Community Forums

tigersharkjd · 05-05-2009, 04:00 PM

I contacted Freightline regarding a slobber tube extension kit for my Cummins 425 ISL. I was told this 2007 engine does not have a slobber tube, as it is actually recycled back through the engine. They indicated on earlier ISL and Cat engines there was an issue with the slobber tube venting into the radiator airflow. I called Freightliner because of the many comments regarding over heating and having to clean the radiator, input fans, etc. The simple green application and spraying (no pressure sprayer) inward and outward periodically was recommended, even though I have no slobber tube venting. They indicated that my engine, due to environmental protections will run a little warmer, but should not exceed 215. The downshift on the uphill grades and keeping RPMs between 1500 and 2000 was suggested as a cooling effect. I wanted to just pass on the information I received for my particular situation, as I know this is a much discussed topic.

Gary RVRoamer · 05-05-2009, 07:31 PM

Most ISL's are installed with a side radiator and the slobber tube is not an issue anyway. It is the rear radiator configuration (more common with the ISC than the ISL) that has a problem with spraying the slobber onto the radiator and anything towed behind the coach.

Pigman1 · 05-06-2009, 08:51 PM

The 425-07 engine has a closed crankcase ventilation system, so no slobber tube. It does however, have a filter in that system that has to be replaced periodically. The filter can be seen sitting flat above the valve cover on the transmission end of the cover. The filter has 13 bolts holding the cover on it and can be reached from the bedroom access very easily.

The folks at Freightliner in Gaffney did not have any information on the filter, didn't know where it was, and didn't even know it was a time/mileage change item. This is specified in the Cummins engine book. Furthermore, Freightliner had no filters. Said I'd have to go to Cummins for that.

John

tigersharkjd · 05-09-2009, 05:51 AM

Pigman please post what you hear from Cummins on this filter and the change intervals. Thank you.

Pigman1 · 05-10-2009, 05:55 PM

I have not contacted Cummins yet but this is what I've found in my Cummins book.

The Crankcase filter carries Cummins Part Number 4939749, or Fleetguard CV 5060300. These numbers are correct as I have removed the filter cover on my 425 ISL EPA 07 engine and this is the filter I found in there.

According to our manual, the filter should be replaced each 60,000 mi or 2 years, but under the 80,000 mi or 2 year column, there is also an entry saying the crankcase filter needs to be replaced at that interval. One of these days I guess I'll call Cummins and ask them to clarify the 60,000 vs 80,000 mile issue. Based on my examination of my filter I think these numbers are quite conservative, but everyone will have to decide this point for themselves.

John

powerboatr · 05-15-2009, 09:41 PM

Quote:

Originally Posted by tigersharkjd

I contacted Freightline regarding a slobber tube extension kit for my Cummins 425 ISL. I was told this 2007 engine does not have a slobber tube, as it is actually recycled back through the engine. They indicated on earlier ISL and Cat engines there was an issue with the slobber tube venting into the radiator airflow. I called Freightliner because of the many comments regarding over heating and having to clean the radiator, input fans, etc. The simple green application and spraying (no pressure sprayer) inward and outward periodically was recommended, even though I have no slobber tube venting. They indicated that my engine, due to environmental protections will run a little warmer, but should not exceed 215. The downshift on the uphill grades and keeping RPMs between 1500 and 2000 was suggested as a cooling effect. I wanted to just pass on the information I received for my particular situation, as I know this is a much discussed topic.

freightliner or cummins actually said to use SIMPLE green on the alum radiator?
IMO as a corrosion entity, this seems a bit on the wrong side.
a. most folks use WAY to much simple green or never dilute it.
b. most folks NEVER ever get it all rinsed off
c. the simple green residues will cause hydrogen embrittlement to aluminum structures and the the thinner the metal the faster to fail, especially areas of stress like the alum to copper joints or alum to plastic joints.

d simple green is a great fairly earth friendly cleaner, but it has to be diluted and RINSED and RINSED and RINSED again to get it off with no residue

MonacoMama · 05-16-2009, 09:18 AM

Quote:

Originally Posted by RV Roamer [Gary]

Most ISL's are installed with a side radiator and the slobber tube is not an issue anyway. It is the rear radiator configuration (more common with the ISC than the ISL) that has a problem with spraying the slobber onto the radiator and anything towed behind the coach.

I want to say that maybe "Some ISL's are installed with a side radiator" because I know Monaco Diplomats & HR Endeavors are very popular RVs - and I know for a fact that our radiator is not on the side...and YES ... we have an ISL engine with a slobber tube.

MM

Gary RVRoamer · 05-16-2009, 02:36 PM

Yes indeed, MM. Monaco uses a rear radiator with the ISL in the Diplomat/Endeavor. When they upgraded the engine in the Diplomate/Endeavor from the ISC back around 2004, they stuck with the rear radiator for some reason. Most manufacturers use the side radiator with the ISL cause it needs a lot more cooling and the side rad can more easily meet that need.

I'll stick with my claim, though. I still think MOST coach manufacturers use a side rad with an ISL.