Community Forums

discovery39s · 06-24-2018, 04:46 PM

This should get you there.
http://www.irv2.com/forums/f26/rear-...ng-324747.html
I hope!

caninecop · 06-25-2018, 07:53 AM

Quote:

Originally Posted by discovery39s

Canine,
Are you referring to the cleaning or the hatch? I posted a detail on this subject I believe last year, spring. I'll look it up for you and provide a link(soon as I figure out how to do that) stay tuned.
George

I was referring to the hatch, I would like to be able to clean between the CAC and Rad. I saw your post this morning on how you did it, thanks for the information

I will look, I think I remember seeing a post on how to do this with pictures. I do better work if I have pictures to look at.

FIRE UP · 06-25-2018, 10:28 PM

Well,
All I can say is, you boys that can get your CAC and radiator clean while THEY'RE STILL IN THE COACH are pretty lucky. If you look at what I pulled/cleaned out of my radiator and CAC the second time I had it all out, (about 4-5 months ago) there is no possible way I could have ever got what you see, out while both were still in the coach. Even if I did have the infamous "hatch" cut into the top of the shroud. My radiator sits right close to about 2" from my CAC so, getting any form of a nozzle in there, with accuracy and efficiency is impossible.

In our coach, with its removable rear grill, it's not all that hard to remove both the CAC and radiator. If I wanted to kick myself in the butt, I could probably have both out in right close to 2 hours. Then, it's a WHOLE lot easier for efficient cleaning. And, I get to play around with all the belts, hoses, tensioners etc. for wear and tear. Done all that twice in the seven years of ownership, not very hard.
Scott

JPO1980 · 06-29-2018, 10:41 AM

Don't know about other engines but my C7 temp gauge would consistently but slowly cycle between the 10 and 12 position , about every 45 seconds, even on flat ground doing 62mph.
Saw on previous posts that this can indicate it's time to change the temperature regulators (CAT term- thermostats to regular people) .
Did that and she has run steady since.
Good luck

Sent from my SM-G900V using iRV2 - RV Forum mobile app

JLWoodward · 06-29-2018, 12:51 PM

Quote:

Originally Posted by FIRE UP

firedoc,

What you've been experiencing is NOT normal for the C-7. That exact issue's been discussed a few times but, not lately. I have two friends with the same exact temp swing as you do and, I have others that have the same almost exact coaches with ZERO temp swing and, the same engines. I've forgotten just what the cause was but, on a few I've read on here, it's correctable. Our coach, an '04 Itasca Horizon 36GD with the C-7 330HP CAT, is right steady at 185 for about 90% of its operation. It will climb some when ascending grades, depending on the grade, outside ambient temp and more.

I've recently put in new thermostats, water pump, belts, hoses, and, thoroughly cleaned the fins on both the radiator and the CAC. The engine used to run at a constant 194, + or -. But, with all the new stuff and t-stats, it runs down the road at 185 with no swings.

Scott

P.S. I'd have to look around some but, I think I could find what the cause of the C-7 temp swings was.

My cat c7 stays at 185 all day long. Will only climb on grades up to 200 maybe. Runs very cool. C7 has 2 thermostats in the housing and if one is sticking will cause what you see as only open doesn’t give enough flow to maintain temp[emoji481]

FIRE UP · 06-29-2018, 02:50 PM

Quote:

Originally Posted by JPO1980

Don't know about other engines but my C7 temp gauge would consistently but slowly cycle between the 10 and 12 position , about every 45 seconds, even on flat ground doing 62mph.
Saw on previous posts that this can indicate it's time to change the temperature regulators (CAT term- thermostats to regular people) .
Did that and she has run steady since.
Good luck

Sent from my SM-G900V using iRV2 - RV Forum mobile app

Quote:

Originally Posted by JLWoodward

My cat c7 stays at 185 all day long. Will only climb on grades up to 200 maybe. Runs very cool. C7 has 2 thermostats in the housing and if one is sticking will cause what you see as only open doesn’t give enough flow to maintain temp[emoji481]

Thanks to both of you boys for posting that info on "cycling" C-7 engine temps and, the remedy to correct it. I was pretty sure it had to do with the T-stats but, I wanted to make sure before I came back and stated it. Thanks again.
Scott

JLWoodward · 06-29-2018, 06:00 PM

Quote:

Originally Posted by FIRE UP

Thanks to both of you boys for posting that info on "cycling" C-7 engine temps and, the remedy to correct it. I was pretty sure it had to do with the T-stats but, I wanted to make sure before I came back and stated it. Thanks again.

Scott

No prob. Cleaning the cac was also good advice, if you haven't had the mod to move the breather aft if blows oil which is sucked up into and coats radiator. Then all the dust sticks to it and starts building up. Soak aft side of radiator and front side of inter cooler as best you can with a degreaser , let is soak in for a bit then rinse out with garden hose. I do this once a year

FIRE UP · 06-30-2018, 11:02 PM

Quote:

Originally Posted by JLWoodward

No prob. Cleaning the cac was also good advice, if you haven't had the mod to move the breather aft if blows oil which is sucked up into and coats radiator. Then all the dust sticks to it and starts building up. Soak aft side of radiator and front side of inter cooler as best you can with a degreaser , let is soak in for a bit then rinse out with garden hose. I do this once a year

Yep,
I've not even tried to clean the radiator and CAC while they're both still in the coach. I just pulled both of them and did the job outside the coach. As for the blowby tube, yep, I extended that about 10 minutes after we got the coach home for the first time. Its exit is all the way past the rear body.
Scott

Finance · 07-10-2018, 03:46 PM

To give some closure on this Cummins/Freightliner issue, I did eventually speak to the FLCC help line, who say it's normal.

I'm always in favor of due diligence, so I got the part number 9804088 off the Horton clutch. Which is, according to Horton, a variable speed viscous clutch, PWM controlled. As someone with experience in industrial controls, if the best the programming can do is a 25 degree oscillation with that technology, that's sloppy work. Some future date when time permits I'll find out if that's FLCC or Cummins providing the control circuit to the clutch and send in a suggestion to reassess that bit of coding.

Thank you all for an enlightening discussion.

JLWoodward · 07-11-2018, 06:30 AM

Cummins uses those computer controlled viscous clutches on the 6.7 ram trucks also. Been several part number changes for improvements to them at least on my truck. But viscous clutches will wear and leak the fluid then they don’t cool well. So maybe it’s normal or maybe it’s worn a bit ? But imo issue with the viscous clutch design is the setting which they turn on max cooling is fairly high which will cause exactly what you are seeing. Big temp swing, so unless it is grimy or showing signs of leakage I’d say it is good. But check that part number and search on line. May be newer improved models of it available if you feel like doing that. I put newer vesion In my truck and it fixed my temp cycling and air conditioning issues.

TomandGloria · 07-11-2018, 06:46 AM

Had the same questions about temp swing and discussed with Freightliner Tech at Newmar International Rally in Gillette a couple of weeks ago. He told me this was normal operation and that temp swing was within tolerance. I’ve climbed thru the Rockies with temps as high as 214* before fan bringing the temp down to 193*. I was concerned about temps but again was told this is normal and the way the system is designed to work.

FIRE UP · 07-11-2018, 11:14 AM

Hmmmmm,
Kinda wonder, why Cummins specs a fan clutch in a rear radiator application but, NOT CAT. Now, maybe Freightliner has something to do with the decision or not. Every CAT 3126 and C-7 that I have ever had the pleasure of either working on or driving etc. did not have any fan clutch. Maybe either CAT or Freightliner doesn't or didn't feel the need for it, but Cummins or, Freightliner did feel the need for it on a Cummins. Hmmmm.
Scott

pff54p · 07-12-2018, 06:14 PM

Cummins does not install the fan assembly. That is Freightliner, Cummins just supplies the engine.

FIRE UP · 07-12-2018, 10:44 PM

Quote:

Originally Posted by pff54p

Cummins does not install the fan assembly. That is Freightliner, Cummins just supplies the engine.

Hmmmm, Freightliner installs them on Cummins, but not CATs. Well, at least when CATs were being used anyway. I mean, a diesel engine is a diesel engine. They both run maybe close to the same temps, given general conditions being the same. They both burn about the same amount of fuel, and, within at least some specs, they're almost equal. So why a fan clutch on one, but not the other, if both are in a rear radiator scenario?
Scott