John Deere Oil Cooler Leak Question

[Peter_H]

I have a John Deere 410 D backhoe with the 4045T engine. I have developed and external oil leak at the engine oil cooler. I think it's either the gasket or the o-ring between the block and the cooler body. Has anyone else experienced this same type of leak? I'm told other John Deere engines use this same oil cooler so I would be interested in hearing from anyone who had the same type of leak and what you did that corrected the problem. I have attached a picture of the oil cooler unit I am talking about. It is the black unit with the two heater hoses going into it. Thanks.

 

[hosspuller]

Like others have told you already. Clean the area and determine where the leak is. Then take the oil cooler off and replace the gaskets. I would suggest using Loctite #3 to seal the gasket surfaces. It was a suggestion from the HEF brain trust that worked for me.

 

[Peter_H]

Thanks! I will use the Loctite #3.

 

[Peter_H]

Update on leak: Removed the engine side cover and cleaned the area with Brakleen. Started it up and found no leaks. Ran it for about 10 minutes, still no leak. Put a big piece of cardboard under the engine bay and shut it off and went to the house to have a cup of coffee. Came back 20 minutes later and found oil drips on cardboard. Hydraulic oil. There is a steel pipe that comes off the hydraulic pump. Attached to that is a 35 inch long hose about 1 inch in diameter. Both ends are leaking at the joints and running down the hose. I tried tightening them and found them to be very tight. I checked the parts diagram and each end of the line has an O-ring. I'm suspecting that the o-rings are leaking. Also found that the hose might have been replaced as it has a manufacture date on it of 2006, but the machine is a 1995. I think I am going to order a new hose and O-rings and replace it all new. I'm thinking that if the former owner replaced that hose with something aftermarket, then the mating surfaces where the O-rings go might not be sealing properly. I hope the new parts take care of it. Will post my progress when the new parts come in. Anyone have any thoughts on the issue with the aftermarket hose? Maybe replacing just the O-rings? I have to take it apart to replace the O-rings anyway, so why not just replace it with a JD hose.

 

[Tinkerer]

I think you are right about an aftermarket hose and the possibility of the wrong fittings on it. It would be best in your situation to go to John Deere dealer for the new hose. There will be less chance of getting a hose with wrong ends on it. Don't take the old hose and let them match it. Just measure the length of the old one including the fittings.

 

[Delmer]

You can get a cheap kit of o rings and have what you need on hand. The fitting probably got twisted or came loose and the o ring got pinched. Or, like you and Tink said, all bets are off when something's been messed with before.

I'd at least take it apart and see what the o rings look like. A new hose seems like a waste to me if it's not needed. I don't think aftermarket will make one bit of difference with an o ring face seal.

 

[hosspuller]

Since it's leaking at both ends I would suspect the PO either didn't replace the O-rings and/or used the wrong fittings. (Can one thread a JIC fitting to a ORFS ?) Take the hose off to make sure the fittings are ORFS. If yes, then merely clean & replace the O-rings (with proper rings) Don't try to get a "will fit" o-ring. Likely the cause of your troubles. Durometer and size of the o ring is critical to filling the slot and maintaining the seal under pressure.
My own experience of reusing an old O-ring tells the story. I reused the 20 year old ring with a cap as I worked on a transmission. I was just capping the line while it was disconnected. With no pressure, the fitting leaked. With a new o-ring, the fitting is dry while working.