Volvo 850 heater core replacement 2

[jpgurley]

OK the job is done!
I would request that the following information be added to the job description for the 850 heater core.
Mine is a 98 V70XC and to do it I decided I needed more room.
To remove the gas pedal assembly, slide the pivot pin slightly to the left and the pedal will come off.
Then take out the two bolts holding the pivot assembly in place thereby giving more room.
I found it best to install the pipes into place first into the junction box, then with the heater core in place but loose, slide the connections into the core. To make getting the screw in the bottom (the horizontal one) I used a bread tie to hold the bolt and it was much easier to install.
With the box loose and the two pipes you can push them into their holes and tighten everything up.
Now I just need to do a leak test and put the panels back.
And one more thing both side panels must come out which means taking the glove box out on this model.
Glad it is done! Now I have another car, an 850T5 to do the same job on.
thanks,
Jon

[taxidad]

Good on you Jon, it's a tight job. Precopster is an Aussie (so am I) so, although the heater core pipe-work is the same as yours, being RHD the gas pedal is on the far right of the vehicle for us so it's an obstacle we are fortunate not to have to deal with. Most of the work tight work is on the passenger's side for us, but we still have to remove the glove box. I wish I'd thought of your trick with the bread tie. I can see how it would have been much easier to install the pipes into the junction box first. I certainly fought with mine. Good addition to a common job!

[cn90]

I want to add to this excellent thread for those who want to bypass the Firewall Coupler. READ the DIY below:

http://volvoforums.com/forum/volvo-850- ... nes-46740/

1. Use Heater Hose with I.D.= 1/2" (or 5/8"). See thread above.

2. Using a tube cutter, cut the metal lines feeding the heater core to allow the heater hose to clamp on.

3. Feed the heater hose through the Coupler. But first, you may have to prepare (drill) the Coupler so it allows the heater hose to pass through.

4. The heater hose should be long enough to pass through the Firewall Coupler itself and reaches the engine block.
Pay attention to which hose goes to which port on engine block!
The thread talked about 1/2" vs 5/8" heater hose.
It is a bit hard to get the 1/2" hose onto the engine block side, but doable. You may want to stretch (expand) the hose a bit before attaching it to the engine block.

5. Then seal the Firewall Coupler with:

a. either "Butyl Rope" (couple bucks at autoglass repair shop). This stuff is sticky and seals door/window/glass very well.....
b. Or "GB Gardner Bender Electrical Duct Sealant" ($2 at Home Depot). This is the stuff electrician/AC techs use to seal AC lineset where it enters the house. It is similar to chewing gum in consistency.

[cn90]

I am thinking another option: modifying the coupler with brass fittings!

Get 2 brass "barb fittings" ($2 at hardware store): 5/8" on one end and 1/2" other end (or could be 1/2" on both ends)
Remove the coupler and drill appropriate hole sizes for the "barb fittings".
Slide the brass "barb fitting" x2 through the coupler and seal it with caulking or silicone caulk or whatever.

- Re-install the mod coupler back on the firewall.
- Inside cabin: a short hose from this new coupler to the cut pipes (cut the pipe with tube cutter as mentioned)
- Engine compartment: use standard 5/8" (or 1/2") heater hoses.

This allows you to replace appropriate hoses later w/o messing with the coupler any more.

SEE Pic. What do you think?


PS: This Barb Fitting $7.00 for a 5-pack at Home Depot, talking about cheap!

http://www.homedepot.com/h_d1/N-5yc1v/R ... =202904748

barbfitting.JPG (11.63 KiB) Viewed 3794 times

[cn90]

If you have ever done home plumbing before (i.e. knowing how to solder copper pipe using propane torch which is actually very easy), then you can do the following.

I was at Home Depot hardware store and verified the following:
- The 3/8” copper pipe has ID = 3/8” but the OD = 1/2" so it is a perfect fit for the cabin side.
- The 1/2” copper pipe has ID = 1/2” but the OD = 5/8" so it is a perfect fit for the engine side.

From INSIDE ------> ENGINE area:

3/8” copper pipe (maybe 4-5 inches long) ---> 45 deg 3/8” “street elbow” to turn 45 degrees ---> short section of 3/8” pipe ---> 3/8”-to-1/2” reducer ---> 1/2 “ pipe (this is where the 5/8” hose goes into).

(All of these plumbing stuff cost less than $20).

Once this is done, it is perfect: inside is 1/2" and engine area is 5/8”. I did verify this using the rubber hose with ID of 1/2" and ID of 5/8”.

I have not done this yet but just want to throw this out as an option.

[erikv11]

The pipes are 5/8 OD (0.625") on both sides of the coupler.

I did not know about that writeup when I eliminated the coupler junction on my car, but it was pretty easy. I used Gates Green Stripe 5/8 heater hose (1 inch OD, 0.6 inch ID). Fits right through the coupler once you remove the interior bits (no drilling etc needed).

It is not a cakewalk to maneuver the thick heater hose in the cabin, I think using a brass coupler might be more of a pain than it is worth. Later on you can just disconnect the stubby pipes at the heater core when needed.

[trillogy]

Great Post. Unfortunately, I couldn't use it because to day was the day I replaced the heater core. I had saved this section to a temporary folder and had intended to follow it. But, when I attempted to access MVS just before starting the job, the site was not working. So, blindly we (a mechanic friend and I) set about replacing the core.

It went fairly well, until trying to remove the couplings which go through the firewall on my 1993 Volvo 850 (non-turbo). They are almost "L" shaped and broke immediately. It was 3:30pm on a Saturday and the nearest Volvo dealer is 30 minutes away. So, they were not an option. What we ended up doing was using 5/8 heater hose through the fire wall and clamping both ends with screw type hose clamps. Much cheaper than the couplings and works fine. Everything is working great now.

[gshadow325]

Great Post. Unfortunately, I couldn't use it because to day was the day I replaced the heater core. I had saved this section to a temporary folder and had intended to follow it. But, when I attempted to access MVS just before starting the job, the site was not working. So, blindly we (a mechanic friend and I) set about replacing the core.

It went fairly well, until trying to remove the couplings which go through the firewall on my 1993 Volvo 850 (non-turbo). They are almost "L" shaped and broke immediately. It was 3:30pm on a Saturday and the nearest Volvo dealer is 30 minutes away. So, they were not an option. What we ended up doing was using 5/8 heater hose through the fire wall and clamping both ends with screw type hose clamps. Much cheaper than the couplings and works fine. Everything is working great now.

you not worried about outside water coming in? yeah MVS was down yesterday but other sites like volvospeed.com has a decent heater core write up too. try volvospeed next time, there are a load of 850 and early x70 stuff there!

[trillogy]

gshadow325, thanks for the info on volvospeed.com. I'll check it out.

As for outside water, I assume you mean entering through the firewall connector. As a temporary measure, I used some rubber tubing stuffed around the hoses. I will purchase "GB Gardner Bender Electrical Duct Sealant" as recommended from an above post to properly seal it.

By the way, 5/8 hose works fine for both side, in the engine compartment and the cabin. Simply push it over the metal stop on the tubing and clamp it there. No leaks.

[sockeye119]

I almost want to do this for fun. I replaced the heater core on my wifes 740 last year. It took all 12 hours. Eight to disassemble the underdash and just about everything else in the front of the car. Four to put it back. Then the plastic capped core only lasted 6 months before it blew up.