In the thread below, songzunhuang discussed replacing the two (2) heater hoses etc., only to realize that it is much better to get rid of the whole thing (O-rings, firewall coupler etc. etc.) and simplified the system by using this approach: Heater Core ---> Cut Pipes ---> Generic Heater Hoses ---> Gutted Coupler ---> Re-used the barb fittings ---> Generic Heater Hoses ---> Engine:
https://www.matthewsvolvosite.com/forums ... hp?t=67217
Make sure you read through the entire thread above.
Another good thread by rspi:
https://www.matthewsvolvosite.com/forums ... hp?t=58733
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-Anyway, this is my experience with ebay Heater Core ($40 incl. shipping), and used standard heater hoses to simplify this whole convoluted Volvo setup.
-This is strictly preventive maintenance at 167K. The cabin once in while has this very faint sweet smell. The car consumes two (2) cups of coolant every 5K or so (going from Max to Min).
Since others have reported the heater hoses can burst, dumping coolant in a matter of seconds and since the heater hoses are 18 years/167K old, it is time to replace them on a preventive basis. This is one job you do NOT want to do in the middle of nowhere, trust me.
- Budget 4-6h for this whole project.
PARTS:
- Ebay Heater Core ($40) Do NOT use the two (2) O-rings that come with the ebay heater core: when cold they are OK but when you drive the car, the system is pressurized, they will seep a bit. Best is to buy two (2) Volvo OEM O-ring (PN 3545586), about $3-$4/each.
- Others mentioned the ebay heater core can smell. So I boiled some water, added some DW detergent, then dipped the HC in there to clean all the grease (I removed the foam for this process, maybe unnecessary step), then rinse with water. You can put the HC in the DW but it takes a long time for the whole 2-3h cycle.
- Standard 5/8-inch heater hose. I used Gates brand (someone told me Gates is better than Thermoid brand), 6 feet is bare bone minimum. I bought 8 feet just in case, it is about $1.50-$2.00/ft at Napa auto parts. In contrast, if you buy Volvo OEM heater hoses, they are about $60/each!
- Six (6) clamps for the project: 2 inside the cabin, and 4 at the firewall area.
- Prestone coolant and distilled water.
TOOLS:
- Torx keys
- Screwdrivers
- Pair of pliers
- Angle Grinder or Dremel tool to remove factory crimp in order to re-use the barb fittings.
Wear goggles when operating Angle Grinder or Dremel tool!!!
- Butyl Rope (stuff used seal vapor berrier or older windshield glass, buy it at local auto glass store), this stuff is used to seal the firewall coupler/generic heater hose space. Or you can use your favorite caulking stuff, as long as it can handle engine heat.
- Latex gloves: there are a lot of sharp edges to deal with!
- Volvo-S70-HC-01.JPG (108.97 KiB) Viewed 8312 times
PROCEDURE:
1. D/C battery cables and remove battery from car. Make sure you have code for the radio.
2. Drain coolant: I drained it from LOWER rad hose (avoid using the radiator petcock!). If coolant is new, then drain it into a clean container to re-use it. You may need a funnel/coffe filter paper to filter out debris before putting it back into the reservoir.
3. D/C MAF connector and air intake tubing etc. Then d/c the LOWER rad hose from the engine. You will see that the two (2) heater hoses connect as follows:
- The UPPER heater hose to the Front part.
- The LOWER heater hose connects to the area under the bigger pipe (that connects to the LOWER rad hose). When in doubt, feel around using your hands.
4. Note that the heater hoses use an unusual type of clamps: 7-mm socket or wrench is the key!
5. In order to minimize spill inside cabin:
- I used a funnel to the UPPER heater hose, added some water so it runs clean.
- Then used a separate tubing, attach it to the UP PER heater hose, then blew through it until no more water comes out.
- Once I d/c the heater core pipes, very little clean water came out.
6. To d/c the heater hoses from the firewall coupler, squeeze the yellow clips then ROTATE the pipes, then pull it out. The coupler is held by two (2) Torx 15 screws.
7. Old heater hoses not too bad at 167K, but they are on borrowed time:
8. Once you cut and remove the crimp, one side (with the edge) goes to the engine and the other goes to cabin. However, if you reverse it, it is fine too. Inside the cabin, cut the pipes as shown below, then make sure you have heater hose long enough to:
a. Cover the pipes by about 2-3 inches to avoid leak.
b. Stick out of the firewall by about 1.5 inches.
9. Old heater core with 167K: not too bad, but you can see where the coolant leaked out and dry residue left behind.
10. Inside the cabin:
a. Remove the gas pedal (slide the pivot pin to the LEFT), then undo the 10-mm bolts to remove the gas pedal base.
b. Undo the Torx 25 bolt that holds the pipes to the heater core, then d/c the pipes. Photo shows pipes cut ready for re-assembly.
11. The heater core DIY is covered in the video by rspi above. On each side, you need to remove the 2 screws as shown (T15 and T25).
12. Next photo shows you the gutted coupler: no need for any special tool, use a pair of cutting pliers and remove the inner core, very easy, it slides right out. The holes left behind are just a tiny bit bigger than the O.D. of the 5/8-inch heater hose. Then cover the gap with caulking stuff. I used Butyl Rope. BEST is to install the gutted coupler first, then slide the heater hoses through. Connect all the clamps etc. Once everything is good, then apply Butyl Rope to both inside and outside areas to prevent fume from entering the cabin.
13. Final photo before filling up with coolant. Note that the AC drain must be re-connected to the floor drain.
14. Fill system with the correct amount of coolant. Since I flushed the system with distilled water to get rid of old coolant, and since coolant capacity is 7L for turbo (~7.2L for non-turbo), I added 3.5L of pure Prestone coolant to ensure I have the 50-50 mix for my winter months. Once I added 3.5L of pure Prestone, I only used distilled water afterwards.
- Drive the car around the blocks, don’t go too far (if you do, carry extra distilled water in the trunk!), chances are you will need to top up with more water (or coolant) twice. Make sure th engine is cooled down before opening the cap.
This is your chance to get rid of the convoluted Volvo design with a gazillion of O-rings, yellow clips, this clip that clip, this O-ring that O-ring etc. It is a bullet-proof system when you do it this way! Use only quality heater hose (Gates) or silicone hoses.
That is all boys and girl…
PS: The ebay heater core is as hot as the Volvo OEM heater core.
