View Full Version : Heater Matrix Replacement For S70`s

Wednesday 29th June 2005, 11:38

Hi chaps,

Just done my heater matrix myself cost £122.00 for the matrix and 2 new "o" rings for the rear heater pipes from nordic car parts
You need to be a VOC member to benifit from the discount 40% i`m told
I only found out it had gone whilst browsing this very forum and reading about steam from vents and wet footwells(i`ve got volvo rubber mats in all footwells so was unaware of a leak) and i put the steam down to a clogged and wet pollen filter doh !!! :slap:

If you do it yourself it takes about 2 hours so save yourself some cash and get your hands dirty

Description of what to do and tools required below (Car is a 1997 "P" S70 T5)

2 x Pipe clamps for 1 inch dia pipes

Torx Bits No`s 15 , 20 , 25 and either a ratchet or screwdriver for these

Plenty of high absorbancy rags/cloths and i mean plenty as you need enough to soak up at least 1 litre of coolant

Volvo type c coolant 1 litre or possibly 2 litres

If you have all of the above then we`ll start

1:Make sure the car is parked on level ground and has not been used for at least 2 hours i:e its cold or luke warm at the most and pop the bonnet

2:Remove cap from coolant expansion tank to release pressure from the system

3:Still in the engine compartment locate the 2 heater pipe hoses on the bulkhead/firewall they are to the right of the turbo unit Looking from the grill into the engine compartment and have YELLOW clips on them at the bulkhead ,Clamp the 2 pipes using the pipe clamps , space is tight so you may have to move the pipes upwards slightly in order to gain some clamping space

4:Right now its into the car
Move the steering wheel using the adjustment lever so that its in its uppermost position and lock it there.

Pull back both drivers and passengers front seats until they won`t move any further back

Remove the plastic trim from the base of the door area by pushing gently so the trim moves inwards towards the seat and the clips will release (it`s long and fragile so take care not to break it if need be you can pull up the rubber strip that runs along the door areas edge to make it easier)
This Helps for when you pull the carpets back

5:Working on the drivers side using the correct torx bit undo the one screw (under steering wheel)that holds the lower facia panel to the dash and pull towards you to remove (Note there is a slide glide in clip on the side of the heater matrix enclosure that holds the rear of the panel up)The heater vent for the footwell area will also come away with the panel as its stuck in position on the rear of the panel

If your car has the clutch pedal foot rest on the floor then push the plastic piece upwards or could be downwards depending on which way it was first fitted (Trial and error time) and it will release from its clips (note which way round it goes)

Next remove the plastic seat rail cover nearest the door opening (just pull it off)

Now pull the carpet from under the pedals (you may have to twist and fold the carpet in order to do this) and continue to pull it back and upwards taking care to remove it from the centre console overhang pull it up and then place it on top of the drivers seat (the carpet will not come out completly as it goes under the seat a little and under the seat rail mountings

Locate the carpet protector panel (Black plastic cover) and move it towards the centre console to disengage the 2 clips holding it in place (the second clip is hidden behind the centre console plastic panel) and remove

You should now be able to see the right hand side of the heater matrix enclosure(Any leaks should be clearly evident)

Now comes a major decision lift up the grey soundproofing matting that is on the floor the corner nearest the seat and door is easiest and look underneath
The matt is rubber faced with a sponge/foam backing about 1 inch thick
If your matrix has been leaking for sometime this matt will be saturated and may be discoloured (green coolant)

"I took the opportunity here to cut out the matt using a very sharp stanley knife"

5A:Looking into the footwell cut the matt about 2 inches above the bend in the matt as it rises towards the bulkhead and follow it around and along the transmission tunnel area (You may have to bend the floor air ducting a little in order to cut behind it).Once you have cut it all around lift it up at the corner again and pull it up and out wards to remove(This procedure also applies to the passenger side footwell)
Place the wet matt rubber side down on a sloping surface to allow any coolant to run off or use absorbant rags on the matt and walk on them to absorb any coolant soaked into the sponge
Use absorbant rags to mop up any coolant that remains in the footwell area

6:Moving over to the passenger side
Remove the side trim as previously described for the drivers side


Open the glove box and remove the torx screws holding the glove box insert to the facia 1 in each corner at the top and 4 along the bottom (six screws) and pull out the glovebox insert

Remove the 2 torx screws holding the lower facia panel to the upper dash area(i:e the 2 screws you just uncovered when you pulled out the glovebox insert) and pull the lower panel towards you to remove.

The footwell heater vent will not come away with the panel on this side
Note there is also a plastic slide guide clip on the heater matrix enclosure to hold the rear of the panel up

Again remove the plastic seat rail cover nearest the door opening (just pull it off)
And then reach up to get the rear of the carpet out of the footwell area and pull it down and towards the passenger seat pulling it out from under the centre console plastic overhang and again fold it up over the passenger seat

Locate the carpet protector panel (Black plastic cover) and remove by pulling towards the centre console to disengage the 2 clips as per the drivers side

The left hand side of the heater matrix should now be clearly visable (as should any leaks)



Place plenty of absorbant rags in both driver and passenger footwells including upto the bottom of the heater matrix enclosure but don`t obscure the housing or any fittings

Now working in the drivers footwell undo the 2 torx screws on the side of the matrix enclosure one is on the join line of the housing(horizontal) the other is behind the slide glide clip(large white plastic thing) and is vertical in its orientation
BE PREPARED FOR SOME COOLANT SPILLAGE (a pair of rubber gloves might come in handy here)

Now over to the passenger footwell and again remove the 2 torx screws one horizontal and one vertical as per the drivers side

Now locate the black plastic clamp that holds the two heater pipes at the rear of the matrix (you should be able too twist the housing slightly to gain access)

LOOK at the front of this clamp and you should see a torx screw holding the clamp to the matrix enclosure its between the two pipes at the bottom of enclosure not on the clamp itself remove the front screw and then twist or pull rearwards the two clamped metal feed pipes off the matrix housing and move slightly to onside removing the two old "O" rings as you do

Next pull the matrix housing down and forwards to remove
This is tight for space and may take a bit of jostling before it comes away
And there you have it one busted heater matrix in its housing

Not so hard was it

Now turn the housing upside down and remove the four torx screws holding the old matrix in place remove the matrix and the clean and dry the housing

Place the new matrix (DO NOT REMOVE THE FOAM STRIP FROM THE MATRIX) in the housing the correct way around i:e check the screw holes for alignment and secure using the four torx screws

Place the new "O" rings into the new matrix pipe feeds

Working in the passenger footwell offer the matrix and housing upto the top half of the unit tilting the new part towards the bulkhead as you do so you may have to wiggle it about abit but it should slide into the top of the housing quite easily when its in position secure with the four torx screws 2 either side in the positions that they were removed from

Push the metal feed pipes into the pipes on the matrix housing and secure using the torx screw from the housing to the black plastic clamp as per removal

Remove any absorbant rags from both footwells

All thats left now is to put back the bits we took out or moved

Ensure that the rubber under carpet matts(soundproofing) are completley dry before you put them back into the car

Just put everything back in the order you took it out


Just under the bonnet to go

10:Remove the 2 pipe clamps from the heater hoses
Top up the cooling system expansion tank as required and replace the screw on cap


Check the handbrake is applied and cars in neutral
Then start her up and allow car to reach operating temp checking coolant level
When car is at operating temp switch on heaters and blowers to check heat output if its very hot then excellent the job is done
However if its cold or luke warm first check radiator top hose if this is hot then you have an air lock in the cooling system
Switch of the engine
And then using another rag gently squeeze the top radiator hose in an attempt to draw the air out of the system (this is trial end error so may take a while)
Watch out for coolant over flowing from the expansion tank

I hope this covers it


1997 S70 T5
Now has new heater matrix , pollen filter , air filter , oil and filter

Saturday 12th August 2006, 15:29
Just done this job and it was made easy by this thread, well done mate and a huge thanks.... Every credit to you ;)

Saturday 12th August 2006, 16:38
Many thanks fraz

And thanks again to Fraz13 who took the attached pics of the heater matrix replacement job at various stages

Hope these help a few more people get an idea of what to do