radiator bleeder valve

rancherman · **Posted:** Thu Nov 06, 2014 9:53 pm

Isn't it supposed to let air out, or at least blow hot coolant out when you open it? (hot engine of course) Half turn out, it comes up about 3/8ths inch.. just as it should.. but nothing is chasing me across the driveway! No- bubbles, no face scalding steam... nuttin-
I read ONE post where the poster said they don't work. Is this valve easy to plug with crap? or is there a safety poppet underneath, for idiots like me trying to do this?

Topan · **Posted:** Fri Nov 07, 2014 2:07 am

Thanks for posting, I have exactly the same issue.

rancherman · **Posted:** Fri Nov 07, 2014 10:00 am

It's been thermo cycled a half dozen times, and coolant level has stabilized in the fill bottle. I put in about the same amount that was drained for my 'stat replacement.
They are 'cross flow' radiators, so the pocket of air should eventually get pushed out.
(through the radiator, and eventually back to fill bottle)
When I first posted this, I assumed the part where the bleeder valve was.. (under the plate that holds down the radiator) was a top tank! me bad. I walked out this morning to see again, and sure nuff.. it's a cross flow radiator. Any amount of air will get pushed ACROSS the tubes, eventually, and end up back at the fill bottle.
Makes me wonder if that valve isn't a 'one way' type FILL valve, where they (at factory) open it, put a rubber connector over it, and fill the system 'backwards'.. Or maybe, just maybe, ours is plugged.
Edit: after reading this ^^^^ I'm still not convinced air can leave the radiator! sure, air will go across the radiator to opposite side, but it must go down to leave..

papaindigo · **Posted:** Fri Nov 07, 2014 10:23 am

Might be a bit long winded but I assume you mean the valve on the left upper side of the radiator when viewed from the front. If so then:
1. to drain the radiator on a cold engine; pull coolant tank cap (effectively the radiator cap); open radiator drain valve (lower left rear corner of radiator when viewed from the front - 2cms off a 10mm Allen key will fit in the center part of the valve for turning ease); when coolant has drained from the coolant tank open the top radiator valve (it can be removed, which speeds up draining, by turning it counter clockwise so the white line on the flange points to 4 o'clock and then pulling straight up - as I recall it does have a tiny internal passage that on a warm/hot engine might or might not allow coolant flow).
2. to refill close radiator drain valve; refill at the coolant tank until coolant starts to overflow at that top radiator valve; "burp" the system by squeezing the upper radiator hose a few times; add more coolant as needed (this gets as much air out of the lower part of the cooling system as possible); reinstall the top radiator valve (if you have removed it reinstall can be a bit challenging - look carefully at the flanges on the stem and in the hole-align-turn clockwise while pushing down); complete coolant fill at the coolant tank to ca. .75-1" above the mid-line; after about 3 drive cycles from cold>hot>cold recheck the cold coolant level which should have dropped back to the mid-line as air is purged from the system via the overflow/degas port on the tstat housing.

Hexus · **Posted:** Fri Nov 07, 2014 11:02 pm

The whole thing that you're talking about pulls out to bleed through. You don't remove it part way and let gas escape, but remove it entirely.

rancherman · **Posted:** Sat Nov 08, 2014 12:23 am

Hexus wrote:

The whole thing that you're talking about pulls out to bleed through. You don't remove it part way and let gas escape, but remove it entirely.

hmmm.. ok then!
turn it out till it hits the stop.. (about half turn) and pull it straight up? or continue turning it all the way?

Topan · **Posted:** Sat Nov 08, 2014 4:13 am

Papaindigo, can you confirm that for bleeding the circuit, the bleeding valve must be taken out or only twisted up opened?
Thanks

papaindigo · **Posted:** Sat Nov 08, 2014 10:34 am

The system will drain without doing anything to that valve but draining that way is likely to take a very long time based on what I have seen. If you remove the valve, after letting the coolant tank on the firewall drain (see my earlier post), by turning it counter clockwise so the white line on the flange points to 4 o'clock and then pulling straight up draining speed very noticeably increases. I presume because the system is more effectively opened to atmosphere. I simply don't remember the details of the valve well enough to comment on whether just turning it would be as effective. Best I can say is just turn it and see what happens to drain speed; if drain speed significantly increases there is probably no need to pull the valve but if not I'd pull the valve.

rancherman · **Posted:** Sat Nov 08, 2014 10:40 am

methinks a lightbulb just went on here...

Is that valve for draining purposes? which means there would be a flapper under it to prevent stuff coming out, but allowing air in for the 'vacuum thing' part of draining a radiator.
Insert: Chryslers safety crew looking at this little valve, and demanding a failsafe for future lawsuits... Otherwise, there'd be warning stickers all over that valve "DO NOT OPEN WHILE HOT".

Which makes sense now, another poster (Hexus) said to remove it entirely for letting air OUT
Thanks Hexus, Papaindigo.

radiator bleeder valve

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