Looking at a mack

[Speedy55]

I’m going to look at a Mack dump truck tomorrow. It’s a 2004 with a 427 engine, double frame and a 15 foot bed. It has an 8LL trans. Anything in particular I should check or watch out for? 

[JoeH]

Engine codes. Make sure the lightning bolt comes on with the key and goes out promptly.  There's a write up on here to turn that motor into a really good engine, it's currently set up with exhaust restriction to force it to return some of its exhaust.  

Watch for double frame rust jacking, cracks in the frame, etc. Replacing frame rails is 25-30k. Unless you can do it yourself, then you'll be looking closer to 15k for the rails.

[Mack Technician]

Your buying into the last generation of Mack engines. Good engine if properly adjusted and slightly modified. 6 years of post-factory R & D to eliminate a lot of the base engine issues and cam problems, so a well developed engine. The emissions system is 100% internal, so no plugged EGR coolers and stuck EGR valves to constantly nurse back to health.  A good truck to be the "end of life user" of since the engine is still somewhat simple.

When friends ask me to go check on one I take an oil draw pump and coolant SCA strips. I draw an oil sample with a drop tube and check the Coolant Nitrites. If either test fails, no buy. Check for white foam around the engine breather (coolant leaking internal). Check for cracks in the frame X-members. Check for signs of oil leakage/paste (cracks) from under the rear spring seats (if its not a camelback). Bring wrenches to check for milk oil in trans and rears. Make sure rear diffs have breathers in them and not busted off water funnels. Check for 11 and 7 o'clock leakage where the diff body bolts into the axle banjo(if mack diff).  There's a lot of topics on this website if you search CV713.

Best case scenario....owned by fleet or previously some lease program. Worse case scenario...owned by farm operation or salvage yard. Sorry to farmers.   

 

Click on....

 

Edited June 14, 2019 by Mack Technician

[Mack Technician]

On 6/14/2019 at 5:11 AM, JoeH said:

Engine codes. Make sure the lightning bolt comes on with the key and goes out promptly.  There's a write up on here to turn that motor into a really good engine, it's currently set up with exhaust restriction to force it to return some of its exhaust.  

Watch for double frame rust jacking, cracks in the frame, etc. Replacing frame rails is 25-30k. Unless you can do it yourself, then you'll be looking closer to 15k for the rails.

It's debatable if you should waste your typing on a new user with no content. 4 out of 5 never open their account again after an initial question as is the case with our man Speedy.....

Edited June 19, 2019 by Mack Technician