Replacing bypass coolant hose without flushing coolant?
 

I'm installing Cusco engine mounts and while trying to remove the driver-side mount I nicked the bypass coolant hose (Subaru 99078AB210, Toyota SU00303434). It doesn't leak when not touching it, but sprays a thin stream if I compress the hose. I haven't started the engine yet to see how bad it is under pressure.
I ordered a replacement hose (Gates 19922, OEM was out of stock around here) and patched the current one with some plumbers putty, aluminum duct tape and zip ties (not the best plan this close to the exhasut, but it's all I had on hand, and I'm not spending more money on a patch when the replacement hose arrives early next week).

Anyone has some ideas on how to avoid having to flusht the coolant when replacing the hose?
My thoughts are jacking the driver side as high as I can to tilt any coolant away from this hose, having a clean bucket under it when removing the old hose and pouring this coolant back into the radiator (as per the coolant flushing instructions, which I haven't read in depth yet). I doubt I'll be quick enough with removing the old hose and putting on the new one to avoid spilling all the coolant.

I don't think there is anyway around draining the system. I've reused 2 year old coolant without any problems.

Yeah, I'm not too concerned about reusing the coolant. Just don't want to go through the hassle of full drain and refill... I'll report back after I've replaced the hose.

I would be interested to hear how you like those motor mounts. Sorry about the hose issue :(

Make sure it is cool, and plan on working real fast!

Quick update - the patch leaked a drop every few seconds with the engine running. I only drove a couple of miles, and didn't have long drives planned until the replacement hose arrived, but I still didn't like it.

I suspected that the nick in the hose was right where the barb was (since I probably kinked the hose exactly there), so I decided to push the hose up on the barb a little. There's no room on the barb for that, so after removing the spring clip I cut off the last 1/2" of the hose and pushed the hose up the barb. This stopped the leak, as expected.

I did this with the driver side jacked up, and there was still coolant in the hose (leaked a little while pushing the hose more up the barb), so I'm not hopeful about not draining the coolant when swapping the hose...

Replaced the coolant hose yesterday. Raised the driver's side with a jack from the front pinch weld, and put jack stands around the car for safety.

I had the idea to use rubber stoppers to plug the coolant pipes while doing the swap. 59 cents each at my local Ace Hardware. These helped for peace of mind and not rushing the job, but I think that there was little coolant anyway (hopefully thanks to tilting the car) - the pipes didn't leak much after the initial removal of the hose, and most of the coolant the spilled was from what was in the hose itself. I didn't check this (such as intentionally leaving the pipes unplugged), but when removing the plug to put on the new hose it didn't appear to leak much.

Putting the spring clips back was a real pain - the Gates hose is a little thicker than OEM. Lesson learned - slip the clip from the nipple side (while putting the hose on), not the hose side.

Overall I lost maybe a cup of coolant, probably less. I did the bleeding instructions (revving the engine, opening the bleed screw) but saw no indication of air bubbles.