Easy Coolant Bleeding
 

I got turned on to this by a fellow who does a lot of work with older BMWs and has the same issue we do with the fill point often not being the highest point in the system.

NAPA has a radiator funnel kit (Part Number 77-4000) that you attach in place of the expansion tank cap, resulting in a large, and tall, funnel sitting atop the fill point.

Simply fill the system until the funnel is full, (over-filling the tank), and then start the engine and let it run long enough to open the thermostat. I just wait until the fans come on low (stock, 92-degree fan switch and the 87-degree Behr thermostat) and then shut the car off.

Then open the bleed screw and let the funnel's height force out the air bubbles with no risk of having more air sucked in.

The funnel has a device to plug it so that it can be removed with minimal spillage and the unused coolant returned to a bottle. You'll have to use a turkey baster or something to get the excess coolant out of the expansion tank, but overall it's a pretty simple process and it has worked well for me. Much better than the "drive, bleed, top-off, repeat" process or using a pressure tester and having to be careful not to let the level in the expansion tank get low.

Thanks for the tip! I might give this a try when I finish my timing belt/water pump/FOES job in the next month, if I do I'll report on the results.

nice tip, gonna buy one too. freakin hate bleeding these engines. takes 8-10 times minimum seems like.

Has anyone tried the vacuum tool on these engines? Or Vac lift, pulls a vacuum on the cooling system then sucks coolant in!

I've always had great luck jacking the front up and opening the heater core before I started.

I fully endorse this method. In fact, ;) I have a home made one - heater hose, funnel and duct tape -;)

However you may overfill the coolant tank and have to remove some coolant with a suction bulb

Never had a problem cracking the bleeder with engine hot and running. Bubbles come out first, then stream of coolant. Done.

Mighty vac on pressure
 

If you have a Mighty Vac: open heater all the way on to allow coolant to free flow through the heater core (heater fan off) open the bleed screw & pack a few paper towels below it to soak up coolant. Remove the reservoir cap ("radiator cap") pull the small overflow hose from where the cap goes up to where you can hook it up to the pressure port of the Mighty Vac and gently press the palm of one hand down over the reservoir fill hole to make an air tight seal. Start pumping the Mighty Vac to pressurize the reservoir. Watch the bleed screw; after awhile of venting air a steady stream of antifreeze comes out (no frothing with this method), close the bleed screw. After putting everything back correctly and tightening everything back up I run the engine & test-open the bleed valve in case there is any errant air (Rasta Monsta style). Seems to work great.

I wouldn't do it with the engine running because if the coolant is flowing the bubbles themselves can be forced through the system and therefore may not be at the high point. Letting the system rest for 30 seconds or so with the engine off lets the bubbles migrate back to the bleed screw point but doesn't give the thermostat time to cool off and close.

This may be more of an issue with turbo models since the bleed screw on turbos is on the side of the elbow at the front of the head, not on top of the elbow.

What I like most about this, as opposed to pressurizing the expansion tank, is that I can leave the vent screw open and flowing for a while (just to be extra sure) without having to closely monitor the level in the tank since the funnel holds about a quart. If I were to let a cup or so of coolant out of the bleed screw with the pressure test method, I'd be risking the expansion tank level getting too low and ending up sucking more air into the system.

It's cheaper on Amazon: http://www.amazon.com/Lisle-24680-Spill-Free-Funnel/dp/B00A6AS6LY/ref=sr_1_fkmr1_1?ie=UTF8&qid=1424207610&sr=8-1-fkmr1&keywords=774000+lisle

Thanks for the tip!

The system is easy to bleed
Engine off, heat left on beforehand
Reservoir cap off
Fill with coolant
Clean the overflow hose end
Put a wrench on the bleeder, hold this in your left hand
Put the overflow hose in your mouth (do not suck!)
Put your right palm over the filler neck
Blow into the overflow hose, pressurizing the coolant reservoir
Open the bleeder, then close, then stop blowing
Inhale though your nose
Repeat until the system is free of bubbles. You can give it one more bleed later when hot and running if you like.

This method works great as long as you do not somehow drink a bunch of coolant, which is poison. So don't.

Damn, knew I should have checked there too! Good find.

I'm trying to imagine being in the position you describe while also being easily able to see both the bleed screw and whether the expansion tank is running low and I just can't do it.

My back gives me enough trouble. The ~$30 is worth it to me not to have to be a contortionist just to bleed the coolant.

I use a Stant cooling system pressurizer,it screws right on to the expansion tank and all you do is pump the pressure to max 15 psi and open the bleeder ... no mess,no fuss and it works flawlessly !
Well worth the $100.00 or so if you do engine work ...
I've pulled the head off my engine a few times and it took less than five minutes to bleed the cooling system each time !

Cheers
Phil

Neither is necessary IMO, I never stare at the end of my wrench once it's seated on the fastener. You probably would not need to top-up the coolant tank and if you did, if the bleeder is closed, the coolant won't fall back out of the head so you could do it half-way, add coolant, and then continue. It's easy. Once it's bled you can fill the tank appropriately.

Really the best method is to jack up the left front of the car, so the chassis is at a 23 degree angle longitudinally, and a 17 degree angle laterally. I then stand on my left foot and pressurize the expansion tank with a nitrogen filled polyprene bladder clenched under my right armpit. While I open the Lindsey Racing Hyper Titanium Gaseous Release Modulator with my free hand and gently kick the bumper with my right foot, an assistant plays an original pressing of die Valkyrie on a 78RPM German phonograph.

Hey at least my method is free. I agree however that a cooling system presser tester is a good tool and if I owned one I'd use it for this. I borrowed one from the FLAPS recently to verify that one of my 928 water pumps was leaking. I pumped it up and she blew coolant like the manneken pis.

Rasta, you're remarks just made me shoot coffee out of my mouth with high velocity..lol:D

Don't forget that the phonograph must be powering a set of Acapella Audio Arts "Made in Germany" speakers. :D

I have done countless 944's never any problems bleeding the system .
not once have I ever had to do any of the things people have said they do to get the air out of the coolant system bleeding the system is just not that hard to do .
at the most you may have to give the car a high idle for a minute to get the air then coolant pumping out the bleeder .

Rasta for the win....