Air in Coolant System? Replaced Coolant Control Valve Issues Refiling

Generally I have no problems filling the generation 2 up It's the generation 3 that can be problematic for filling You want to pour your coolant into the radiator cap the cap with the yellow label on top of it and made out of 10 or silver metal underneath the black and yellow label a real radiator cap not the jug that's behind the radiator but in front of the engine in front of the side of the engine technically we're not worried about that so much yet we're just trying to fill the radiator which will fill the coolant control valve and it's related hosing doesn't matter what ran out when you took the hoses loose that's what's supposed to happen if you were fast enough you would have disengaged the valve from the car chassis slid the three or four metal hose clamps back twist each hose so that they're pre-loosened but still on the valve and then whip the hoses off of the plastic valve one at a time very quickly fitting them to the new valve that you have laying there right next to the inverter pump or wherever you set it down You should be able to transfer those hoses in about 17 seconds to be honest about it I've timed it before I'm not doing anything special that an engineer or a mechanic would not be able to do believe you me and I don't have all the nice tools some of you have so there's always that I have four of these cars we've changed coolant control valves and other pieces in the cooling system without any undo trouble in the southeast United States where it's very hot no issues in any four of our cars with any of the cooling air conditioning and so forth your car should be the same when you're finished I can't see it from here. So now that you're in the middle of this mess all you want to do is slowly make sure that the radiator is staying full leave the cap off everybody thinks we're going to be blowing coolant like a geyser 4 ft out of the radiator cap nothing further from the truth is going to happen with the one NZ engine in this format You don't have to fill it till it bubbles up out of the cap You just want to fill it milk the bottom hose like your milking a cow if you know anything about that and add more water pre-mix 50/50 Asian red or whatever makes you happy and you just keep doing that You want to get all the air out and have nothing but liquid red coolant in naturally air bubbles are going to float up to the top of the radiator cap and come out That's a natural occurrence we're trying to force it to happen a little faster etc. Another trick is just time you fill the thing up if you're in a low crime area and you can leave your hood up just walk away the air is going to find its way out of the highest point of the system which at this point is the radiator cap opening If you're in a big hurry just milk the hoses squeeze squeeze squeeze you know that sort of thing You can see the level in the radiator go down when you squeeze the hoses if you filled it good enough so you can look down in there Don't rush to put a bunch more water or cooling in there let it work its way down Go have a drink smoke a cigarette whatever come back continue adding If you have the capacity on paper for your coolant system for the main radiator well if you're real close to that amount of coolant in Don't force anything You should be in pretty good shape as you're down a few tenths of a quart or something your car is not going to overheat and blow up.

 

there's a ton of youtube videos on how to bleed the engine cooling in a prius (google is your friend) I even have one when I replaced my heater valve. There are lots of ways to do this, from being simple to not-so-simple (I don't see it as hard)

simple method (time consuming):
- set your climate control to max heat, this will allow coolant to flow through your cabin heater
- set car to maintenance or inspection mode (again google it) It's a simple process to let your ICE run continuously
- fill the radiator from the cap (not reservoir tank!) until you see no more bubbles, fill slowly and notice the bubble
- if no bubble and can't take anymore coolant, shut the engine, put back the radiator cap and let it cool down or drive away in your block and park the car, let it cool down.
- repeat the coolant filling process until you see no more bubbles or don't hear any gurgling noises in your cabin.


not-simple since you need a clear hose (quick and do it once)
- set your climate control to max heat, this will allow coolant to flow through your cabin heater
- set car to maintenance or inspection mode (again google it) It's a simple process to let your ICE run continuously
- on the driver side of your radiator there's a nipple for bleeding, insert your transparent hose and loosen the bleeder valve with #6 hex bit or socket. Route the hose to drop the coolant in the reservoir
- fill the radiator from the cap (not reservoir tank!) and check for coolant coming out of the hose.
- continue filling up the coolant until you see no more bubbles coming out from the hose, put the radiator cap back if necessary to prevent spilling and take it out when filling up more.
- repeat the coolant filling process until you see no more bubbles on the hose.
- close the bleeder valve and drive around, let it cool down and fill up reservoir tank if needed.