400 ISL Transmission fluid in Coolant?

If you do need a radiator give these guys a call or ask them what you have, this is where I got mine.
http://www.radiatorsupplyhouse.com/ads/radsupplyflyer12-08.pdf
JR

Location of the transmission cooler is up to the chassis maker.

So you will find those integral to the radiator and those that are stand-alone.

FossilHound wrote:
Hi,

We have a 04 Dynasty with a 400 ISL, side radiator and 6 speed transmission, just passed 48k miles. Had the unit in for service and pink fluid was discovered in coolant tank which was transmission fluid. I am now informed that we have to replace the radiator. Any thoughts?

Too many different answers as to whether the transmission fluid is cooled at the radiator or not. Just make a phone call to Monaco or Cummins and ask the professional people, not in this forum if you want the correct answer.

I have a 400HP ISL with the Allison trans also, the radiator does NOT have a trans cooler inside. The trans cooler is a heat exchanger mounted inboard of the radiator on a large diameter radiator hose (4"-6" dia.) I just changed my radiator last September and went thru all that equipment. FYI my coolant is red in color!. PM me for my telephone # if you want more info or pictures. Bill

I have just one comment to make which might just apply in your case. To determine if water is present in oil (any oil) just put a few drops on a hot plate. If there is water present it will spit and sputter like putting raw French fries into a deep fryer. No spit and sputter, no water. This test is so sensitive that it will detect water in amounts so small that a lab can't even measure the amount. The lab result would be reported as "trace" amount.

Trans coolers can be integrated with the radiator or separate and both use engine coolant to remove the heat unless it is an oil to air type cooler.

Here is a thread about this type of failure:

http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/21734679/srt/pa/pging/1/page/1.cfm

First of all you probaly will not have to replace your radiator but i hate to break the bad news but you will probaly have to have your transmission completely rebuilt. BUT... before we jump to conclusions lets look at some possibilities and possible steps to take to eliminate futher damage. Drain your tranny fluid first and look at the top of the dipstick for rust, if there is a red looking milk shake in your coolant then there is coolant in your tranny fluid because your tranny cooler is mounted to the left or right side of your radiator depending which way your looking at it. I went through this three years ago, been there done that, not fun. Don't drive the coach anymore untill you have the tranny fluid tested, once tested if coolant has contaminated the tranny your in for a rebuild especially if the coolant has saturated the friction plates which a Allison shop would be the best to take it to for a partial tear down just to analyize the damage. Keep in mind that the cooler is a separate part from your radiator even though attached and if the cooler has a pin hole or small crack this does not mean you need a new radiator but if the radiator is in bad shape this is the time to replace it. Good Luck, i will be in and out the next two weeks but will try to help you if you need it.3708

I don't have your coach, but in my coach and all diesels with side radiators, the transmission cooler and engine radiator are separate. In cars, the transmission fluid is cooled on the bottom of the engine radiator, so the fluids can mix if there is a leak. No so with separate radiators. Bottom line is I have no idea how your engine coolant was contaminated. Could someone have added the wrong coolant to your engine? The different Cummins coolants are color coded and can't be mixed.

Dale- you are correct. And water will kill the trans quickly. A friend of mine bought a flooded vehicle after Katrina and didn't think water could get in the trans. About 500 miles and trans was shot. The fluid looked like strawberry milk. We took the old one apart and all the fiber clutch disks were almost down to metal.

To OP. you could drain a little and you might see it but I would definitely have trans fluid tested and/or flushed.

Not sure it this applies so correct me if I'm incorrect.

When going down the road I suspect the transmission oil pressure is probably higher than the engine coolant when everything is up to normal operating temps and pressures. But once parked the water is still hot and at pressure until it cools while the transmission is not. If there is a leak wouldn't you also have coolant in the transmission?

If I'm right there are a couple of ways to check.
1. Send a sample of the transmission oil out for testing. Even if you can't see coolant a lab will detect the various chemicals.
2. Drain the transmission into a clean container and check for coolant.
3.You could also do a pressure test of the transmission side of the radiator.