Freightliner Hydraulic Oil Cooler RECALL

[Woody]

FYI, I just received a memo from Freightliner regarding a recall that some oil coolers on some vehicles may crack due to over pressurization. The oil cooler will be replaced with a cooler that has a higher flow rate and pressure rating. The field service campaign is SF340AB..Call your local Freightliner Customer Service with your VIN number and refer to the campaign number to see if your vehicle is subject to this problem.

[Woody]

FYI, I just received a memo from Freightliner regarding a recall that some oil coolers on some vehicles may crack due to over pressurization. The oil cooler will be replaced with a cooler that has a higher flow rate and pressure rating. The field service campaign is SF340AB..Call your local Freightliner Customer Service with your VIN number and refer to the campaign number to see if your vehicle is subject to this problem.

[The Prez]

Hey Woody: I've got a 330 CAT/Allison Tranny/Freightliner set up on a 2003 Newmar Kountry Star DP. I ordered the coach built to my specs and took delivery 5/1/2003. I'm now on my FOURTH transmission cooler and I've found NO ONE to explain why so many coolers have failed in my coach! Is the cooler you're talking about a TRANSMISSION Cooler?

[Cruzer]

The cooler is for the hydraulic oil, not the transmission oil. Freightlioner had a number of cooling issues with the Freightliner XC chassis and the Cummins 400 ISL. Too much heat for too small a radiator is what it boils down to. They did a few recalls to fix the airflow around it with baffles, etc and they also replaced the Dexron 3 fluid with heavier 15W-40 motor oil so that the hydraulic fan motor would spoin faster once the oil got hot (the lighter Dexron would thin out and the motor would lose RPM).

Now they find out that the heavier motor oil causes the hydraulic oil cooler to rupture because there's too much pressure in it. So this recall fix is basically to fix the last recall fix. It is not related to your transmission cooler problems.

Note that this recall is only for the 400 ISL powered chassis with side radiator. The smaller Cats with rear radiators don't have that problem.

[fidget]

Hi Cruzer,wonder if you know what the symtoms of hydraulic fluid overheat on the 400 isl are.
I have a 2005 using dextron, and because I live in the uk and keep the rv in the states recalls are a special pain.
The freightliner customer service folk simply say get it done but not why in any detail

[Cruzer]

It's not an issue with overheating the oil. The oil is fine and the job that the oil cooler does, namely cool the oil, is working just fine. The issue is that the system originally came with Dexron III automatic transmission fluid in it. Dexron III is a good fluid and didn't overheat in that application.

However, FL has had issues with the engines overheating on the 400 ISL due to the minimal size of the radiator. One of the previous service recalls was to replace the Dexron III with 15W-40 motor oil. Their reasoning is that the motor oil is heavier in viscosity and is better capable of keeping the hydraulic fan motor spinning at the desired speed. They felt that once the Dexron got warm it might thin out and not turn the fan motor at it's full rated speed, therefore not properly cooling the radiator. Personally, I feel that's a stretch because I use Dexron in many hydraulic applications, including some HD construction equipment, with no loss of performance. But that's neither here not there.

The fact is that the heavier oil has popped a few hydraulic oil coolers because they weren't rated to handle that high of a flow with the thicker motor oil, so they leaked. The new oil cooler is about 3/4" longer but it is of heavier construction. It won't cool your oil any better but it will be a stronger cooler and "shouldn't" leak.