how to by pass heater matrix

deezilbob · Unread post by **deezilbob** » 22 Aug 2009, 15:19

hi all my heater matrix is leaking on my xantia td 1998,
how do i go about by-passing it as i dont fancy changing it?
it must have leaked onto my fan unit as thats not working either

citrov6 · Unread post by **citrov6** » 22 Aug 2009, 15:25

are you sure you want to bypass it coming to winter?

you do need to take out the dash to replace it, took me a weekend

andmcit · Unread post by **andmcit** » 22 Aug 2009, 15:29

You get a bridge between the input/output pipes on the bulkhread by cutting
two unique very expensive moulded pipes. This would only make sense if you
can get temporary pipes off a car in the breakers to chop up but then that
potentially stops someone using them to reapir their car...

It really isn't worth bypassing the matrix unless you're driving the car in VERY
hot sunny climes. I have a failed blower on one of my Xantia and it get's very
unpleasant driving a refrigerator with wheels with the pathetic dribble of heat
that is permeated through. I'd say bite the bullet and fix it!!

<edit>
Citroen uses an odd allegedly quick release bulkhead fitting on the
input/output pipes; these are made by the two pipes meeting parallel
into two male plugs that are held together on a bracket with a Z spring
that clips the fitment on a receiving female bracket. It would be serious
burning of bridges were you to cut up the plastic bracket on the bukhead
so a workable bypass would involve a siamesed parallel doctored pipe
from the feeds off the engine leaving the original in place undamaged!!

I'll see if I can find some pictures I have of all this; they're a real pig to
get at on the bulkhead behind the rocker and induction piping and worse
still if you have aircon pipes running in the way. Fixing the matrix would
be cleaner and arguably easier!!!

Andrew

Clogzz · Unread post by **Clogzz** » 22 Aug 2009, 15:52

Here’s my bypass, only good for hot places.
Without matrix, there’s no heat coming in at all … not from the firewall, not from the exhaust … nothing.

deezilbob · Unread post by **deezilbob** » 22 Aug 2009, 15:53

thanks andrew i would fix it , the only thing that troubles me is do i have to remove steering wheel? its airbag one..

deezilbob · Unread post by **deezilbob** » 22 Aug 2009, 16:08

ok my fan has started working again a bit..cant find where its leaking from? only the well thats wet under mat on passenger side but the carpets dry around the sides and top carpet is dry under dash?
could i try forte stop leak?

andmcit · Unread post by **andmcit** » 22 Aug 2009, 16:23

Forte may do it; what have you got to lose! £8?

The above shows the pipes arrangement of one of the Xantia range
(1.8i petrol) but there are a myriad variety of options with the diesel
having a T-joint IIRC halfway along the main run of one of the two pipes.

On the right you can see the 90? bend where the pipes meet the bulkhead;
they actually run into the bulkhead parallel to the floor and bend out and
downwards towards the ground behind the back of the engine.

Andrew

citrov6 · Unread post by **citrov6** » 22 Aug 2009, 17:43

deezilbob wrote:thanks andrew i would fix it , the only thing that troubles me is do i have to remove steering wheel? its airbag one..

no you don't have to remove the steering wheel, the column unbolts and you can drop it, get round.

undo and pullout the gearbox and handbrake trim shifting it toward the back of the car, then withdraw the dash over the steering wheel, it can stay in the car while you work between it and the bits behind.

once your in you the matrix pops out, you will be able to see if there is water in there. while i was there i cleaned it with detol and it was much more pleasant when i put it together.

the dash is bolted in quite thoroughly. there are 4 bolts in the engine compartment under the scuttle panel where the windscreen wipers are, you don't have to remove that mechanism.

if you have a copy of haynes it goes through the proceedure, but essentially nothing scarey has to be removed, everything can be done with screw drivers and spanners

deezilbob · Unread post by **deezilbob** » 22 Aug 2009, 17:53

good , thank you very much..ill try forte tomorrow for a temporary fix then ill order a matrix..

Unread post by **citroenxm** » 22 Aug 2009, 22:05

If its got original Citroen Mastic holding the trim onto the screen it WILL be a SOD to get off WITH OUT BREAKING YOUR SCREEN!!! Trust me, Ive done many and without softening the mastic first while cutting it , it will lift the top of the laminate or crack the screen...

I found useing a hair dryer on LOW HEAT and SLOWLY cutting the mastic worked.. TAKE YOUR TIME though....

Whats wrong with removing Air Bags?? Just take the battery off which you have to do anyway, and wait about 5 mins then you can get the bag off...

The scuttle HAS to come off to get at the 3 bolts securing the dash to the bulk head...

Paul

Unread post by **CitroJim** » 23 Aug 2009, 09:13

My heater matrix failed in my V6 before my ownership and the matrix was bypassed by cutting those expensive hoses and joining them with a length of 22mm copper water pipe

I've got a couple of sets of non-V6 hoses and will cut and join them into the V6 hoses.

It's still like it. A matrix change awaits. It's a pain but very soon now, some cabin heat is going to be needed, especially in the mornings...

When you do the matrix change, if not already said, be super careful with the matrix joint elbow. It's delicate and easily broken. Release it with the coolant hot and under pressure; the ehat and pressure helps the joint to release.

citrov6 · Unread post by **citrov6** » 23 Aug 2009, 12:17

i know too well how fragile the elbows are, especially with the v6 pressing up close to it, if your engine is very much in the way maybe drop it on a jack to give your self more space.

this was the most difficult part of the job and did infact break the elbow on mine. i replaced it with some silicon turbo hose i had lying around which has done a good job for the last year and a half and 15000miles

on mine the scuttle was pealing of the windscreen, so i suspect it had been done before and put back on with some weaker tacked foam. i alraldited it back on i think after

Xantidote · Unread post by **Xantidote** » 23 Aug 2009, 12:27

Replaced my matrix a few years ago, following the procedure as in Haynes. One or two things seemed not to need removal, but overall, it went OK.

If doing it again, I'd use digital camera to record location/route of wiring & connectors behind speedo/rev counter panel.

Paul is right about difficulty & care needed to remove scuttle from the the screen. I used an ordinary knife, and a sharpish wallpaper stripping knife, working from each side of screen to slowly break the bond - the knife would have been more effective had it been sharper. Never thought to use any heat.

Found a deep 10mm socket (I used 1/4" drive) useful to get at the 4 bolts in the engine compartment.

Whilst the panel's out, you've got access to check all the small illumination and warning lamp bulbs. Worth replacing any that are going black, or which have already failed and you've not been bothered to replace!

Martin

deezilbob · Unread post by **deezilbob** » 23 Aug 2009, 16:02

thanks everybody, much appreciated advice..
ive used the forte stop leak today as a temporary measure untill my new matrix arrives,hopefully get it done in the next week or two,
ive also put a dry newspaper in the upper half of the passengerside footwell to keep an eye on any drips.. none so far!!

Unread post by **CitroJim** » 23 Aug 2009, 21:40

Forte Stop leak is good stuff

It staved off my failing matrix in my 2.1TD for months before we replaced it.

I'd not recommend anything else though. My V6 had a leaky matrix and it looks like all sorts of concoctions were tried, including one that looked like clay!

I have a suspicion it contributed to the death of the gearbox as it blocked the transmission cooler.

To this day, despite a new rad and very thorough flushing I can still see traces of K-Seal in the system