Mackpro

We still see alot of problems with the boost pressure relief valve, the screw on end cap on the newest style/part# seems to screw itself out and cause low boost. We screw in the end cap as far as we can and hammer/ping over the end to keep it from happening again.

Dont feel bad, I waited 3 weeks for some rod bearing for an MP-7 engine. Now have a 2011 GU with a bad dash display and Mack cant say when we will ever get one.

We have lots of CV dump trucks around here. With the AI engine the usual average MPG is 5.2 so your not off by much.

These were plain ETECH engines around 2000-2001. Trying to think if I have seen it on any ASET AC engines. Gearing and tire size is the only the thing I have seen help with power for the AC enines. Bigen (CHN AC ASET) said after we installed a coolant shutoff on his fuel heater for the summer his MPG and power went up?

I have seen improvements in power on certain CX style trucks that had the muffler underneath the cab/sleeper. That style muffler seemed very restrictive. A straiht pipe was put in place of the muffler. The truck wasn't to noisy but the dual exhaust was behind the 60" sleeper and had tall pipes. A friend has a 2004 CV dump truck with a AI-427 and had all custome exhaust from turbo to exhaust tips. He had squeezed 5" pipe starting at the turbo ( hard to do in a CV, you now have to remove the turbo pipe to get at the #5 and #6 EUP) all the way to a 6" TEE then 6" dual straight pipes in place of the mufflers. It did run better but you couldn't listen to the raido or cell phone while goin down the road. After about 6 months he replaced the straiht pipes with mufflers but left the larger turbo pipe and Tee and said it still ran better than stock.

What year and model? Mack made the 427 from around 91/92 till 2007. Startin with the E-7 VMAC-I , VMAC-II, ETECH, CCRS, ASET AI and AC. Now the closest thin is the MP-8 425. All had good points and bad with some worse.

I was looking at a brand new 2011 CXU and GU on our lot and neither one had the air clutch assist on them. Guess the boss man ordered them without. Smart move.

Change that filter ASAP as its does a better job at filtering than the 2 spin-on filters do. Its the best thing they put on a Mack engine.

Saw this on an old CH I was working on today.

It's a whole lot better to have oil running out of the engine ECM than antifreeze. The ASET's sometimes have the low coolant sensor leak antifreeze into the harness and it will make its way to the engine ECM and rot out the pins in the ECM. The MP engines usually have the oil level/temp sensor leak oil into the harness and usually not hurt anything but make a mess(sometimes cause weird codes to appear). So as long as it's just oil were are OK. Oil pressure or oil temp sensor is probably pushing the oil into the harness, we will get it figured out.

I'll make sure I have a switch and go ahead and try a new cap, just make sure it's a 16 pound cap. This cooler weather is causing lot of cold water leaks.

If you have a truck down with the bad cups, get the new style stainless steel cups and new style injectors. We have put several sets in. However today I had to pull a stainless cup out and replace it. The new cup didnt fail but the injector hold down bolt broke and the injector jumped around and damaged the cup.

We got the thermostat kit for $101. Yours is probably orignal and they were prone to leaking, as Rasler said these new style have a better o-ring for sealing.

You do have a Wabco compresssor and a Bendix AD9 air dryer on your truck. The Wabco compressors did have problems with their valves getting gummed up with carbon/sludge but this usually caused the compressor not to build up air or build up slowly. We had alot of Pilgiram Pride chicken trucks have this problem and had to replace the compressor head with a new updated head. Although I never remember it affecting the air dryer operation.

It does it have a MP engine? If so, it might be low fuel pressure due to blown injector cups. There is finally a fix for this as we have been putting in the new stainless steel cup's and new style injectors. Is the truck model a CV713 or a GU713?

Call Rochester Fuel they list performance CCRS injectors which are the same injector body as the AI injectors. I have talked to them before and they were very kowledgeable. http://www.rochesterfuel.com/products/etech-ccrs-stage-performance-injectorexchange-p-200.html

Thats what our DSM is also saying. The only problem I'm hearing is the DEF pump but Mack already has thoses in Reman.

We sold our 1st SCR truck today. It wasnt on the lot for a week. The guy took a test drive and the 505 HP made the sale easy. Started putting on the PTO and extra chrome this afternoon. Our sleeper truck CHU 505HP will be here any day, it was a custom order and is of course sold.

We have lots of 08+ MRU's running around here. Very few LEU though. I think I have a MRU to work on in the morning as we speak!

On some trucks (depending on software level in the engine ECM) the dealer can go in to the Engine parameters and uncheck the "air conditioning installed" . This way the Engine ECM ingnores the signal from the A/C high pressure switch and the fan should stay off if the problem lies with the A/C switch. However the 1999 CX I was working didnt have this feature but most newer trucks (2002 I think) do. The dealer should be able to use the laptop to check whats going on unless it is a bad Engine ECM. Does you dash have the fan override switch on it? If your truck has the APADS A/C system this could be the main problem. The APADS is a small square electrical box/ECM that is bolted near the radiator and has flashing lights to tell you the A/C is not working. The wiring on the APADS is so screwey that we always remove them and throw them away.

had a 1999 Etech in a CX today and the Horton air fan was coming on and off constantly. The water temp was only 180 degrees and the A/C was turned off. Hooked up the laptop and went to "switch status" and could see the A/C pressure coming on then off and the "Fan engage" was doing the same, this will happen even if the A/C is not turned on. Turns out it was a bad A/C high pressure switch. I also looked at the coolant temp and intake manifold temp on the laptop as if these get to high it will also engage the fan. Fuse 41 sends 12 volts to the fan solinoid the it returns back to the Engine ECM where the Engine ECM will ground the return wire. Basicly the Engine ECM makes or breaks the ground to control the fan clutch. It can be a pain to figure out without the laptop and Mack software.

Next time your in I'll turn it on where the fan will engage with the engine brake it helps. In the summer when going slow in very hot weather the A/C will kick on the fan clutch for 1 minute when the A/C head pressure reaches 300psi. I sometimes turn this down to 30 seconds if the truck is in dusty or farm field conditions so not to kick up as much debris. I cant remember what kind of fan clutch you have, I will look it up in the morning, I assume it a air operated Horton. If it has the Behr Electric Viscus fan there is no programing that can be done to it and you cant add a over ride switch on the dash. I got your cab shocks and air drier filter hid out so it will be here when you come by. The man up north working on the EGR bypass is waiting for me to send him some connectors but I have been covered up here at the shop for 2 weeks solid and I havent had a chance to talk to him.