12.7 Detroits blowing radiator hoses due to coolant additives????

Has anybody heard of this before?

We have several fire trucks (97-05 model years) all with detroits, that are regularly blowing radiator hoses. They aren't rubbing anywhere and failing from weak spots, they are fairly new and blowing out in the center area. Almost all of them are the 90* hoses on the bottom of the radiator.

I personally believe it is a pressure problem from a liner or bad head gasket allowing engine compression to pressurize the coolant system. They do have a pressure relief valve of some sort in the cooling system that has been found to be plugged in a couple trucks. However, the diesel shop our central garage uses (for major work) is blaming the additives in the coolant. The coolant filters were being changed every 5-6 months when the trucks went in for service and were being replaced using filters with the strongest additives in them they could get.

 

That was one of the first things the mechanic looked at and they have replaced caps. Most of the hours on them are driving with minimal idle time. The rest of the time, they are stationary and pumping water. We've not had any overheating issues either.

 

The way everything is set up in there, the upper hoses are fairly straight and we haven't had any problems with them that I know of. One would think the rubber would be the same thickness on the elbow where it's molded as the rest of the hose? We've even talked about using a stainless elbow with a rubber hose on either side. We're at a loss right now.

 

Thanks for all the input.

Yes on the OEM hoses. I think the mechanic may have tried a siliconized hose as well instead of a rubber one. I will pass on the radiator/engine mount suggestion. Some of these hoses don't make it 6 months before failing. Would that be enough time for oil/fuel to degrade them? How much contamination would there have to be to cause this?

Most of these trucks get driven 6 and sometimes 7 days a week. I can't see using the strongest additive filters would cause much of a buildup issue, since we dump most of the coolant on the ground when this happens.

I'll keep this updated as we figure stuff out.