hand, I'll lock in in my tool box so I know it wont get sold!

I'll get a switch if we aint got one already. I wouldn't change the screen but once ayear due to the possiblity of damageing the "Y" hose below the screen. Your cooling system/block/piping looked great and wasn't rusty/crusty like some I have seen. Our local Best One Tire does all our tire balanceing. We have a local small guy who balances with the tires on the truck, so the hubs and brake drums also get balanced and he solves alot of our vibration problems. Bad thing is there's a 2 week to a month wait to get to him.

We have a really big nice wall chart that shows all the different ring gear/pinion and bullgear combos but cant really post it here as it is huge. On the 92/93 series there are a 51,52,54 and 55 tooth bull gear (big gear in the bottom) and the various ring gear/ pinion combos that go from 3.65 to 9.59 (according to Mack Carrier Service Chart booklet 13-501). I think they did discontinued some ratios years ago but I cant remember. We usually try to just change the ring gear/ pinion (leaving the bull gear alone)to go up or down. Alot of the time just changing the ring gear/pinion is a big jump up or down so to go just 1 step up or down you have to change all the gears. I guess making the big jump up or down then changing your tire size you could get by with it. My little booklet has 66 pages of gear charts covering all 92/93 series to much to post.

I dont blame ya for saving your brakes!

While I was adjusting your valves the other day, I did take out your engine brake solinoids and replace the o-rings and all looked good. How's the fridge working? Havent heard from ya?

Mack does have a book that explaines most 07 emmissions codes (manual # 8-218)however it dosent explain how to repair. And also some codes are not in the book.

Rhasler was right on with that service bulletin as we have changed many of the cab exp valves that somehow affect the sleeper A/C. We should have the new exp valve in stock but I will make sure. Wish I could have snagged that fridge before you as it would fit perfect in the cabin of my boat!

Look at the housing and see what name brand it is and any #'s. It's probably a Sheppard M100 or a TRW/Ross TAS65. Let me know, some have adjustments and some dont.

I would go with a aftermarket boost pressure guage (the boost and manifold pressure guage means the same thing, some people call it one or the other). If your truck has one it will be in the upper left hand corner of your dash. To install a factory boost guage the dealer has to reflash the ECM to read the new sensor and transmit it to the new guage. The aftermarket guage just hooks a piece of 1/4" or 1/8" plastic air line to the intake manifold and goes straight to the guage in the dash. http://www.pdqperformance.com/product-p/114524.htm

Best I remember this was an unoffical fix that problem and no service bulletin existed. I remember talking to our DSM (distric service manager) and told us to how to install the resistor. The 680 ohm was installed inline on one of the two wires at the intake manifold temp sensor. I will try to find out more.

Thanks for the info, I'll see if our parts guys can keep a kit or two.

The engine is a ASET AI. The 370HP was not made for to many years due to the EPA finding out how dirty it was. The 370 was dropped but they kept the 300, 350, 400, 427 and 460HP till they went to the MP series engine. Alot of state road dept dump truck had this engine. Best I remember the performance was equal to the 427 HP on paper (torque output). Most everyone around here didnt complaine about low power. Main thing to watch on these engines is the belt tensioners/belts, air filters plugged easy in dusty conditions, if it has a Powerleash engine brake have the valves adjusted and make sure they replace the rocker arm hold down bolts with the new upgraded ones. The Horton fan hubs also have bearings that go out and most Horton fan drives have the built in fan clutch that seems to go out/slip early. Always use Mack filters and dont forget to change the spinner oil filter. While at the Dealer get them to reflash and reprogram both ECM's up to the "Step 12B" with throttle calibration (makes them run better) The torque curve of the AI engines can sometimes be small so if the pulls good dont go changing tire size. I'm not much on pryometers/EGT guages but I think a boost pressure/manifold pressure guage is a must.

Hooked up that fridge you were wanting to make sure it worked and it did make ice!

The bottom exhaust manifold bolt holes in the heads are drilled all the way into the push tube opening. Oil runs down the push tube to the lifter, the oil stays there and can come out past the lower exhaust manifold stud. We remove the bottom studs and put silicone/RVT on the threads (threads of the stud only)on the stud and reinstall. It's a common problem . All ETECH style engines are like this.

Just replaced a FIC module on a truck just like yours. This one quit running and never would start back. The FIC would not supply 12v to the injection pump. We have several test ECM's here to use so it kinda makes it easier to locate the problem. Glad you have about got it figured out!

I know we put alot of fuel supply pumps on. You can remove yours and see if the gear is slipping on the shaft. Also check your oil level for being over full. Sometimes these bad supply pump can leak fuel into oil. Does yours have spin on fuel filters or the Davco filter in the clear housing? If so it has its own check valve.

If I was at work I could get you the Service bulletin #'s but I wont be back till Tuesday. Also has the engine ever had the injectors replaced? Some over fueling injectors could be the cause although probably not. Too much fuel or not enough air (boost) usually causes high exhaust temp. If you have any type of fuel heater make sure it is shutoff. Make sure the hole on the inside of the hood is lined up with the air cleaner housing hole and the rubber boot is sealing off the hot air off the engine.