Amazon: Heater box leak in footwells, Radweld?

SvenSomerset · Dec 12th, 2016, 07:50

Hey folks, We've an annoying leak into the footwells from the bottom of the heater box inside the car, tried using some Arbomast to stop it but no dice... a friend suggested that I pop some Radweld into the radiator (well, the expansion bottle) and that'd find its way through the hot water system and plug the leak, any opinions on whether a) that would work, and b) any downsides to using Radweld? Please advise, soonest! Cheers, Joss

mocambique-amazone · Dec 12th, 2016, 08:47

Hy Joss, Arbomast can't work.
shure it is fluid from the engine?
Don't use radweld, this sh.. stuff you can use if you want to scrap the car in the next few month. It will glue and destroy the heater valve. Do put it in the expansion bottle is without sense. will never work.
Do get out the heater matrix of a Amazon is not really difficult.
In front of check the water line scarefully. If the matrix is corroded your car will have other problems too.
First thing to do:
Remove the water lines from the heater and build a short circuit with some copper tube. You will be able to drive the car (to the garage or...)
Good luck, Kay

Derek UK · Dec 12th, 2016, 11:33

There is a short moulded rubber tube which fits into a hole at the bottom of the heater box. This drains any water that collects in the bottom of the box and runs through a hole in the floor. Yes. this can be a leak from the matrix and if so you will often be able to smell the anti-freeze, but can also be from heavy rain. Carefully check under the bottom edge of the heater inside the car, there is a small gap between the heater and the mat. If extra carpeting has been fitted it's easy to break it off or pop it out of the hole in the floor. If it has been broken off beware that if you try and replace it, that originally there is a small plastic sleeve fitted that makes the grommet part of the tube a snug fit in the hole to minimise leaks. Bottom of the box can be rusty. It's a pain to have to take the whole heater box out just to renew this part so pushing the broken bit up into the box and then fitting a new one with some sealant is a method that can be used. Brookhouse has the tube but I doubt if it comes with the plastic piece.
http://www.classicvolvoparts.co.uk/p...7&page=A_Hoses
If it is the matrix then the box will have to come out anyway.
Make sure the drain pipe that runs down the side of the heater under bonnet is clear.

SvenSomerset · Dec 12th, 2016, 11:55

Thanks, Derek, is this the part I'd want? Come to think of it, reaching behind the bottom of the heater box, there did seem to be a central 'hole' in the box on the firewall side, is that where the hose you're talking about should go? Maybe when I had the heavy rubber mats up during the summer, to dry out the floor pan, they knocked the hose out!

mocambique-amazone · Dec 12th, 2016, 13:15

Yes Joss. You should check first what kind of water is comming out! If it's not coolant water you will solve the prob with this peace of rubber, I asked you for about beeing shure if it's coolant for that reason.
The heaterbox is easy to remove in relation to a P1800 or newer volvos. Don't and never listen to people which speak about radweld and a historic car in one sentence!
You will have knocked out and destroyed the small peace of rubber hose if you removed the rubber floor mats and didn't know about this item.
Good luck, Kay

SvenSomerset · Dec 12th, 2016, 13:58

Quote:

Originally Posted by mocambique-amazone

Yes Joss. You should check first what kind of water is comming out! If it's not coolant water you will solve the prob with this peace of rubber, I asked you for about beeing shure if it's coolant for that reason.
The heaterbox is easy to remove in relation to a P1800 or newer volvos. Don't and never listen to people which speak about radweld and a historic car in one sentence!
You will have knocked out and destroyed the small peace of rubber hose if you removed the rubber floor mats and didn't know about this item.
Good luck, Kay

Apologies for not replying sooner, Kay! Yes, it's coolant, so it'll be that pipe – it may just have come out and still be sticking out through the transmission tunnel... many thanks, folks!

Derek UK · Dec 12th, 2016, 14:57

Having the rubber drain fitted properly may solve your wet floor but won't cure the leaking matrix. Yes, it is the one you pictured. If you are sure that the fluid is coolant, the matrix will need to be removed and repaired. The fault is often where one of the pipes for the hoses are soldered into the matrix casing. This comes about if the pipe is yanked about when you are trying to remove a stuck hose. How easy it is to repair will depend on the size of the split. Will need a heavy duty soldering iron and maybe a hot air gun too. If there is an old school radiator shop near you it should be a piece of cake for them. If no cracks show, have it pressure tested. For DIY, an old bicycle inner tub can be used across the 2 pipes. Put the matrix under water and pump up the valve with a few pounds. Watch for bubbles.

SvenSomerset · Dec 12th, 2016, 15:27

Ah, thanks for enlightening me, Derek! Well, I'll try and refit the hose, or buy a new one, and then keep an eye on the coolant level until the New Year, when I'll talk to our local mechanic, who'll doubtless be able to repair the matrix - he worked a lot on Amazons back in the day... I should add that the leak only occurs when the heater vents are in the 'open' position, not when they're closed, does that mean it still may be the matrix or pipes leaking, rather than just the drain pipe missing?

Derek UK · Dec 12th, 2016, 17:36

A few variables there. If the flap on the heater to floor vent has very good seals it might just stop large amounts of fluid getting through but it would still drain out of the tube or the hole for the tube. If the tube/hole is blocked there is very little room for the fluid to pool before it spills out of the air vent. If the matrix is leaking somewhere your coolant level will go down at about the same rate as the leak. That will be hard to judge but do keep an eye on the coolant level.
If the heater valve is leaking you'll find it dripping on the pedals and your feet, the drivers that is.

SvenSomerset · Jan 22nd, 2017, 00:58

Went out for a nice trip to Warminster today, it was freezing cold so I put the heater on – when I looked in the old takeway tub I'd jammed under the bottom of the heater box, after getting home, the liquid in there was a manky brown-ish colour, not in any way resembling the 'blue' coolant we use. So I guess it's just a new rubber drain pipe that's needed after all! I had a poke around the back of the heater box when I jammed the plastic container under there and located what may indeed have been the old pipe, which likely got pushed back into the box when I had the front mats peeled back... what mastic/sealant would be best for coating the 'box' end of the drain pipe when fitting a new one?

Dec 12th, 2016, 07:50	#1
SvenSomerset Member Last Online: Oct 10th, 2018 15:02 Join Date: Sep 2015 Location: Somerset	Amazon: Heater box leak in footwells, Radweld? Hey folks, We've an annoying leak into the footwells from the bottom of the heater box inside the car, tried using some Arbomast to stop it but no dice... a friend suggested that I pop some Radweld into the radiator (well, the expansion bottle) and that'd find its way through the hot water system and plug the leak, any opinions on whether a) that would work, and b) any downsides to using Radweld? Please advise, soonest! Cheers, Joss

Dec 12th, 2016, 11:55	#4
SvenSomerset Member Last Online: Oct 10th, 2018 15:02 Join Date: Sep 2015 Location: Somerset	Thanks, Derek, is this the part I'd want? Come to think of it, reaching behind the bottom of the heater box, there did seem to be a central 'hole' in the box on the firewall side, is that where the hose you're talking about should go? Maybe when I had the heavy rubber mats up during the summer, to dry out the floor pan, they knocked the hose out! Last edited by SvenSomerset; Dec 12th, 2016 at 12:46.

Dec 12th, 2016, 13:15	#5
mocambique-amazone Master Member Last Online: Jan 24th, 2022 17:08 Join Date: Nov 2008 Location: small village in the north of Germany	Yes Joss. You should check first what kind of water is comming out! If it's not coolant water you will solve the prob with this peace of rubber, I asked you for about beeing shure if it's coolant for that reason. The heaterbox is easy to remove in relation to a P1800 or newer volvos. Don't and never listen to people which speak about radweld and a historic car in one sentence! You will have knocked out and destroyed the small peace of rubber hose if you removed the rubber floor mats and didn't know about this item. Good luck, Kay Last edited by mocambique-amazone; Dec 12th, 2016 at 13:18. Reason: sh... mobile

Dec 12th, 2016, 15:27	#8
SvenSomerset Member Last Online: Oct 10th, 2018 15:02 Join Date: Sep 2015 Location: Somerset	Ah, thanks for enlightening me, Derek! Well, I'll try and refit the hose, or buy a new one, and then keep an eye on the coolant level until the New Year, when I'll talk to our local mechanic, who'll doubtless be able to repair the matrix - he worked a lot on Amazons back in the day... I should add that the leak only occurs when the heater vents are in the 'open' position, not when they're closed, does that mean it still may be the matrix or pipes leaking, rather than just the drain pipe missing? Last edited by SvenSomerset; Dec 12th, 2016 at 15:53.

Dec 12th, 2016, 08:47	#2
mocambique-amazone Master Member Last Online: Jan 24th, 2022 17:08 Join Date: Nov 2008 Location: small village in the north of Germany	Hy Joss, Arbomast can't work. shure it is fluid from the engine? Don't use radweld, this sh.. stuff you can use if you want to scrap the car in the next few month. It will glue and destroy the heater valve. Do put it in the expansion bottle is without sense. will never work. Do get out the heater matrix of a Amazon is not really difficult. In front of check the water line scarefully. If the matrix is corroded your car will have other problems too. First thing to do: Remove the water lines from the heater and build a short circuit with some copper tube. You will be able to drive the car (to the garage or...) Good luck, Kay

Dec 12th, 2016, 11:33	#3
Derek UK VOC Member Last Online: Yesterday 17:06 Join Date: Jul 2006 Location: Chatham	There is a short moulded rubber tube which fits into a hole at the bottom of the heater box. This drains any water that collects in the bottom of the box and runs through a hole in the floor. Yes. this can be a leak from the matrix and if so you will often be able to smell the anti-freeze, but can also be from heavy rain. Carefully check under the bottom edge of the heater inside the car, there is a small gap between the heater and the mat. If extra carpeting has been fitted it's easy to break it off or pop it out of the hole in the floor. If it has been broken off beware that if you try and replace it, that originally there is a small plastic sleeve fitted that makes the grommet part of the tube a snug fit in the hole to minimise leaks. Bottom of the box can be rusty. It's a pain to have to take the whole heater box out just to renew this part so pushing the broken bit up into the box and then fitting a new one with some sealant is a method that can be used. Brookhouse has the tube but I doubt if it comes with the plastic piece. http://www.classicvolvoparts.co.uk/p...7&page=A_Hoses If it is the matrix then the box will have to come out anyway. Make sure the drain pipe that runs down the side of the heater under bonnet is clear.

Dec 12th, 2016, 14:57	#7
Derek UK VOC Member Last Online: Yesterday 17:06 Join Date: Jul 2006 Location: Chatham	Having the rubber drain fitted properly may solve your wet floor but won't cure the leaking matrix. Yes, it is the one you pictured. If you are sure that the fluid is coolant, the matrix will need to be removed and repaired. The fault is often where one of the pipes for the hoses are soldered into the matrix casing. This comes about if the pipe is yanked about when you are trying to remove a stuck hose. How easy it is to repair will depend on the size of the split. Will need a heavy duty soldering iron and maybe a hot air gun too. If there is an old school radiator shop near you it should be a piece of cake for them. If no cracks show, have it pressure tested. For DIY, an old bicycle inner tub can be used across the 2 pipes. Put the matrix under water and pump up the valve with a few pounds. Watch for bubbles.

Dec 12th, 2016, 17:36	#9
Derek UK VOC Member Last Online: Yesterday 17:06 Join Date: Jul 2006 Location: Chatham	A few variables there. If the flap on the heater to floor vent has very good seals it might just stop large amounts of fluid getting through but it would still drain out of the tube or the hole for the tube. If the tube/hole is blocked there is very little room for the fluid to pool before it spills out of the air vent. If the matrix is leaking somewhere your coolant level will go down at about the same rate as the leak. That will be hard to judge but do keep an eye on the coolant level. If the heater valve is leaking you'll find it dripping on the pedals and your feet, the drivers that is.

Jan 22nd, 2017, 00:58	#10
SvenSomerset Member Last Online: Oct 10th, 2018 15:02 Join Date: Sep 2015 Location: Somerset	Went out for a nice trip to Warminster today, it was freezing cold so I put the heater on – when I looked in the old takeway tub I'd jammed under the bottom of the heater box, after getting home, the liquid in there was a manky brown-ish colour, not in any way resembling the 'blue' coolant we use. So I guess it's just a new rubber drain pipe that's needed after all! I had a poke around the back of the heater box when I jammed the plastic container under there and located what may indeed have been the old pipe, which likely got pushed back into the box when I had the front mats peeled back... what mastic/sealant would be best for coating the 'box' end of the drain pipe when fitting a new one?

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)