Has anyone had trouble with the belts blowing off the front of the motor on newer Macks. The company I worked for had a lot of trouble with this. This is the last thing you need with a concrete pump! 

We haven't had too much trouble with belts blowing, since we replace them regularly and check them all at every service. However, we have had a tremendous amount of trouble with the new clutch fan design they started using about 3 years ago. All the new ones have this design, and Mack has yet to modify the design, despite the numerous fan clutches they have had to replace under warranty for our company. Somebody should look in to redesigning those things.

Tell them about pulling a stuck conventional Mack. That was too funny.

Pump Monkey,

I believe that there is an alternate assembly available... but you have to ask for it.

There is in fact an alternative fan assembly available upon request from the Mack dealer who most likely sold the truck to the pump manufacturer. We just replaced a few on our own and customers pumps.  They are still loud, but do not engage as often. MUCH better than original.

So Bob 30 clutch fans go on warrenty and Mack does not suggest that. Fans yes there is an upgrade, not clutch's.

Correct me if I am wrong, clutch's.

Sort of pizzez you off doesn't it!

I found out about it by accident. (figures)

FINALLY, when the fix was in the first truck I asked the company's shop supervisor what the deal was; his answer was a classic.

"The old clutch was either in or out. The effect was like coasting down a hill at 100mph and enganging the clutch by slipping your foot off of the pedal."

I thought that about said it all.

The new (secret) clutch engages more slowly (or so I am told; and that is why the belt problem goes away too.

Leaving the air conditioner on while you are pumping is another reason for the short belt life. The AC clutch snaps onn and off as well.

I am not a diesel mechanic and this information has come from what I consider informed sources.

$145,000.00 and they have secrets, fair? oh I keep forgetting, the fair is in August!!! ;~)

i find if you dont max out the rpms you have a much lower chance on tossing a belt

not all mack dealers know about this im from massachusetts i found mine at wisconson mack

Its called a two speed fan. The fan is always running at speed one instead of being off. This allows longer breaks between the times the fan kicks into high speed. Also when the fan dose kick in to high speed, its already moving so its not as much of a shock. This fan problem affects much of the 05, 06, and 07 Mack trucks. Your local mack dealership should be able to get you the parts for the upgrade, all they need is a little shove in the right direction.

For those of you who would like to know the part numbers for the four individual parts that make up this kit, reply to this posting and ask. I can always post the part numbers tomorow.

There is a down side to this upgrade too. It dose help you go through fuel a little faster.

Thanks,

Kerry