limerocket

Roman, The only reason for the res cap to be off is to be able to fill the system while air is purged and that no pressure is built up to spray fluids all over the place. Re-read my initial post and realize that the stream out the bleed should be constant shortly after the t-stat opens indicating the radiator circuit is full, at which time close the bleed, shut the engine off, put the cap on and you are done. There is no need to run the engine hot enough for the fans to turn on while bleeding. Eventually you will be able to squeeze the upper hose (cool) and not hear air sloshing in the vicinity of the bleed elbow. Small amounts of air will get purged to the res. Good luck.

roman944

Got it. That's kind of why I had trouble with Clark's way of describing this. I only watched this done once by Jim *(shiners) and that was around what, 3-4 years ago ... a nice step-by-step makes things that much easier.

Seems like we have to double check things a lot during this whole rebuild. But it's not bad. Do things wrong, make a thread, find out why, bookmark the thread for future reference + learn from the mistake what was done wrong. Boom. Done.

lol

smokin_944

Roman, the Series 1 car is the one I know best. First the gauge. When the needle gets to the first hash line, you have 80 degrees C. The middle mark is 89 C. The third mark is 97 C. Next thing. Depending on your thermal switch and you have four options, the primary or driver side fan will come on in slow speed. Low temp switch, 823.959.481 E, the primary fan comes on at 65 C. The next one, 823.959.481, comes on at 75 C. The third, 823.959.481 D, comes on at 82 C. The last, 823.959.481 F, comes on at 92 degrees C. Those are the options for a Series 1 car. Based on the temp gauge in the car, you should be able to tell which switch you have. Or, you could check the stamp on the thermal switch to identify it.

smokin_944

The second fan, condenser fan/passenger side fan goes on in a high temp condition which you are experiencing if the gauge hits the third mark 97 degrees C. If it doesn't go on, first check fuse number 5 in the secondary fuse box (the box above the main/relay box at the driver's feet). That is the fuse for the passenger side fan. Do a visual check, maybe put a meter to the fuse to ensure it is good as those fuses are iffy at the best of times. If the fuse is good, go to the next step. Disconnect the passenger side fan and connect it to a 12 volt DC power source. If it works, you know the fan is good. You have eliminated those 2 possibilities as problems.

roman944

we had to fix one of the connectors on the fan switch, both fans work now

it's kind of raining on and off, so I'm waiting for a clear spot to do this the right way!

944V8inDFW

One tip to help get air out 944 or anything else for that matter, turn on the heater to full hot position fan on low. Coolant circulates in the heater circuit first until the stat fully opens. On the 944 to open the heater circuit manually you can disconnect the vacuum to the heater valve.

roman944

ok well, the fans now ...

passenger's side comes on - high speed

driver's stays off

now when the temp got REALLY hot (past 3rd mark on the gauge) - driver's side turned on

when I turned the car off, the fans turned off too

something weird is going on

CorsePerVita

If I recall... (i may be off a little) but the drivers side fan is controlled by the thermoswitch. My fans run in lowspeed sometimes, but once my thermoswitch kicks in the driverside fan on mine kicks on full blast.

Question - when the fan kicks on does the temp go back down? i'm assuming the bleeding went well?

roman944

well, we are still trying to get the bleeding technique under control

we just did the first cycle now

started the car, cap is off, bleed is open, waited for temp to get to half, and closed the bleed

waited for fans to turn on - after maybe 20 secs open bleed again for maybe another minute

then turned the car off

temp seemed to hover around 3rd mark though

maybe my fan itself is bad (motor or w/e)?

CorsePerVita

rarely does a fan go bad. usually is wiring, or a switch that is failing.

is it still spitting at you and coughing air when you open the bleeder or is it consistent coolant? i had an issue with my hovering around 3rd mark because of a crappy aftermarket thermostat.

if it's hovering at 3rd mark either the fans aren't turning on, or there is still air, or there's a flow issue.

once the fan turns on the temperature should return to half or just a bit before half, but should stay there. if the fan turns on and the temperature does not drop and does not change and climbs then there is still air and/or flow issues. you could try jumpering the fan using a connector. the point of the thermoswitch is to complete the circuit at a temp. if you jumper the wires it connects to (completing that circuit) and the fan turns on it is the switch.

before we assume anything is wrong with the fans/switch there must be no air in the system so that is not a variable.

cb951

A few years back I had some cooling system issues and, in trying to bleed beyond a shadow of a doubt, I tried various methods as described in the manuals, Clark's, and numerous posts on RL and elsewhere. While I was consistently able to get a steady stream of coolant from the bleed screw (through many cycles and over several days), I still seemed to have air in the system (at least the symptoms were there). When I tried to bleed with the cap off of the reservoir, once the engine was up to operating temp, coolant began to pour violently from the reservoir. Is that normal? Did I continue too long once the engine warmed?

In the end, I bought a vacuum bleeder (about $80) to use with a very small compressor. It worked perfectly and easily. Best tool investment I've made.

roman944

well, we think that we got it to where there was just fluid coming out, so we stopped, and temp was on a 3rd mark

but my fans are not turning on at half-mark

so we are really not sure, my dad and my brother think that the relay for the fans might be bad or giving up, so they are saying that I should get a new one, and then the fans should turn on at the right time (at half mark)

once the fans are on, the temp appears to stay at the 3rd mark and not get "hotter"

choinga

what's the best way to use a vacuum bleeder? I bought a second hand unit but haven't used it yet. But, I think I may need a re-bleed as I'm noticing some weird temp gauge issues (although mine never really gets up past half way even in the hottest scenario...but it usually hovered around or slightly above the 1st mark).

Did you warm the car up first or just attach it, pump it to pressure (i've read no more than about 12-15PSI) and open the bleeder screw?

CorsePerVita

confirmed with my car... my driver side fan is hooked to the thermo switch. /could/ be a relay. but you should be able to jumper the wires on the thermoswitch to determine this. you have some alligator clips? connect to the two wires on the thermoswitch (looks like a plug in the radiator with 2 wires hanging out of it) - if you turn the car on and the driver side fan IMMEDIATELY turns on then it means the thermoswitch isn't kicking the fan on. If you connect the wires and it does NOT turn them on then yes, it would be relay related. Again, the job of the thermoswitch is to open and finish the circuit once the coolant heats it up to a specific temperature.

If you got the air out and the system cools down once the fans turn on, but they turn on late then it's more likely switch related.

cb951

With the engine cold, cooling system empty, and heat turned on, apply the vacuum to no more than 12-15 psi (don't want anything other than hoses to collapse under vacuum). Then, as per the vacuum bleeder's instructions, fill the system with a 50/50 mix (or whatever you want to use). Theoretically, the coolant mix will enter the system which is in vacuum (no air). Then disconnect the tool. If there is still some vacuum in the system (pressure less than atmospheric), some air will enter the coolant reservoir. As long as there is a sufficient coolant level in the reservoir, no air will enter the rest of the system. Most likely, enough coolant will enter the system in vacuum so that there is no longer any vacuum in the system. When you disconnect the tool, you can just top up the reservoir, if needed. I ran my car this way for a couple days with no issues, but then bled the system in the usual way just to be sure. I don't think that was necessary. Using the vacuum tool resulted in the only time I ever felt sure that the system was air-free.