Do I really have to drain and fill the coolant, or can I just pop the upper hose off (with a lot of spillage)? After I replace the hose I would burb the system, but I'd like to avoid the whole drain/fill procedure if possibile.

 

What is the best way to replace this hose?

There's no need to drain all the fluid, unless of course you're due for a coolant change. I'd recommend just draining about a quart to half gallon. That should be enough to reduce or eliminate a big mess. Plus, if you drain into a clean container, you can reuse it, or use it to determine how much new stuff you need to add.

 

Why are you replacing the top hose? If it's related to old age, you ought to consider the lower hose too, in which case you'll have to drain most the fluid.

It's leaking, although I have no idea why. I had a whole bunch of stuff replaced (seals, clutch, etc...), and they either missed the upper hose or tightened it to tight and ripped it a little. It's such a small leak I didn't even notice it till I was under the car last oil change. It is leaking where it connects to the block, again very slightly. My coolant level is still good, but it erks me to know it's leaking.

If you haven't identified a hole or rip, it's possible it's just loose. Does it have screw/bolt type hose clamps? If yes, you could just try tightening it a little.

I have replaced the top rad hose on several Subies. I never bothered to drain any coolant. I just loosen up the clamps, and pull the hose off. I first pull the radiator hose. Sure, you will loose a little coolant, but not much. Afterwards, I add coolant, or change all coolant, then burp the system. The little that I spill, I wash off by pouring some water over it.

It's leaking, although I have no idea why. I had a whole bunch of stuff replaced (seals, clutch, etc...), and they either missed the upper hose or tightened it to tight and ripped it a little. It's such a small leak I didn't even notice it till I was under the car last oil change. It is leaking where it connects to the block, again very slightly.

They may have removed the upper radiator hose while doing the work. On my soobs I have noticed the coolant pipe coming off the engine is often corroded under where the hose connects. Sometimes leaving a very rough uneven surface which could promote a leak path.

Sure, you will loose a little coolant, but not much.

 

I dont bother to catch the little bit that spills either.....but I always have been at the shop when I do this work. I dont dare spill coolant at the house. Too dangerous for the pets.

I would drain a bit just to keep the spill to a minimum when you pull the hose off.