Heater matrix bypass

[kbf]

My M-reg 1.3 Maestro seems to have sprung a leak from its heater matrix (slow but steady trickle of antifreeze into passenger footwell). Tried tightening the allen bolts securing the input/output pipes to the matrix housing (just incase they had come loose & the gasket was leaking), but no improvement. Beyond that, as a typical gal, I don't have the technical know-how or tools to even contemplate removal of the dash & examination/replacement of the matrix. That leaves me pretty much at the mercy of local garages, all of whom (in standard anti-Maestro fashion) have told me that due to the car's age & mileage (14 years & 135,000 - still with its original petrol engine), its not worth the cost or effort. Needless to say, as the car itself is running fine & was (until this leak) in daily use, I don't want to consign it to the scrap heap for a simple coolant leak! So, as I don't particularly want to risk using leak sealants such as Radweld (heard too many horror stories), how best can I bypass the heater matrix system? I know I won't have any heating by doing this, but that's nothing compared to the prospect of having to give up my beloved Maestro! I believe its possible to effect a bypass using piping & jubilee clips. If so, what sort of piping do I need to use, how do I go about it & will this be a permanent solution? Any advice would be much appreciated!

[xamtex]

despite any horror stories you have heard i would go down the radweld route for this problem.....well....not radweld but a product called "BARS LEAKS".i have used various rad sealers over the years with few problems and this one in my opinion is the best(assuming its still available).
bypassing the matrix is ok?but what happens in the winter?

[G Force]

I believe its possible to effect a bypass using piping & jubilee clips. If so, what sort of piping do I need to use, how do I go about it & will this be a permanent solution? Any advice would be much appreciated!

If you really want to bypass the heater:eek: then remove the two heater hoses where they enter the bulkhead in the engine bay. You can then connect them together with something like a pre soldered 13mm copper pipe joint, you can get one at any plumbers merchant.

So that you don't loose much coolant clamp the hoses before you remove them.

I would not want to be without a heater on a permenent basis so I would keep asking around until you find someone who can repair the matrix at a reasonable price.:)

[E_T_V]

I think that the existing pipe that runs across to the heater matrix is long enough to loop back on itself to bypass the matrix as a temporary measure. There are no ill effects other than the obvious loss of hot air to the interior!

It is usually the pipes that lead to the matrix that leak rather than the matrix itself. Sometimes these can be repaired and sometimes not. It isn't a big job to remove the dash (5 bolts and 4 torx screws, some screws and some clips) so don't be put off by it. I'm not sure if the pipes can be removed with the dash in place though, if you do find it is these leaking.

[Russ]

Its not actually that bigger job to change the matrix if you drill out the glovebox plastic rivetts. I see what you say about not being mechanicaly minded but if you find a tame mechanic and explain it shoud reduce your bill somewhat. As ETV says its more often the pipes themselves that leak

Russ

[Diesel Dave]

This is topical. My own 1994 Maestro TD has a leak at the Matrix or somewhere close by.
I had got to the stage of adding one and a half litres of water to the expansion tank every day but really could have saved time by just pouring it into the passenger footwell.

I had previously tried Radweld but that didn't make a difference.

I have the steering wheel off and I thought all the dash screws out but the dash is still in there. I thought I may as well do a proper job as I have a spare matrix and pipes, and boosted by the confidence of changing the cam belt and injection pump, power steering belt and top engine mount in 'Diesel Phil's car (admittedly with help).

Diesel Dave

[MG MAL]

I have the steering wheel off and I thought all the dash screws out but the dash is still in there.

I take it that you did'nt remove the fixing behind the radio then?.

Remove the dash binnacle and surround Plus sterring wheel and loosen column top mounts.
Once the screws on the ends are out, and the one behind the radio, its a case of lift from the bottom and then pull forward from the top.





Mal.

[Simon]

More than likely it will be the O rings in the joint between the matrix and its mating flange that have perished, causing the leak. Part no BAU 5898 available from X Part outlets (google for details). Unfortunately, they are only available in multi packs of 5 and you only need 2.

[Diesel Dave]

I'll try and get to that on Monday night. Just preppng my Mini for MOT this week.

Diesel Dave

[talkingcars]

deleted by poster

[secubis3]

You will normally find that the two black pipes corrode and start to leak. You will need to inspect these by taking them off the matrix heater. You need to remove 2 rubber hoses from inside the engine compartment that run into and out of the bulkhead, if the coolant is dirty then chances are the pipe are corroded. Undo the allen screws/bolts from the matrix, you will need to lay on your back under the passengers seat to do this and pull it away from the assembly.
If the pipes are holed you can either replace them with ones from a scrappy or use a bit of copper piping braised over to make a sealed joint.

Flush the coolent and replace it with new, clean the matrix pipes with a thin brush that is use to clean out bottles.

Test then replace your pipes, adding a sealent for the facing surfaces.

I did this in about a day with the hardest bit being the contortionist impression to get the pipes off and on. Result - better hetaer and slighly lower running temp. Works a treat.

[kbf]

[QUOTE=secubis3]You will normally find that the two black pipes corrode and start to leak. You will need to inspect these by taking them off the matrix heater. You need to remove 2 rubber hoses from inside the engine compartment that run into and out of the bulkhead, if the coolant is dirty then chances are the pipe are corroded.

Thanks for the info, but I really don't think its a pipe issue as they not only look / feel sound on the outside, but the leaking coolant is squeaky clean / clear. It could be the O-rings (as suggested by Simon) or, most likely, a blocked / leaking matrix (as I haven't had much heat coming from the heater for yonks!). Moreover, the coolant appears to be leaking from the flange edge - the pipes are almost always completely dry. Anyways, in order to at least temporarily resolve the matter & allow me to drive the car without risk of losing coolant / overheating, I've taken G-Force's advice & duly effected a heater by-pass, which is working a treat! My Maestro's due its next MOT come mid-July, so I'll hang fire on pursuing the problem further until I know the outcome of that. Fingers crossed, "Beany" (my car) will do me proud & get through without anything major to address! In the meantime, many thanks to everyone for "chipping in" their suggestions - much appreciated all!

[Diesel Dave]

You will normally find that the two black pipes corrode and start to leak. You will need to inspect these by taking them off the matrix heater. You need to remove 2 rubber hoses from inside the engine compartment that run into and out of the bulkhead, if the coolant is dirty then chances are the pipe are corroded. Undo the allen screws/bolts from the matrix, you will need to lay on your back under the passengers seat to do this and pull it away from the assembly.
If the pipes are holed you can either replace them with ones from a scrappy or use a bit of copper piping braised over to make a sealed joint.

Flush the coolent and replace it with new, clean the matrix pipes with a thin brush that is use to clean out bottles.

Test then replace your pipes, adding a sealent for the facing surfaces.

I did this in about a day with the hardest bit being the contortionist impression to get the pipes off and on. Result - better hetaer and slighly lower running temp. Works a treat.
An update. This is exactly what has happened. The heater pipes connecting to the matrix have corroded, causing the leak. I have replaced the o-rings (71p each) and sealed the area with bathroom sealant and am now putting everything back.

I didn't take the dash out completely, just removed enough to be able to lift it to enable the heater pipes to be moved out of the way. Fingers-crossed.. that will be it.

Diesel Dave