I for one do not know the faiure rate of the water to oil units that were used in our coach. Certainly the failure mode, wether it be vibration related, corrosion related, thermal cycle related is not clear. In my conversation with Pacific Power Products they were concerned enough to proactively replace some units before failure. How effective this is and the timing of replacement would normally be related to the cause of faiure and how each of our units is used in real life. With most failure modes one size does not fit all.
What probably makes the most sense is to learn what we can and each of us make decisons based on what is shared. Nobody will know more about these units and the expected life than Rocor. Some questions come come to mind.Why do these coolers fail? Does Rocor have a more durable design that has demonstrated a significantly lower failure rate? Also based on the predominant failure mode has the unit used in our coaches been redesigned to be more durable and if so when?
On the oil cooler page there are several designs for oil to water coolers. The one at the top appears to be pretty robust and has a removable core which begs the question, does that core have a defined useful life and a recommended change frquency or is that to facilitate cleaning if the need arises? Why this design?
http://www.rocore.com/products.htmlRegarding Gerald's comment on metal fatigue with low mileage units failing almost as often as high mileage units, that certainly can be true. If these are internally soldered units, how much solder is in the joint, how well all the surfaces were cleaned and fluxed, the temperature applied and if it caused brittle metallurgy. When soldering, these issues cause defects that will fail somewhat randomly over time just as Gerald observed. The other side of the coin, the one we would want to be sure does not exist, is a design issue where we are getting wearout of these coolers within the normal use life of the coach. That would be a high failure rate, without defects being involved, due to an inadequate design. If that is what we have we would need to know that and make some decisions.
Tim, if you could provide the PN for what was removed I will try and have a conversation with Rocor. What they will share may be a different story. It won't hurt to try and learn what we can. Given the high cost and the lengthy repair to replace the transmission, we would want to know if these coolers experience wearout. If it is random defects only and the cooler normally lasts multiple lifes of the coach then it is just the luck of the draw if you get a defective one and changing one preventatively would not likely improve your odds.
Later Ed