I've done some recent work on my 92 Accord in which the cooling system has been opened up and some coolant released, and I'm aware of the importance of bleeding all air out afterward during the refill process. I know about the bleed valve on the thermostat housing and how when refilling the coolant into the radiator that valve should be opened until a steady stream of coolant is visible, which should indicate the system is full and any air in the system should have been expelled through that valve when opened. Also I realize the heater valve should be opened all the way when refilling so that an air pocket will not remain in the heater core/circulation.
I've read that some suggest parking nose up on a hill or perhaps putting the front of the car on jackstands while refilling also, apparently to help any air bubbles in the system to rise to the highest point and be released out of the open radiator neck.
My inquiry here whether you can actually rely on bleeding all the possible trapped air in the system be merely opening the bleed valve while refilling, without raising the front of the vehicle (car on level ground)? My guess is it really wouldn't be reliable because the bleed valve isn't really the highest point in the cooling system?
Some of the work I did was the removal/replacement of the fast idle control thermo valve and the idle air control valve, both of which coolant circulates through, and those look to be definitely higher than the the bleed valve on the thermostat.
Also, I was considering getting one of these "no spill funnel" kits, maybe to make it easier and perhaps a more sure method of removing all potential air pockets in the system:
Lisle/Spill free funnel (LIS24610) | | AutoZone.com
Here Eric the Car Guy is using one too, and mentions how nice these things are to do the job:
I suppose the kit isn't a necessity but I was just fishing for comments here whether by using the funnel kit method might be a more sure-fire way of knowing all the air has been purged. Or is more or less just a gimmick and doesn't really make the air bleed process much more reliable than not using it (for the 92 Accord engine anyway)?

 

As long as you are on level ground and not parked with the nose downhill, the top of the radiator is the highest point in the system.

I have used this funnel for bleeding air out. You can just top off the radiator and use a turkey baster when the coolant expands.

You should get most, if not all, air out of the system. Any remaining air will work itself out from normal driving. I have never jacked up the front of my car, or used that spill-proof funnel and never had an idle problem from changing coolant.

 

I would also like to add to PAhonda's post, which I pretty much agree with.

Most of the air purging also happens after the thermostat has opened. When it opens, you normally start seeing big pockets of air start to come out. You can also feel the lower radiator hose to see if it has gotten hot to indicate the thermostat has opened; but, be very careful while putting your hand down there while the car is running.

I have the Lisle no-spill funnel and like it a lot; although, I never had any major problems bleeding air from cooling systems without it. Having a funnel like what PAhonda shows in his post or the Lisle helps.

 

Dumb question here, but does that funnel at all provide a seal where it inserts into the radiator filler neck? Doesn't look as if it does. Reason I ask is because you mention using a turkey baster when the coolant expands. Do you mean when the coolant expands up into the funnel? I don't quite follow. The obvious advantage of using this type of funnel (over a regular configured funnel) is the large reservoir and the wide bottom spout, or other additional advantage perhaps?

 

It is cheaper than the spill-proof funnel.

It seals, but not well. When you get an air bubble that splashes coolant, the funnel allows most will return to the radiator.

If you fill to the top of the radiator, the funnel has no coolant. When coolant gets warm, it expands and will start to fill the bottom funnel. I remove that coolant, so it doesn't spill onto the floor.

This was something that works for me.

 

Okay, thank you for the helpful replies.

 

When I did my coolant change I was almost tempted to not buy the Lisle Spill Free funnel but I bit the bullet and did it anyway.

Let me tell you I was SO glad I did. It was probably one of the best tools I ever bought. It's a small investment to remove the headache from changing coolant in the future or whenever I need to (granted this isn't often).

If you can afford it I strongly recommend it. I don't have to juggle coolant I just put it in the funnel and the engine sips if it needs it. If it doesn't I jam the included stick into the middle, pop the funnel off, transfer it to the reservoir and empty the left-over coolant into the reservoir and top it off.

 

Me too. Tempted not to buy it, but did anyway ($25). Bit the bullet.

Those kinds of comments I've noticed are common among the reviews I've read from others also.

I have two cars to maintain, and occasionally will work on others too. So changing/filling coolant isn't often for me (nothing like a shop or anything) but still something I find myself doing enough to maybe make me "investent" in the fancy funnel worth it, if indeed it simplifies the process as is claimed.

Actually my inquiry here I think was to ask whether the fancy funnel kit would be a more reliable method of ridding the system of air than the traditional method otherwise, and it's apparent that is not necessarily the case at all. The fancy spill-free funnel method is more just for convenience sake. Hey I'm usually cheap and hate "wasting" money as much as the next guy, but seems like with the positive recommendations such as those from MessAround I may be happy with the tool and glad I have it.

Thanks

 

Yes I think it's definitely possible to bleed without it but I think it would be far more annoying. I'm lazy so I just want to plop the spill-free funnel on, have it support itself (since it locks on) and just pour coolant into the radiator until it starts to back up in the funnel and then don't add more until the engine sips all of that away.

Probably the reason it's most useful is because it locks in and provides a little space for coolant to go so any situation coolant would normally overflow onto the ground now has a little bucket it can go into. These situations include filling the cooling system (since it's hard to tell when you've put in as much coolant as you can unless you measure how much you're putting in), when you massage the hoses and squeeze them the fluid will push out of the filler neck and when the engine gets warm the fluid naturally expands out.

Oh and another note since the coolant expands into the funnel as the engine warms if you're done bleeding and you cap the funnel and transfer that expanded coolant somewhere else the engine is going to suck that difference from the reservoir as it cools. All this means is make sure the reservoir is up the max line (or maybe a little higher) and check the reservoir the morning after the change. The level should be way down. Just fill it again, drive and keep checking the reservoir for a day or two after the change.

 

Great. Thanks for the further comments.