limerocket

Pressure bleed - Bottom to top.

CorsePerVita

thanks man. i'm there /once/ in a while. i'm usually on 924board or on 944online but i've found myself here more and more lately since there is an awful lot of trackday guys on here and my 924 is approaching that point more and more every day.

anyway /threadjack.

i'm excited to hear how the bleeding goes for him!

roman944

CorsePerVita (for the lack of knowing your real name) - thank you!

We are going to do this right now.

We went out and got some more 50/50 mix that's good for mix with all antifreeze/coolant - and we are going to do this with your method

I wish I knew about the 1/8" hole before, we would have done that if it makes things THAT much easier

I also was thinking how we are supposed to bleed the system with the cap still on ... lol

I'll report back with the results in a couple of hours!

roman944

oh btw, I was going to ask, is there any way to be able to use that Motive Power Bleeder or something similar for this job? I think I remember reading something along those lines at some point ... not that I have a Motive Power Bleeder ... but that might prove to be a very useful tool to buy in the future!

CorsePerVita

no i made the power bleeder in reference to limes comment regarding the clutch bleeding for the slave/master cyl.

HOWEVER...

If you prefer someone /else/ to do it, some radiator shops have a really neat vacuum system that they can vacuum bleed your entire system bubble free. for a price.

I'm Derek. No worries, hope the bleeding goes smoothly.

Yeah, probably not worth it since you're pretty much almost there. However, for future reference it's a neat little trick for the next time around.

smokin_944

This may be what CorsePerVita is refering to:
http://www.autotestsys.com/Merchant2...gory_Code=COOL

roman944

ah well, you guys can feel free to call me a retard or something, for some retarded idea, I was undoing the allen bolt ... yeah ...

strangest thing though, before, my fans would come on as soon as the needle on the gauge reached half, for some reason, this time, the fans did not come on

new fan and fan relay are in though, and they worked just a few mnts ago ... may still fix itself, we'll see

letting the car cool down right now to give this another shot!

Thanks Derek!

CorsePerVita

depending on when the stat opens and your state of the thermoswitch it may take a moment to come on. the thermostat (if it's stock) i believe opens at about 74C if i recall, so on an early year 944 that would be just a hair before half, but depending on how long it takes to get through the radiator and heat up the thermo switch may be a bit after half, depends. If there is air behind the stat it will take longer to open, too.

With the car off, you can touch the lower rad hose, if it's warm the stat opened, if it's cold it didn't.

roman944

alright, well, now the fan turned on, but only 1, and if I shut the car off, it turns off as well ... but before they would stay on even without the key

something smells iffy ...

thermostat opens when the car is up to temp (fans come on?) then close the bleed screw, but leave the cap open?

or, wait until fluid starts to dribble from under the bleed screw, and then close it and shut the car off, coolant cap still off, and keep topping off the coolant tank?

CorsePerVita

Regarding your fan operation I am going to refer you here - http://clarks-garage.com/shop-manual/cool-01.htm you have an early 944 like mine, and i'm not sure which fan is not running. Check fuses, could be a thermo switch.

Normal operation is for the extra fan to kick on once the thermoswitch kicks on (stat opens).

Regarding the stat/fans/cap thing - what limey was getting at i believe is that if you leave the system open as it's venting when the stat is open it may pull in air. tbh i didn't use specific intervals on my bleeding and it worked fine, but it /could/ pull in air. i'd cap the bleeder before the stat kicks the fans on (before halfway) wait for the fans, give it 10 seconds, then go back at it and keep bleeding. and yes, the cap needs to be open during that process. that cap should be off during the bleeding process.

it'll spurt and sputter and squirt water, if it does, that's air. if it has a constant stream of water, that's no air. and yes, keep the reservoir full when you are doing it.

might take you 1 or 2 thermostat cycles to get it all out of there.

roman944

how long should it take though?

how "open" should the bleed screw be?

seems like the car hovers around the 3rd mark on the gauge

going to test the relay for the fan, not sure why the 2nd fan doesn't turn on, maybe bad fan/motor

roman944

ok, help me out here

1) if I turn the car on - and wait until it warms up enough for thermostat to open and kick the fans on - car is going to run hot ... and at this point, I am supposed to close the bleed screw

but I keep the tank cap off at all times

2) since there are "air pockets" in the car, the car is running hot ... and fans try to cool it down ... but they can't because of air in the system? like the fans won't turn off after a while, because the car is running hot due to air in the system?

so now, once the fans kick on, am I supposed to shut the car off and wait for it to cool back down?

what's the cycle time? because once my fans turn on, they don't shut off ... because the car starts to overheat

CorsePerVita

- turn car on, let it run for a sec (doesn't have to be till the fans kick on, this is just to get it circulating) - open bleeder, get all the air out that you can. (this is with cap off, it should remain off during the entire bleeding process, and you want the coolant reservoir full as well)

- before fan/stat opens (before half mark) close bleeder.

- when fans kick on, stat opens, give it 10 seconds or so to circulate, then crack bleeder and continue bleeding. till no more air. obviously don't let the car get too hot. you don't want it to overheat. i'd turn it off before it hits 3/4.

the idea is to bleed through 1 cycle till you just don't see anymore air coming out. instead of spurting or spitting, it'll just be pure coolant/water. when it's at that point, close the bleeder, turn the car off, let it cool down (so the stat can close), this will let everything settle. then repeat the process.

the bleeder needs to be open enough just to let the coolant/air flow out. you don't want the thing to be so open that it falls out, just so that water starts coming out, if there is air it'll come out in spurts and spit at you a little.

1 cycle means bleeding the system, closing it before the stat opens, opening the bleeder back open when the fan/stat opens for a sec and bleeding it far as you can till no more air comes (or before the car gets hot again, i'd turn it off around 3/4 or before)

The reason it may take a cycle or two is because you'll have air pockets in the radiator, in the block and some hanging out by the pump that are sometimes a pain to get out.

I hope that makes more sense? i am sometimes not so great at explaining things in detail without writing a book.

roman944

yup! exactly what I wanted! way easy

make this a sticky!

CorsePerVita

ok cool, if you have anymore questions post them up and i'll reply or pm me. sorry for the confusion, sometimes i have a hard time explaining things. i am best at attempting to use analogies rather than just talking jargon lol. if you're still struggling with it later let me know, if you're going to be up a while (i see you are in NY, i am in OR) I'll send you my digits and can walk you through it over the phone or something if you're comfortable with that. But I won't be available for a few hours.

and yes, it isn't all that bad, just getting it down the first time you try it is a bit different than your standard radiator where you just leave the cap open and watch it burp lol.