Volvo 850 heater core replacement 2

Post by **rspi** » 07 Dec 2011, 09:32

I helped a guy do a heater core replacement and I did not see a need to disconnect the tubes that connect to the firewall coupling. There is a screw at the bottom of the heater core, where the connections/lines go into the bottom of it. When that T25 screw is removed you can pull the bottom of the heater core away from the lines/connection and take the core out with no problem.

Unfortionately, the guy had buypassed the core/coupling months ago and when he tried to reconnect the lines to the coupling it snapped. We then use the heater hose, 5/8" I guess and connected them through the firewall as well because he did not want to pay our stealer $68 for a new coupling.

wbbaz · Post by **wbbaz** » 21 Jan 2012, 17:30

Hello, I'm new to your site. I have read all the comments on the R&R of the heater core and the step by step is great. I just replaced a heater core and hose coupler in my 96 850 and I cant get it to provide heat. Is there an air lock; did I cross the hoses when I re-attached them to the coupler; is it a bad core? I've topped off the anti-freeze several times to no avail; and there are no leaks, and the low fluid light no longer comes on. The blower works fine.

Thanks much

wbbaz

Post by **precopster** » 21 Jan 2012, 20:17

Hi welcome to the forum!!

Does your temp guage reach the 3 o' clock position? These aftermarket cores produce a lot less heat than the Behr (OEM) brand so don't expect a furnace quality heater.

How hot is the upper hose when it does reach the 3 o'clock position? Is it nice and hot? If not you may have a always open thermostat. As you have a NA or non-turbo you may need a new 92 degree thermostat.

I've had the cooling system drained on a 850 many times and never had a serious air lock, only had to do multiple top-up b/w warm-up/cool down cycles. 3 top ups at around 1/5 quart each time. Eventually the air in the system gets to the expansion tank while it's cooling.

kfk721 · Post by **kfk721** » 29 Feb 2012, 17:51

Hi, I replaced the heater core in my '98 S70 over a year ago and have had no leaks or problems until this afternoon. About 3 miles into my drive home from work, something under the dash exploded. It sounded as if a gasket gave out and the car's cabin suddenly filled with a thick steam. After dropping to windows to clear the cabin, I was able to drive 2 miles home.
I'm a rookie at this and not sure where to look. Is there a weak link that is most likely to have blown? Is there an easy way to shut down the system so that I can continue driving short commutes until I can get this fixed? I can do without the heat for a while if necessary. I'd appreciate any suggestions or advise. Thanks!

Post by **Ozark Lee** » 29 Feb 2012, 22:21

Welcome to MVS,

You can bypass the heater core - I have seen two methods to do it.

In my mind the safest method is to remove both lines to the heater core from the block and insert a heather hose between the two nipples from the block.

The other method that some have used is to get a short piece of heater hose, remove both of the quick connect lines at the firewall, and insert the hose between the nipples on the heater hose lines themselves. On that method there is not a lot of clamping surface to work with and I would be fearful of one of the hoses popping off.

The first method requires crawling under the car to get to the hoses at the block while the second method can be accomplished from above.

...Lee

PEWPEW · Post by **PEWPEW** » 26 Jun 2012, 19:06

Hi all,

Got my replacement heater core yesterday. The firewall coupling was totally broken but I couldnt afford to replace it.
I wound up using heater hose clamped from the block through the firewall coupling to the piping on the core. Seems to work quite well. Should do till I get the new coupling.
Problem is that I didn't tighten the clamps enough on the core piping so it has a very small leak. I was going to fix it last night but I ran out of coolant.

Post by **MoVolvos** » 26 Jun 2012, 22:26

-
Straight Heater Hose No Block
http://volvoforums.com/forum/volvo-850- ... nes-46740/

Blessings,
BKM
-

PEWPEW · Post by **PEWPEW** » 18 Jul 2012, 01:12

BKM98 S70 T5 wrote:-
Straight Heater Hose No Block
http://volvoforums.com/forum/volvo-850- ... nes-46740/

Blessings,
BKM
-

Worked a treat cutting the metal pipes shorter and NO LEAKS! Finally have some warmth! So efficent I have to back the heat off once the engine reaches operating temp.

valvster · Post by **valvster** » 18 Jul 2012, 01:30

Good to hear all went OK PEWPEW....I just walked in from checking my heater core and coincidently this post popped up in my email. My heater core is still original on my '96 850, has no leaks and looks OK (so is the radiator) but kinda think it may be prudent to replace before summer.
I like the idea of straight heater hose but notice the hose to the block has a tight moulded bend in it...did you have any trouble with kinking?
Valvster

PEWPEW · Post by **PEWPEW** » 19 Jul 2012, 20:20

valvster wrote:Good to hear all went OK PEWPEW....I just walked in from checking my heater core and coincidently this post popped up in my email. My heater core is still original on my '96 850, has no leaks and looks OK (so is the radiator) but kinda think it may be prudent to replace before summer.
I like the idea of straight heater hose but notice the hose to the block has a tight moulded bend in it...did you have any trouble with kinking?
Valvster

Hey Valvster,
I did make the hose a little longer. The bends are not excessive, so no kinking. I'll try to get a photo of the engine bay over the weekend for you as I just got my lowering springs and spring seats.
The main thing I must remedy is the fire wall holes, some sort of filler around the hoses to stop engine noise coming through. It isn't too bad though.

Volvo 850 heater core replacement 2

Re: Volvo 850 heater core replacement 2