Oil cooler leaky hose

[Perrin21]

I have changed my oil cooler as it looked like it was leaking, however I have noticed the leak may be coming from a small hole with a ball inside on the hose fitting. What is this for? Is it some kind of release valve? Why would it leak?

 

[MarkTurbo]

Does the small hole look like the one on the nut in this picture?

Its actually the stainless steel pin that attaches the nut to the fitting so it won't be leaking from there, does the nut spin freely or is there any damage to the seat in the fitting?

 

[Perrin21]

It all looks ok at first glance. Yes the pin looks like that. Nothing seems loose.

 

[skiddusmarkus]

Is the fitting like the one above ie a barbed type that you tighten with a jubilee clip?People have had these leak and I seem to remember an engine fire caused by a cooler using these fittings over the cam cover.
The screw on type are a better choice.

 

[Perrin21]

No it's a thread tighten. But the small pin is like the pic. Im told they are Goodrich hoses

 

[MarkTurbo]

The picture I posted above is just a random brake pipe fitting I used just to show the pin in the nut.

Are your oil cooler fittings like these?

http://www.demon-tweeks.co.uk/motorsport/aeroquip-goodridge-hose-fittings/goodridge-female-hose-end-fitting-2