Author Topic: CAC Cleaning on Cat C7 in Tiffin Freightliner  (Read 5292 times)

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Offline ambr607

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CAC Cleaning on Cat C7 in Tiffin Freightliner
« on: March 04, 2017, 06:57:55 AM »
New around here and have been reading up on maintenance.  My slobber tube vents aft of the radiator near the trailer hitch (the bugs don't stick to my trailer or toad!) so I think I'm good there.  On the Phaeton the radiator shroud makes it impossible to see what's accumulating on the forward face of the radiator and, I assume, the CAC.  Most here recommend cleaning the CAC at least annually.  How do I get to it?
Thanks, Steve
2006 Tiffin Phaeton with Cat C7, Freightliner

Offline Brett Wolfe

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Re: CAC Cleaning on Cat C7 in Tiffin Freightliner
« Reply #1 on: March 04, 2017, 08:41:15 AM »
Steve,

Welcome to the Diesel RV Club.

Indeed, coach makers make accessing the front of the CAC a challenge. An example of where the interior designers over-rule the engineers.

You should have some access from the bedroom or closet.  NO FUN.

Offline ambr607

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Re: CAC Cleaning on Cat C7 in Tiffin Freightliner
« Reply #2 on: March 04, 2017, 01:00:59 PM »
From the closet access I can get to the top of the radiator but to get to the core would require removing the expansion tank and fan shroud.  The shroud blocks all access from the top.  From underneath I can see the bottom corners through the fan.  Very limited but what I can see looks pretty clean.  Am I looking at the CAC or the radiator here?  I can't tell.  If they're stacked then spraying from the rear won't do much.

Another note from poking around down there: the water pump drive belt has far more slack than I like but again, I can't see or reach a tensioner.  I can see the belt coming down from the pump pulley to what appears to be an idler (maybe the tensioner) and then disappears on its way down to the crank pulley.  Am I guessing correctly that replacing the belts on this beast requires dropping the radiator?!?  At 60,000 miles/11 years on original coolant, hoses, belts should I do more change the coolant and hoses as a preventative measure?  I think you've mentioned fan bearings and the water pump if I remember correctly from other threads.  The more I read the more I'm leaning toward a Super C next time for ease of access and on-road safety of a full truck cab.  I love the space of the Phaeton DP configuration but... the gripe list is growing!
Thanks, Steve
2006 Tiffin Phaeton with Cat C7, Freightliner

Offline Brett Wolfe

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Re: CAC Cleaning on Cat C7 in Tiffin Freightliner
« Reply #3 on: March 04, 2017, 02:09:52 PM »
You have a SANDWICHED cooling system:  The CAC(Charge Air Cooler) is in front of the radiator.

So, the fan pushes air through the CAC and then the radiator and the air exits the back.

90% of the dirt is on the FRONT of the CAC.  It can be accessed only from the front of the fan shroud. Most coach makers left you some access from the top.

The water pump belt (a V belt) is on a manual tensioner.  The serpentine belt is on an automatic tensioner.
They can be replaced without removing the CAC and radiator, but it is a "not fun" job.

And, a slipping water pump belt will allow the engine to overheat, as will a clogged CAC.