Mackpro

It is made into the printed circuit board behind the speedo and tach. We just sold one this morning because the low air buzzer quit working, I thought they said it cost around 300$. If it were mine I'd try to solder one on.

We have seen this complaint many times and have also talked to the factory engineering several times. At one time they did have a download for this "rough idle" as they call it but I was thinking it was for 1999/2000 models and the 427 seems to have it worse than any of the other HP's. We have seen it where the whole truck shakes but as soon as you idle it up it goes away. We have never been able to get one to quit doing it. We did put a 100psi fuel valve on one and it helped but other than that no luck here.

This is true, dont reflash the eecu, Mack has a voluntary recall on alot of trucks in the 1999-2000, they offer you a free oil change if you come and let the dealer reflash/reprogram the eecu. More EPA bulls**t

I never really looked up the specs of the 460XT till now, but this morning I was checking out the 1999/2000 Mack tune up specs manual and the reugular 460 and the 460XT have the same HP "487" but the XT has 1760 ft. lb of torque and the regular 460 has just 1660 ft. lbs of torque. Make sure your turbo boost is between 27-35 psi under a load, with closer to 35 the better and fuel pressure going into the block around 100 psi, Mack has a 100 psi fuel valve, we put them in all the time. A good injector shop can add a little flow to your injectors, we use United Fuel and Turbo in Birmingham Alabama.Keep your air filter changed, watch your pryometer and make sure the hole in your hood is lined up with your air filter housing so your not sucking in hot engine bay air.

HP is at the flywheel on Macks. On the dyno Mack had the" 80/20" rule. You should get 80% at the wheels, lose 20% through the drive train. Last week we had a 2006 CV with a 460 and it only put out 322HP at the wheels which was very low, should have been around 365. Turned out to be weak injectors. We have a couple of 460XT's CL's around here and the guys love'em.

I agree, we had a simple dash and switches and now with the "volvo dash" everthing is super complicated, even the new wiring diagrams are hard to read. The VCADS program is a pain to use, before VCADS we could run out to a truck and check mafunction codes with the pro-link or laptop in a couple minutes. Now with VCADS we have to bring the truck in to the shop because the battery in the laptop will run down before we get the codes read. I like the engine and frames and most everything about the new trucks but wiring and electronics are volvo and are to complicated for what it needs to be. If volvo came to rewire your house it would take 2 extra tons of copper wire to do it their way, they cant make a simple light circuit without running it through 2 relays, a computer module and then working it of a ground.

In 2004 the ASET engine came out for EPA reasons and after that first year Mack found out that there wasnt enough room for the bigger radiator and aftercooler needed for the ASET's water cooled EGR system, all that extra heat put a strain on the fan belts on the 2004's( ask anyone who had one) under hood temps were so hot they would melt the windshield bottle on the fire wall. Going to the "N" frame standardized the frame parts for the MACK/volvo assembly line. 2004 CX is 34" wide at the front and CXN are 42 and a half if my measurements are correct.

I was doing a recall on an MP8 the other day and had the rocker arm shaft off [ about 150 pounds] and its built like a tank. I was dreading working on it, but now its not that bad at all. Its just that its so different than the E-6,E-7, ETECH and ASET which really have changed very little in the past 30 years. Its like working on lawn mowers all your life then one day you start working on corvetts, kinds scary at first.

Our biggest DPF problem here lately had been drivers hitting the "delay regen " toggle switch and forgetting to hit the regen button later, and they just keep driving till the DPF gets plugged and derates the motor till we have to go get it with a wrecker. I working on one as I type here. The salesmen sell these trucks and dont tell the owners or drivers about the DPF switch and how to use it and it makes it look bad on Mack when they get towed in all the time. The instructions i get from Mack are vauge in how the DPF switch works, I wish they would make it eaiser to understand for thr drivers.

After doing several small recalls on 3 CXU's during the last week , I decided to run one down the road for a test drive. The truck has a M-P 8 415C , 3.73 gears, 10 sp fuller and 22.5 fullsize tires. I could not believe the power, it pulled to 2200rpm in every gear and pulled hard. On a very short on-ramp on to the interstate I hit 70mph from a dead stop from the stop light to the interstate. I have drove the MP-8 485 hp before and this 415 hp was almost equal in power. Of course this is with no trailer or load. It reminded me of the V-8 when driving, it felt like kicking down in passing gear on a car. I know alot of people on here dont like Volvo and us using the volvo motor in the Macks but we finally got a motor with a 100 cid more than we ever had since the V-8 days. The MP8's are holding up great, the only problems are with the damn DPF filters that we have to run on them, (thanks EPA) We have yet to have a low power complaint on any M series engine(except for DPF derates) and we have quite a few running around here. Any one else out there drove any M series engines?

I will agree, as we have had no crossmember failures or any other frame problems with the "N" frame like we did with the regular CX/CH. I replaced alot of crossmembers behind the cab and under the 5th wheel on the CX/CH when they were used to pull tankers and when used offroad/farm use.

In 2005 you could get the "N" stlye frames, we called them "volvo frames" they are wider at the front and allowes for a better radiator/aftercooler setup plus they are alot easyer to work on versus the 2004 cx/ch with the ASET AC engine. The "P" style means it has the deeper cab behind the driver seat, new style "volvo" dash and MP-7 engine only. The "U" style means same as "P" but MP-7 or MP-8 engine but has DPF exhaust filter. And after working on 3 different MP-8 engines (DPF issues) in the last 4 days I say stick with 2003 or older CX/ CH's and 2006 or older CV/CT's if you do your own services/manintence.

My scanner isnt workin so i took a couple of pics of the fuse panel diagram, hope it helps, this is for a 1988-1992 ch mechanical fuel pump truck. If you can read some of it let me know.

I found the truck using our Mack warranty system, its a R688st, put inservice on 8/6/87, must have been a fleet truck as there was 20 made exactly the same one serial number apart, it has a E-6 300hp 4-valve head engine, trans is a fuller XF12609AX. it has rockwell rearends with 4.44 gears. The vin# is 1M2N188Y6HA018998. Hope this helps.

Every time I go to Mack school (Joliet or Atlanta) I always stare at this one "Mack"poster they have on the wall, Its a V-8 with 4 turbos, they say it was as a tank engine but was never used in production.I think it was rated at a 1000 HP.

Forgot to ask, what was the fuel pressure going down the road? should be 80 to 100. I have had trucks that had good pressure at idle but low going down the road. We just overhauled a 2000 460 etech last week and the "new" mack reman heads were bad, with low compression. We have also seen remack heads come with the intake valves installed in the exhaust valve locations.

Last year I swapped an engine in a 2006 CV (AI400). and after the swap the truck had very low power, I worked 3 days on trying to get the power back up. Problem was i had left a ground wire off the grounding bolt on the block below the starter, it was like daylight and dark it the power. Check the ground wires at the starter and ground breaker on the fire wall. worked for me, good luck.

You cant wear that motor out, its bulletproof. We only keep 2 parts instock for Midliners, the clutch master cylinder and slave cylinder and thats it. Parts are hard to look up and every time we order something it comes in wrong. The interior cab parts are kind cheap and flimsy but over all I would buy it if the price was right. They seem to last forever.

Back in the late 80's while at the Mack school they told us to use " edible beef tallo" (exact words) to lube the rubber bushings. When I asked the instructor what this was he said cow fat. While writing this reply I looked in my old Mack service manual for a MB685 printed in 1973 says to " coat rubber insulators with liquidsoap. do not use grease or oil."

Many years ago when I first started working at a mack dealer I had to pull a injector on a ole 2valve head E-6, I tried the pry bars and no good, then squirted PB Blaster (very good stuff if you havent tried it) down the side of the injector and tried the pry bars again and still no luck. I found an old injector line and cut the nut off of it and welded a hardened large washer to it, then screwed it on the injector and attached a chain to the washer and hooked it to our overhead lift and pulled up with the lift and used a air hammer to finally break it loose and out it came. I have seen guys do this and have the front tires off the ground but that was to dangerous for me. Trust me they can very hard to get out.

We have streched out a CX and a CXH and have had rv bodies (38foot) added to the back of the cab, They were really nice, only problem is turning radius compared to regular rv's. The first one we had built was at Showhaulers and the one we are having built now is at S&S. Our boss has race cars and uses these to pull the trailers. The CX had a eaton auto shift and the CXN had a eaton super10 but we changed it to a auto shift also.

Cool site. When I first came to work a Mack dealer back in 87 we had 2 old striped (mint condition)Brockway cabs out back in the bone yard. They looked like F-models but said brockway, one was lime green, the motors were missing, an old timer that was working here at the time said that one had a Scanny? motor in it. I'll never forget that lime green cab, sadly the cabs went to the crusher.

I was impressed by how small the I-shift trans was. The one I saw looked like it had a aluminum case and was not much bigger than a 5 speed mack 200 series trans. I dont know what model of I-shift it was though.

If its a 4-5 code, most of the time its the wastegate on the turbo, we replace alot of them, seems the diaphram blows. We have also seen them not adjusted right and then getting to much boost, it is very important to adjust them by the book, its a pain in the ass to do it that way but its the only way to do it right. When the dealer reads the codes he can go to the fault reporter and it will tell him the exact time and date the last 5 code were active, so try to remember time and date of fault and have them look it up. Alot of the time there are so many codes on a truck we dont know where to start so we clear all codes , let them drive it a week then come back and see what codes have reappeared. If the codes havent been cleared in a long time you could be chaseing problems that are no longer there.

Volvo is now importing their I-shift trannys, it's an auto trans kinda like the newer eaton autoshifts, we saw one in school last year but it was 48volt made for the middle-east market. I did hear that it would be offered in macks in 08 or 09.