15 replies to this topic

[f1fanoly]

I've got a '97 850GLT wagon and am getting coolant smell from the heater,so i'm assuming I need to replace the heater core and o rings.I've read through the repair threads and was wondering what I need to do regarding the cooling system when I pull the heater core.Do I drain it to prevent excessive coolant loss into the cabin?Maybe i'm overlooking it but I dont recall this being mentioned.I know its recommended to use plastic bag to catch coolant from the core,but what about the lines?What about removing the lines that go into the firewall and purging the core with air prior to disassembly?Or is there not enough coolant loss to worry about it?I just completed motor swap (replaced LPT with '98T5)and have new,Honda brand coolant and would rather not have to buy more if I didnt have to.Advice on this matter is appreciated,thanks.

[matt b]

You drain at the back of the block or better, the bottom of your radiator.

Honda coolant ? Have you thought about Volvo coolant next time ? It's not too pricey.

Ad yes, you'll lose coolant in the cabin, just use bags to catch the excess and plan on having a bunch of old towels available. It's messy, even when you drain coolant.

[jdlc]

I've got a '97 850GLT wagon and am getting coolant smell from the heater,so i'm assuming I need to replace the heater core and o rings.I've read through the repair threads and was wondering what I need to do regarding the cooling system when I pull the heater core.Do I drain it to prevent excessive coolant loss into the cabin?Maybe i'm overlooking it but I dont recall this being mentioned.I know its recommended to use plastic bag to catch coolant from the core,but what about the lines?What about removing the lines that go into the firewall and purging the core with air prior to disassembly?Or is there not enough coolant loss to worry about it?I just completed motor swap (replaced LPT with '98T5)and have new,Honda brand coolant and would rather not have to buy more if I didnt have to.Advice on this matter is appreciated,thanks.

Normally, yes, using drain plug on the bottom of the rad, driver-side (ds).

I find it too much hassle though, and figured that I had to raise the car somehow anyway to drain and capture clean coolant, so last I did it
(which the yesterday for the 98 GLT) I raised the driver side using supplied jack, and use a hose to siphon out coolant from the expansion tank into a clean container and shoved the hose as deep as I could, all the way to the bottom of the bottom hole. The idea is to make the coolant level approx at same level as the htr hoses on the rear of the engine (ds). I got about half a gallon. Then using a big and clean plastic bag, I captured all the coolant when I separated the htr core from the tube coming down from the firewall. I captured another half a gallon (I used a big black bag - contractor grade lawn bags with no holes so I captured all coolants that flowed and hardly lost a drop - but nevertheless prepared old towels and placed them on the floor after partially pulling up the carpet ). The bag was clean, so coolant was reusable.

I don't know which write-up you read, but worth mentioning below:
The tubes can be pushed down gently out of the way without breaking anything, so I didn't need to replace the firewall connector, but I did use two new black Volvo o-rings to install the htr core. The green ones both FCP and eEuroparts sell, (that they say Volvo eom) are no good.
Also I pulled out the htr core from the passenger side as the driver side has the pedals on the way, as well as the pair of tube.
GL.

[Part Time]

Hi,
You will get better advice from someone else, no doubt. But I can tell you my recent experience.
I have a '96 850 GLT sedan - I did not drain any coolant before removing the core. The min. I popped the seal between the core and the pipes, I got an easy gallon unloaded in my foot well. The plastic (yard sized) trash bag I spread out was not big enough to contain it without me pulling up the edges then damming it up underneath with rags which were luckily nearby.
I ended up bailing it out, but it was a near disaster.

Lessons learned from personal experience are great, but it's always easier to learn from the wisdom of others who have gone before. I love this forum.

[jdlc]

Hi,
You will get better advice from someone else, no doubt. But I can tell you my recent experience.
I have a '96 850 GLT sedan - I did not drain any coolant before removing the core. The min. I popped the seal between the core and the pipes, I got an easy gallon unloaded in my foot well. The plastic (yard sized) trash bag I spread out was not big enough to contain it without me pulling up the edges then damming it up underneath with rags which were luckily nearby.
I ended up bailing it out, but it was a near disaster.

Lessons learned from personal experience are great, but it's always easier to learn from the wisdom of others who have gone before. I love this forum.

I used 'the bag', that is the inside of the plastic bag to capture the coolant. By pulling the lip of the bag around the htr core drains, I caught the gushing coolant, and into the bag it went.

Done it 3x, once to each of my 98s and worked like a charm everytime

[Modus]

Indeed, the bag is the best approach.
There really isn't that much coolant to be drained out.
Like 1 quart at the most.

Get yourself a 45 gallon plastic garbage bag for enough room to maneuver the mouth of the bag around the work area.
When you pull the core, it will dribble out a little bit, from the firewall pipes, then when you pull the core for disassembly to the rear as seen in the pictures in the write up, then you'll be draining the core. There isn't much coolant that is stored in the core.

Here is a picture of that day, with the amount of coolant in the bag. It was 3 pints if that.

[f1fanoly]

Indeed, the bag is the best approach.
There really isn't that much coolant to be drained out.
Like 1 quart at the most.

Get yourself a 45 gallon plastic garbage bag for enough room to maneuver the mouth of the bag around the work area.
When you pull the core, it will dribble out a little bit, from the firewall pipes, then when you pull the core for disassembly to the rear as seen in the pictures in the write up, then you'll be draining the core. There isn't much coolant that is stored in the core.

Here is a picture of that day, with the amount of coolant in the bag. It was 3 pints if that.

Ok,I think i can handle that but I want to confirm that I need to drain the cooling system before proceeding with removing the core.

[bob850]

You don't absolutely have to drain the coolant before removing the core. But it is highly recommended, as much less coolant will come gushing out of the lines if you drain it first.

Coolant is cheap and it never hurts to freshen it up anyway.

[jdlc]

Ok,I think i can handle that but I want to confirm that I need to drain the cooling system before proceeding with removing the core.

In the picture above, there's little coolant because IT WAS drained although not mentioned explicitly - about a quart he said, that's the clue because post #4 says it all.

It's really up to you, but the thread will give you an idea what to expect when you do it either way. GL.

[JC 855 GLT-R]

ive done it plenty of times in my 96, my moms 99, and my cousins 98 all NA motors, the 98 was drained and the lines going through the firewall were also disconnected and i got about a cup of coolant this was also an opportunity to flush the system. my 96 and my moms 99 had a blown heater core which overheated the motor and already spewed into the cabin, the interior was already gutted in both cars when i did it and i still got about a quart of coolant come out.

[Modus]

In the picture above, there's little coolant because IT WAS drained although not mentioned explicitly - about a quart he said, that's the clue because post #4 says it all.

It's really up to you, but the thread will give you an idea what to expect when you do it either way. GL.

Umm where you there?

I'm telling you I didn't drain it from the engine bay. It was possibly low on coolant, I really don't remember it was such a longing time ago. Notice the dexcool sludge.

My second and 3rd time replacing the core I did the same thing. I never had to drain first. (seemed to much work to do so) ( I'm lazy)

Plastic bag capture fluid, and reuse for later. 3 pints, 1 quart, it's hard to measure in a plastic bag corner. Either way it really isn't that much.

[jdlc]

Umm where you there?

I'm telling you I didn't drain it from the engine bay. It was possibly low on coolant, I really don't remember it was such a longing time ago. Notice the dexcool sludge.

My second and 3rd time replacing the core I did the same thing. I never had to drain first. (seemed to much work to do so) ( I'm lazy)

Plastic bag capture fluid, and reuse for later. 3 pints, 1 quart, it's hard to measure in a plastic bag corner. Either way it really isn't that much.

I was not, but you didn't explicitly say so that you didn't.
Not sure what's going on with yours, however, your result is inconsistent with mine and the guy in post #4.
And I just did mine not a week ago. I'm thinking maybe you didn't remove the expansion tank cap, and vacuum prevented the coolant from coming out.

Err on the side of caution is all I can say: if you are to tell members asking advise that not even a quart will come out when you do not drain, and almost a gallon would, then they might be overwhelmed and not prepare and mess up.

[Ozark Lee]

In my case I just pulled the hoses from the firewall and let a bit hit the driveway before I tied them up with bailing wire to the master cylinder above the head. I lost maybe a pint and maybe the neighbor's irritating cat will come over and drink it - it (the cat) will be less irritating after that.

The trash bag is an absolute necessity but you can ShopVac out what is left in the core and cut down on fluid leakage.

I eff'd up and dropped my ratchet into the trash bag as I was removing it and screwed up big time and doused the carpet with antifreeze since the ratchet held one corner of the bag down.

...Lee

[bob850]

Err on the side of caution is all I can say: if you are to tell members asking advise that not even a quart will come out when you do not drain, and almost a gallon would, then they might be overwhelmed and not prepare and mess up.

Remember the reservoir cap issue. One time I did it, I had what I thought was all the fluid. Then later took the cap off to inspect it and more fluid came pouring out. Stupid mistake, but easy to overlook.

Take the cap off before you do anything so whatever is going to drain does in fact drain the first time.

[Bah]

Just drain your coolant anyways...it takes like 5 minutes to get it setup to do....
Chances are your coolant is nasty and old anyways...and 2 gallons of antifreeze from walmart is $7 each for 50/50.

[Modus]

I was not, but you didn't explicitly say so that you didn't.
Not sure what's going on with yours, however, your result is inconsistent with mine and the guy in post #4.
And I just did mine not a week ago. I'm thinking maybe you didn't remove the expansion tank cap, and vacuum prevented the coolant from coming out.

Err on the side of caution is all I can say: if you are to tell members asking advise that not even a quart will come out when you do not drain, and almost a gallon would, then they might be overwhelmed and not prepare and mess up.

Indeed! I was silly of me to say so, my apologies. Agreed, even though sometimes not that much coolant comes out prepare for a deluge if it maybe.