Red pipe, blue knob leaking under kitchen sink

[IknownothingDIY]

Hi all, the pic below shows the pipe under my kitchen sink which leaks (but only at night) about half a bowl of water. It seems tight so not sure how it is leaking. Can I fix this myself? I assume the blue knob is on “closed”, would turning that knob help possibly?

Thanks

 

[jj4091]

Blue knob is in the open position You probably need a new washer in the hose attachment

 

[Fred Blogs]

The blue knob is in the on position. Those types of isolators can leak from the spindle although looking at the connection tothe brass pipe that is corroded so is possibly leaking as well. Turning the blue knob to the off position will not stop the leak unless it is coming from the plastic connector which also are prone to leak. There is a fair bit of diagnostic work to find out what is leaking and the reason it only seems to happena t night is because the pressure will have been built up with no water usage.

 

[terryplumb]

The 3 places that leaks can develop ..
1. Where the copper pipe connects to the valve .
2. From the spindle below the blue handle.
3. The hose connection to the valve ( white plastic bit)
You need to tell us which it is ,all 3 are relatively simple to cure.
There doesn't appear to be any water showing in your pic ,are you sure the leak is from that area ?