Rep Power: 0

Hello, I have a 2009 civic EX sedan. I popped the hood open today to check things out and I see this hose under the radiator have something blueish color. I think it is not suppose to be there so I need to get a new hose but not sure what hose is this to buy. This is the leak https://imgur.com/a/6SZdq

 
Rep Power: 511

That's the lower radiator hose. That's coolant caking up.

edit:
#10 on the drawing



Part number 19504-RNB-A01 or 19502-RNA-A01. Not sure the difference (possibly different manufacturer), but they both should work the same. Not quite sure why there's a $10 discrepancy between the two. Same part numbers show up for both AT and MT versions of your car.

 
Rep Power: 0

Oh, so for sure it is the lower radiator hose? By the way, thanks for the quick reply. Do you think this is an easy/hard job to do? I cannot take the car to the shop until next Friday.. so hopefully it will not cause me any problem until then..

 
Rep Power: 511

It's a quick and easy job.

Drain coolant
Use a pair of pliers to remove the tension on the spring loaded hose clamps and move them down the tube.
Twist and pull with some elbow grease to remove old hose.
Transfer hose clamps to new tube.
New hose should slip onto hose connections with a slight bit of force.
Use pliers to release tension on hose clamps and move them in place to clamp down on hose over hose connections.
Refill and bleed coolant.
Perform victory dance.

Probably take a half hour or so.

 
Rep Power: 518

If it's been oozing like that, there could be a layer of caked up blue stuff built up between the rubber hose and the fitting......that might need to be scraped/cleaned so the new hose can have a good seal.