Slight seep of oil from the cooler (single one on my car) so trying to get the thing out. Can anyone tell me whether that nut on the end of the flexible pipe going into the cooler comes undone or whether it is not a nut at all but welded in place. If part of the flexible pipe it presumably means I have to follow the flexible pipe back to a join then undo it and twist the complete unit to undo from the cooler.

 

Thanks

Hydraulic hoses have a loose nut, which allows the pipe to be disconnected without having to rotate the pipe or other components.

On my S4s this loose nut screws onto a connector which then screws into the oil cooler. At this connection there is a sealing washer. Does this sound like what you can see?

Hi Glyn

 

Yes exactly as you say the connector is alloy. I put so much pressure on the nut  at the end of the flexible pipe that it was starting to warp the oil cooler. This made me think that it was possibly a welded nut and that the whole flexible pipe had to be removed. In the end I sawed through the alloy connector into the cooler.

I read up  on some old threads here and it seems the trick is then to immerse the end of the nut into a solution of caustic soda which will dissolve the alloy and free up the nut. I had a quick try the alloy started bubbling away so will try again in the morning.

Exactly what I did. I used a glass jar which got really hot. Took 3 applications but worked perfectly.

I've done an oil cooler on my car, so do try and save the ends if you can, you don't want to replace the pipe if helped, which is exactly what I had to do. I was able to save the pipe that goes to the other cooler, but the pipe that goes to the engine was knackered, it needed replacing and it's a nightmare job, a manifold replacement is easier!

 

https://www.flickr.com/photos/owengt3/sets/72157629389193265/

Having left the sawn through ends in a solution of caustic soda for about 3 hours all the alloy has disolved and left nice clean connectors which turn freely. Nice result but I am puzzled as to why alloy is used as a connector into the cooler when there is the usual reaction between different metals. 

If anyone is interested.

 

We all know that when doing an oil change that it takes an age for the oil to drain into the sump so that you can take a level reading. But, having changed the oil cooler my car obviously took a bit more oil than usual and in my haste I then developed an oil leak which seemed to be coming from the sump bolts at the farthest end with a hot engine (only noticed it as engine cooled). When I rechecked the oil level after a run and letting it cool down I had overfilled by about a quarter inch on the dipstick.  I let some oil out and the oil drip has stopped. I can only assume that with a fairly shallow sump my oil level was above the sump height. A warning for anyone else doing the job or indeed filling above the full mark.