Think I finally fixed my leaking heater pipes

[Luckyone]

Edit - note these pictures are from a 97 built 98 registered 4.5. Cerbs before that and a for a bit after will be the same, but by 99 it was a bit different. Updated pictures for a 99 (& probably all later cars) now added at the end of the thread.

Ever since I rebuilt the Cerb the heater pipes wouldn’t stop leaking where they join the heater in the passenger footwell. I took them off loads of times & cleaned them them till they were shiny, tried slip rings under the jubilee clamps but nothing worked. So in the end I pulled the heater out & took out the matrix to check it wasn’t something inside.







The matrix its self was fine, but I realised the copper pipes had got crushed out of shape. You can see from the cross section after I cut the flared ends off.



I thought I would be able to just solder on a regular plumbing fitting, but of course TVR managed to find some obscure pipes size that’s different to any metric or the old imperial fittings. So I managed flare out the old pipe by banging a suitably sized socket into it, it seems quite thin walled so wasn’t actually very difficult, then just some olives soldered on to strengthen it a bit and act as the flare.



I found a good use for the kids sledge



They make a nice large capacity low-profile container! Useful so you can drop the car down really low to help get as much coolant out as possible.

Edited by Luckyone on Sunday 29th September 14:08

[pmessling]

Ive been looking at the heating system today trying to find an electronic bypass valve that could be used to divert the coolant from the matrix for use in the summer, there are a few places that it could be fitted if I could find one.

[Luckyone]

pmessling said:

Ive been looking at the heating system today trying to find an electronic bypass valve that could be used to divert the coolant from the matrix for use in the summer, there are a few places that it could be fitted if I could find one.

Interesting, is that an attempt to keep the cabin a bit cooler? Yes there is plenty of space for something like that.

My better half had to take the Cerb on the three hour drive for the first day of her new jobs to get to their HQ. It was on one if the hottest days this summer, she was non too impressed I hadn’t got round to having the A/C regassed!

[pmessling]

Yeah the heat is always there so to be able to bypass it would stop the hot air at the windcreen which gets direct back at you.

[Luckyone]

pmessling said:

Yeah the heat is always there so to be able to bypass it would stop the hot air at the windcreen which gets direct back at you.

Ah, yes it probably would help a bit.

But has yours not got the flappy cut off valve (bit of aluminium on a hinge where the pipe that runs over the passenger footwell enters the air box) to stop the air from the hot side getting into the air box? They are all a bit different but on our 97 / 98 car the pressure of the air from the cold fan keeps that valve shut stopping any air from the heater getting into the system.

Of course the passenger wing will still get a bit warm from the matrix, but I’ve not noticed it compared to the heat from the tunnel! Even with a lot if extra heat shielding it still gets a bit warm.

I have posted before about the official TVR mod of blocking the fresh air coming down the passenger wing & cutting a hole to make the heater recirculation only. With out that mod the force of air pressure when traveling at speed will cause hot air from the matrix to leak past the valve.

That only applies to the earlier cars though, I think the later ones with the ball type windscreen demister had it done anyway. In addition though I think there are some middle year Cerbs with a different design again, it’s possible that could always leak hot air, maybe it was you who said yours different years ago!

[phillpot]

pmessling said:

Ive been trying to find an electronic bypass valve that could be used to divert the coolant from the matrix

Any good? ..... 12 volt 3 port valve


and three of these.

Edited by phillpot on Friday 10th August 22:26

[Byker28i]

Interesting to see the heater matrix/heater apart

I took the cats out to heavily reduce the heat from the tunnel but the engine does produce a lot of heat.

Which is better for cooling the engine/deflecting the heat away. The early F1 panel sitting low or the later F1 panel sitting high.

I must get around to checking my air intakes aren't blocked, might be a job for today

[pmessling]

Mines a late 04 Mk2 with the round vents. Even with the fans off it gets past, closing the vents doesn’t do much and the cold comes out of different vents.

[pmessling]

phillpot said:

pmessling said:

Ive been trying to find an electronic bypass valve that could be used to divert the coolant from the matrix

Any good? ..... 12 volt 3 port valve


and three of these.

Edited by phillpot on Friday 10th August 22:26

Yes that’s the type of thing. Simple but effective way. I know there is a possibility of a surge of cold water should it be opened in the summer but I guess the coolant would mix quickly

[Luckyone]

Byker28i said:

Interesting to see the heater matrix/heater apart

I took the cats out to heavily reduce the heat from the tunnel but the engine does produce a lot of heat.

Which is better for cooling the engine/deflecting the heat away. The early F1 panel sitting low or the later F1 panel sitting high.

I must get around to checking my air intakes aren't blocked, might be a job for today

I was curious to find out what was in the box so figured some others may be too. Its a shame that lovey aluminium welding is hidden away!

Yes the decats & extra heat shealds do help a lot, it still gets warm though but nothing like it did before.

I’m looking forward to trying it with working A/C (I hope!) soon. ATS have a deal with the groupon website where you can get it regassed for about £30. I took it a while ago but they couldn’t find the details of how much to put in. I have found some details of that on here so it’s going back on Tuesday.

Interesting point about the F1 panel, I don’t know on that one.

I was fully expecting to find loads of leaves both when I took the cold side blower unit out while I was rebuilding it a few years ago & the hot recently but surprisingly there were non!

[Luckyone]

pmessling said:

Mines a late 04 Mk2 with the round vents. Even with the fans off it gets past, closing the vents doesn’t do much and the cold comes out of different vents.

Yes sorry it only occurred to me to look at your profile after!

If it had an air valve / flap you’d need the cold fan on a bit to keep it shut.

Your water valve sounds like it should work well. But (assuming it has a similar set up to the earlier cars) its probably worth talking the big air pipe that runs across the top of the passenger footwell off where it meets the centre console / transmission tunnel to see if there is any kind of flap there, they have been known to get stuck.

[Byker28i]

Luckyone said:

I was curious to find out what was in the box so figured some others may be too. Its a shame that lovey aluminium welding is hidden away!

Yes the decats & extra heat shealds do help a lot, it still gets warm though but nothing like it did before.

I’m looking forward to trying it with working A/C (I hope!) soon. ATS have a deal with the groupon website where you can get it regassed for about £30. I took it a while ago but they couldn’t find the details of how much to put in. I have found some details of that on here so it’s going back on Tuesday.

Interesting point about the F1 panel, I don’t know on that one.

I was fully expecting to find loads of leaves both when I took the cold side blower unit out while I was rebuilding it a few years ago & the hot recently but surprisingly there were non!

I might just attack mine with the leaf blower in suck mode or maybe the dyson first and see what comes out.
When the engine was out I had extra heat deflector material added to the tunnel and where the manifolds/exhaust pipes run to try to keep the heat down in the cabin. I'll be honest I don't know if it's made any difference, but then it's been really hot lately.

[WIL35]

I'm still trying to work out how the heating and cooling system is supposed to work. Mine is a 97 and the 98 model I had before seemed to have better heating control.

Luckyone I have read your threads and have a much better understanding, thank you. However, I have checked that the flap above the passenger footwell is free to move and I blocked the intake hole under the front nearside indicator. With just the cold fan on, I am still getting warm air out of all vents except the driver footwell one on the transmission tunnel. If I put the A/C on, the driver footwell vent is only one that has chilled air blowing out of it.

I can't picture the setup behind the dash that should be directing the airflow, but do my symptoms above suggest there is another mechanism that isn't working?

[Byker28i]

I've got a 97. I definitely get chilled air (aircon) blowing from the foot well vents, the two underdash vents and the drivers vent. I can't say about the screen vents

[ukkid35]

phillpot said:

Any good? ..... 12 volt 3 port valve

That looks far better quality than the usual recommendation - Fiesta HCV

https://www.pistonheads.com/gassing/topic.asp?h=0&...

[Luckyone]

WIL35 said:

I'm still trying to work out how the heating and cooling system is supposed to work. Mine is a 97 and the 98 model I had before seemed to have better heating control.

Luckyone I have read your threads and have a much better understanding, thank you. However, I have checked that the flap above the passenger footwell is free to move and I blocked the intake hole under the front nearside indicator. With just the cold fan on, I am still getting warm air out of all vents except the driver footwell one on the transmission tunnel. If I put the A/C on, the driver footwell vent is only one that has chilled air blowing out of it.

I can't picture the setup behind the dash that should be directing the airflow, but do my symptoms above suggest there is another mechanism that isn't working?

You say you blocked the nearside intake hole under the indicator, I take it you mean just that. Blocking just that hole will have no effect, there is no separation in the front of the car, the big holes for the radiator still let loads of air back up the N/S wing, the whole nose cone will be at a reasonably equal pressure.
You need to block the the gap inside the N/S above the wheel arch. It’s not exactly easy to do though, I used some kind of foam with expanding foam to fill any gaps but was picking expanding foam out of the hair on my arm for ages after!

The drivers footwell vent is right next to to the cold inlet to the air box, so is close enough to have mostly undiluted cold air coming out if it.

Hopefully you found the my post with the pictures of where I’d cut the passenger footwell to make the hot side recirculating, (if you don’t do that you’ll have no heating after blocking the wing) let me know if the pictures didn’t work anymore I think they should they are still in on the same server.

[WIL35]

I have read through your modification guide and I will do that soon. I will also contort myself into the drivers footwell and see where all the air pipes come from and go to. Would like to get cold air coming from the steering wheel vent, not sure why anyone would want warm air coming from there.

Thanks for your posts and research into this subject!

[Luckyone]

WIL35 said:

I have read through your modification guide and I will do that soon. I will also contort myself into the drivers footwell and see where all the air pipes come from and go to. Would like to get cold air coming from the steering wheel vent, not sure why anyone would want warm air coming from there.

Thanks for your posts and research into this subject!

No problem, once its working properly you can get cold coming from any vent. Though you won’t be able to get cold from one & hot from another. The air box behind the dash is just that a big box, one hot feed into it on the passenger side & one cold on drivers. If either one of the two inputs are successfully shut off you’ll just get the output of the other from all the vents that all come out of that box. I’m you have already worked out the more other vents you shut, the more comes out of the ones left open.
It can be nice having just the steering wheel vent open, but having just had the A/C regassed I was too cold with just that vent open the other day so popping the two in middle top of the dash open was just right.

The kids moan they don’t have their own air vents in the back, I think that would be on mod too far though!

[Byker28i]

just open the windows for the back passengers. Huge cooling effect on them then

[Luckyone]

Byker28i said:

just open the windows for the back passengers. Huge cooling effect on them then

Ha yes that it does, my daughters hair goes mad with the windows open! You do have to watch out for puddles though I soaked my niece many years ago...

She fitted nicely last time she was in the back, she is 27 now though & was in the back again the other day again it wasn’t quite so comfy for her this time!

The Cerb has been doing sterling service as a daily driver recently, it’s lovely to be out in it again so much, but it has got some limitations.

At least there are back seats though, I picked my son up from Tennis camp at the very posh local school last week, the Cerb looked right at home parked next to a Jag F-Type R & the other Porsches etc. You should have seen the look on the mum with the Jag’s face as my two got into the back of the Cerb!