Volvo L70E oil cooler

[Mike L]

About 4 years ago I replaced a faulty oil cooler on this machine. Flushed the system and good to go. Then about 1.5 years ago I had to do it again. Getting oil in coolant. Replaced the oil cooler, flushed the system with cascade until clean and good to go. Got a call today that it did it again. They are buying genuine Volvo (duetz) parts from the dealer and once I get the radiator clean it’s good to go so I know my repair is good but why don’t they last?

 

[funwithfuel]

Have you inspected the relief valves? There should be reliefs integrated to the base iirc. The threaded plugs that bind the cooler to the cover, are you servicing the sealing rings there as well? I do remember a staggered arrangement of viton and teflon rings on those "plugs"

 

[Mike L]

I haven’t inspected the reliefs but I do recall replacing the plate that goes between the oil cooler and the block. Not sure which time that was. I’ll make sure to check it out

 

[funwithfuel]

The other thing to consider? Is it getting by somewhere else? Have you pressure tested the coolers as they fail?

 

[Mike L]

Ok so last week I replaced the cooler and the plate between the cooler and the block that holds the reliefs. flushed it out pretty good and the customer said he’d finish flushing with water. He would fill it with water and run it for the day and drain it in the evening. 5 days it was fine and then it started pushing black oil out the coolant tank and the engine oil is low. I had a short amount of time today and took off the new cooler and plate. On the coolant side the new oil cooler had some slight pitting which seemed odd for 5 days of water in it. I didn’t get a picture of it. I did put air to the oil side and it held so it’s not leaking internally. I think my issue is something else but what? Cylinder head? The machine works in heavy wood chips and sawdust and has been hot plenty of times but I’m not pushing compression out the tank and it doesn’t regularly overheat. Any ideas?

 

[William Stein]

Did

Ok so last week I replaced the cooler and the plate between the cooler and the block that holds the reliefs. flushed it out pretty good and the customer said he’d finish flushing with water. He would fill it with water and run it for the day and drain it in the evening. 5 days it was fine and then it started pushing black oil out the coolant tank and the engine oil is low. I had a short amount of time today and took off the new cooler and plate. On the coolant side the new oil cooler had some slight pitting which seemed odd for 5 days of water in it. I didn’t get a picture of it. I did put air to the oil side and it held so it’s not leaking internally. I think my issue is something else but what? Cylinder head? The machine works in heavy wood chips and sawdust and has been hot plenty of times but I’m not pushing compression out the tank and it doesn’t regularly overheat. Any ideas?

you ever get to the bottom of this issue?

 

[Mike L]

I guess we did. The shop where I had done the repairs didn’t have running water and the customers mechanic was hauling me water to fill the machine with from a different part of the mill. We found out afterwards that he was getting some discharge water from the power plant there which had something acidic in it which I can’t remember now. That would explain the pitting. The last time I changed the cooler we used tap water to flush it and it never bothered again. Go figure.