c900 heater core bubble???

I replaced the thermostat in my '86 900, and apparently I have a bubble in
the heater core. The thermostat gets to a nice termperature, but the heat
isn't coming in by me. I'm not seeing the bleeder valve I expected to see
up in that area on or near the firewall, does someone have a procedure
they could point me to?

I used Grunff's suggestion of opening the bleeder nipple on the thermostat
housing, but I'm failing to see how that, being lower than the heater core,
is going to help. What am I doing wrong?

On a side-note, googling for "saab coolant nipple" gives some interesting
results.

Dave "Made you look..." Hinz

Dave Hinz (suffering frozen fingers) wrote:

I replaced the thermostat in my '86 900, and apparently I have a bubble
in
the heater core. The thermostat gets to a nice termperature, but the
heat
isn't coming in by me. I'm not seeing the bleeder valve I expected to
see
up in that area on or near the firewall, does someone have a procedure
they could point me to?

I used Grunff's suggestion of opening the bleeder nipple on the
thermostat
housing, but I'm failing to see how that, being lower than the heater
core,
is going to help. What am I doing wrong?

Only proc I have is to *slowly* refill expansion tank with the engine off
and thermostat bleed nipple open until coolant leaves the nipple. that's
always seemed to work on 900s. Only suggestion is to try what I have to do
on my Subies: run engine up to full operating temp, put heater full on,
park facing up the steepest hill you can find (I've got a handy 1 in 3
road on the farm!) make sure it can't roll away and repeat the bleed
procedure. It's always worked so far. If that doesn't work, all I can
suggest is join your heater hoses together, flush the heater core and see
if it's blocked. (Oh joy!) Cheers

Dave Hinz wrote:

I replaced the thermostat in my '86 900, and apparently I have a bubble in
the heater core. The thermostat gets to a nice termperature, but the heat
isn't coming in by me. I'm not seeing the bleeder valve I expected to see
up in that area on or near the firewall, does someone have a procedure
they could point me to?

I used Grunff's suggestion of opening the bleeder nipple on the thermostat
housing, but I'm failing to see how that, being lower than the heater core,
is going to help. What am I doing wrong?

I've usually managed to clear it by opening the thermostat bleed nipple
and revving the engine - it's the revving that does it.

There was one time when I just couldn't clear an airlock, so I
pre-filled the heater core by connecting one end to a garden hose and
flushing through at high flow. That worked.



--
Grunff

On Tue, 14 Dec 2004 01:39:31 -0500, hippo <johnh (AT) nospam (DOT) shoal.net.au> wrote:

Only proc I have is to *slowly* refill expansion tank with the engine off
and thermostat bleed nipple open until coolant leaves the nipple. that's
always seemed to work on 900s.

I'll try it again. Maybe I didn't have it warm enough and the thermostat
to the heater core was closed; sometimes I don't think these things
all the way through, and sometimes I overanalyze them and trip myself
up.

(I've got a handy 1 in 3 road on the farm!)

What is a 1-in-3 road? I've never heard that term before, but I do have
30 acres of land with hills. Is this a "slope of 3:1 ratio"? I've got
that (on my 200 meter driveway in 2 spots).

make sure it can't roll away and repeat the bleed
procedure. It's always worked so far. If that doesn't work, all I can
suggest is join your heater hoses together, flush the heater core and see
if it's blocked. (Oh joy!) Cheers

I noticed a tee-fitting right on one of those hoses for flushing, so maybe
that's not a bad idea if this doesn't work. Can I borrow your road?

Dave

On Tue, 14 Dec 2004 12:46:13 +0000, Grunff <grunff (AT) ixxa (DOT) com> wrote:

Dave Hinz wrote:

I used Grunff's suggestion of opening the bleeder nipple on the thermostat
housing, but I'm failing to see how that, being lower than the heater core,
is going to help. What am I doing wrong?

I've usually managed to clear it by opening the thermostat bleed nipple
and revving the engine - it's the revving that does it.

Ah. Didn't rev, because I was in the garage and didn't have a hose on
the end of the bleeder. Seems like we're back to the c900 clutch
bleeding conversation all over again.

There was one time when I just couldn't clear an airlock, so I
pre-filled the heater core by connecting one end to a garden hose and
flushing through at high flow. That worked.

I'll get heat. It had warm before I replaced the thermostat which was
stuck open, so I know the heater core is good. Now, it has warm-ish,
and I *know* a c900 heater can pump out real heat. We'll get there.

Thanks again
Dave

Dave Hinz wrote:

What is a 1-in-3 road? I've never heard that term before, but I do have
30 acres of land with hills. Is this a "slope of 3:1 ratio"? I've got
that (on my 200 meter driveway in 2 spots).

Yes - sorry, it's my English heritage...

I noticed a tee-fitting right on one of those hoses for flushing, so
maybe
that's not a bad idea if this doesn't work. Can I borrow your road?

Any time you're in Australia, you're welcome! Cheers

On Tue, 14 Dec 2004 16:14:51 -0500, hippo <johnh (AT) nospam (DOT) shoal.net.au> wrote:

Dave Hinz wrote:

What is a 1-in-3 road? I've never heard that term before, but I do have
30 acres of land with hills. Is this a "slope of 3:1 ratio"? I've got
that (on my 200 meter driveway in 2 spots).

Yes - sorry, it's my English heritage...

Don't apologize for my ignorance of your language, please.

I noticed a tee-fitting right on one of those hoses for flushing, so
maybe
that's not a bad idea if this doesn't work. Can I borrow your road?

Any time you're in Australia, you're welcome! Cheers

Same for you, and Wisconsin.

Dave