Replacing heater hoses on The Hoe

Offgrid · Jul 7th, 2023, 11:29

The Hoe ( 1990 740 estate with B200e engine) has a serious water leak from the upper heater hose. It looks as if it is a fairly easy jobe to replace the hose ( or maybe both heater hoses ), but I've only found one source for a contoured hose, and it looks as if it is a rubber one. It also costs £20, which seemed a bit high to me. I'm considering buying a length of silicone hose, and fitting that. It's a lot cheaper, and looks as if it could be better quality. Assuming I can fit it without kinking the hose, do you think that this would be a good option? If I do go for this, should I protect the hose with silicone hose preservative?

griston64 · Jul 7th, 2023, 12:19

Quote:

Originally Posted by Offgrid

The Hoe ( 1990 740 estate with B200e engine) has a serious water leak from the upper heater hose. It looks as if it is a fairly easy jobe to replace the hose ( or maybe both heater hoses ), but I've only found one source for a contoured hose, and it looks as if it is a rubber one. It also costs £20, which seemed a bit high to me. I'm considering buying a length of silicone hose, and fitting that. It's a lot cheaper, and looks as if it could be better quality. Assuming I can fit it without kinking the hose, do you think that this would be a good option? If I do go for this, should I protect the hose with silicone hose preservative?

£20 is cheap ! Check out the price of a gen Volvo heater hose !!

Offgrid · Jul 7th, 2023, 15:34

Thanks for the reply. I decided to buy the contoured pipe, as it does have to wriggle around a bit behind the engine. It looks as if the old hose failed because the fitter had over tightened the jubilee clip, and it had cracked the end of the hose over time.

Jimsiss · Jul 7th, 2023, 18:46

I replaced one of my 940 heater hoses a few years back with a cheap unbranded hose, it was wrapped around the outside and it split this year right along one of the wrap lines.

Replaced it with a Do88 silicone LHD hose. Took a couple of well measured cuts to get it to fit but mine is an air con car so it was luckily where the heater valve would have been (mine broke and I replaced it with a short section of stainless tube I had spare). Not had the chance to replace the remaining original hose as it wouldn’t come off the heater matrix so I left it for now.

I bought some silicone hose (5/8” (16mm ish) bore if I remember correctly) to make up any sections I couldn’t sort in pre formed hoses but haven’t needed it yet. Not sure I’d trust making a full hose out of it as the bends are very tight and the hose will kink and most likely rub on everything.

Offgrid · Jul 8th, 2023, 14:05

I've bitten the bullet, and ordered one now, so I'll see how it goes. I sometimes get surplus copper plumbing elbows and jubilee clips, and I was tempted to try using a couple of thiose with some silicone hose. As it must be fairly low pressure, I might try that if I have to replace some other hoses.

Offgrid · Jul 12th, 2023, 13:39

Well I received the hose, and it was the correct one. I started to try to replace it, only to find that it is the lower hose that is split. Thuis was after removing the distributor and some other bits to get to the screws on the jubilee clips. It looks as if the lower hose is routed over the upper hose for some reason, and I didn't look close enough when analysing the problem. So now I'm trying to find a replacement lowe hose, which is about half the length. Somfar the only one I have found is on offer for £120, and I didn't check to see if the includes VAT or a free house.

I'm in Sainsbury's cafe, and I'm getting stressed by it all. I bought a vegetable lasagna, which appears to be about 2/3 of the size offered last month. I'm going to have to go back to the car and see if I can make a replacement from some generic silicone hose.

The good news is that the extra lift bonnet on the 740 is brilliant, and was a great help when fiddling around behind the engine. The Hoe is a 1990 745 with a B200E engine, and most of the parts checkers seem to think that only B230 engines were available for the 745s. Have I got a special economy version?

Chris1Roll · Jul 12th, 2023, 14:18

Many years ago one of the hoses on my 87 745 GLE rubbed through while I was on my way to work, I didn't even notice until I stopped and then noticed that the temp gauge was pegged!
After getting towed home, we cut out the small section that was rubbed through and inserted a short section of 15mm copper pipe.
The car went on to do another 80-odd thousand like that.

A slightly better option, given how thin walled and distortable copper pipe is these days, is that amazon sell brass 16mm barbed couplers for a few pounds, there is currently one on my car to temporarily loop out the leaky heater control valve.

https://www.amazon.co.uk/sourcing-ma...%2C108&sr=8-37

Forrest · Jul 12th, 2023, 18:32

I don't know what Volvo part number you're after. I've only ever dealt with cars with a/c where the (fragile, plastic) heater valve is under the distributor.

If OEM ones are scarce/expensive then try eBay for something more generic that will fit, or could be cut to fit. There seem to be quite a lot of right-angle bend heater hoses by Gates and Thermotec which are listed to fit a whole host of different cars.

Failing that, you could try making your own either out of 5/8" silicone hose which you could bend yourself using moderate heat. Best to have a bending-spring inside it so as not to lose the shape.

Alternatively, you can get heater hose with a wire spiral inside it which you can bend without it deforming. It's nasty stuff to work with but seems very tough. I've got a length of this that you could have if you lived closer. I decided to reuse my originals when I replaced my heater valve as they were not as far gone as I thought.

https://www.ebay.co.uk/itm/353349957331

Offgrid · Jul 15th, 2023, 08:31

I've looked everywhere, and, as I mentioned, the only one I found was £120. In fact it is the lower heater hose that I need, and I seem to have bought the only upper hose in the country for £20 by mistake. I'll keep that for future use. With 2 740s I expect I'll need it in the future. I did look at some you tube videos about shaping straight hoses, and I got quite optimistic. I planned to fill the hose with sand, seal the ends, and then use a heat gun to rehape it. However, further research seems to indicate that once the rubber hose has been vulcanised, it isn't possible to get a permanenbt change to the contours. My current pan is to use a straight hose, and bend it to shape whilst ensuring that it isn't kinked. I'll try to use cable ties to ensure that it isn't touching any hot or abrasive surfaces. I also considered blocking off the heater outlet on the engine. I gather that the heater matrix is a constant flow item, so I wondered if that will have an adverse effect on the engine cooling.

Chris1Roll · Jul 15th, 2023, 09:48

It's not constant flow, the heater control valve shuts off the flow when the heating is off, so doing away with it will have no effect on engine cooling.
I just spent 3 hours stuck on the M5 yesterday with no problems. (An 89 3-series was not so lucky sadly)
Honestly, unless the hose is split lengthways or delaminating or something I'd pinpoint the leak, cut that bit out and join the two ends back together.

Jul 7th, 2023, 11:29	#1
Offgrid Offgrid camper Last Online: Yesterday 20:05 Join Date: Apr 2022 Location: Havant	Replacing heater hoses on The Hoe The Hoe ( 1990 740 estate with B200e engine) has a serious water leak from the upper heater hose. It looks as if it is a fairly easy jobe to replace the hose ( or maybe both heater hoses ), but I've only found one source for a contoured hose, and it looks as if it is a rubber one. It also costs £20, which seemed a bit high to me. I'm considering buying a length of silicone hose, and fitting that. It's a lot cheaper, and looks as if it could be better quality. Assuming I can fit it without kinking the hose, do you think that this would be a good option? If I do go for this, should I protect the hose with silicone hose preservative? __________________ Cinderella ( Cinders ) - 1988 Volvo 740 saloon with B230E engine The Hoe - 1990 Volvo 740 estate with B200E engine The House - 2005 LDV Convoy hightop with Ford Transit turbo engine. Save Old Cars

Jul 7th, 2023, 15:34	#3
Offgrid Offgrid camper Last Online: Yesterday 20:05 Join Date: Apr 2022 Location: Havant	Thanks for the reply. I decided to buy the contoured pipe, as it does have to wriggle around a bit behind the engine. It looks as if the old hose failed because the fitter had over tightened the jubilee clip, and it had cracked the end of the hose over time. __________________ Cinderella ( Cinders ) - 1988 Volvo 740 saloon with B230E engine The Hoe - 1990 Volvo 740 estate with B200E engine The House - 2005 LDV Convoy hightop with Ford Transit turbo engine. Save Old Cars

Jul 7th, 2023, 18:46	#4
Jimsiss Senior Member Last Online: Yesterday 07:14 Join Date: Jul 2012 Location: Northwich	I replaced one of my 940 heater hoses a few years back with a cheap unbranded hose, it was wrapped around the outside and it split this year right along one of the wrap lines. Replaced it with a Do88 silicone LHD hose. Took a couple of well measured cuts to get it to fit but mine is an air con car so it was luckily where the heater valve would have been (mine broke and I replaced it with a short section of stainless tube I had spare). Not had the chance to replace the remaining original hose as it wouldn’t come off the heater matrix so I left it for now. I bought some silicone hose (5/8” (16mm ish) bore if I remember correctly) to make up any sections I couldn’t sort in pre formed hoses but haven’t needed it yet. Not sure I’d trust making a full hose out of it as the bends are very tight and the hose will kink and most likely rub on everything. __________________ 940 B230FT

Jul 8th, 2023, 14:05	#5
Offgrid Offgrid camper Last Online: Yesterday 20:05 Join Date: Apr 2022 Location: Havant	I've bitten the bullet, and ordered one now, so I'll see how it goes. I sometimes get surplus copper plumbing elbows and jubilee clips, and I was tempted to try using a couple of thiose with some silicone hose. As it must be fairly low pressure, I might try that if I have to replace some other hoses. __________________ Cinderella ( Cinders ) - 1988 Volvo 740 saloon with B230E engine The Hoe - 1990 Volvo 740 estate with B200E engine The House - 2005 LDV Convoy hightop with Ford Transit turbo engine. Save Old Cars

Jul 12th, 2023, 13:39	#6
Offgrid Offgrid camper Last Online: Yesterday 20:05 Join Date: Apr 2022 Location: Havant	Well I received the hose, and it was the correct one. I started to try to replace it, only to find that it is the lower hose that is split. Thuis was after removing the distributor and some other bits to get to the screws on the jubilee clips. It looks as if the lower hose is routed over the upper hose for some reason, and I didn't look close enough when analysing the problem. So now I'm trying to find a replacement lowe hose, which is about half the length. Somfar the only one I have found is on offer for £120, and I didn't check to see if the includes VAT or a free house. I'm in Sainsbury's cafe, and I'm getting stressed by it all. I bought a vegetable lasagna, which appears to be about 2/3 of the size offered last month. I'm going to have to go back to the car and see if I can make a replacement from some generic silicone hose. The good news is that the extra lift bonnet on the 740 is brilliant, and was a great help when fiddling around behind the engine. The Hoe is a 1990 745 with a B200E engine, and most of the parts checkers seem to think that only B230 engines were available for the 745s. Have I got a special economy version? __________________ Cinderella ( Cinders ) - 1988 Volvo 740 saloon with B230E engine The Hoe - 1990 Volvo 740 estate with B200E engine The House - 2005 LDV Convoy hightop with Ford Transit turbo engine. Save Old Cars

Jul 12th, 2023, 14:18	#7
Chris1Roll Senior Member Last Online: Yesterday 22:18 Join Date: Aug 2006 Location: Cannington	Many years ago one of the hoses on my 87 745 GLE rubbed through while I was on my way to work, I didn't even notice until I stopped and then noticed that the temp gauge was pegged! After getting towed home, we cut out the small section that was rubbed through and inserted a short section of 15mm copper pipe. The car went on to do another 80-odd thousand like that. A slightly better option, given how thin walled and distortable copper pipe is these days, is that amazon sell brass 16mm barbed couplers for a few pounds, there is currently one on my car to temporarily loop out the leaky heater control valve. https://www.amazon.co.uk/sourcing-ma...%2C108&sr=8-37

Jul 12th, 2023, 18:32	#8
Forrest VOC Member Last Online: Apr 27th, 2024 23:40 Join Date: Feb 2008 Location: Gloucester	I don't know what Volvo part number you're after. I've only ever dealt with cars with a/c where the (fragile, plastic) heater valve is under the distributor. If OEM ones are scarce/expensive then try eBay for something more generic that will fit, or could be cut to fit. There seem to be quite a lot of right-angle bend heater hoses by Gates and Thermotec which are listed to fit a whole host of different cars. Failing that, you could try making your own either out of 5/8" silicone hose which you could bend yourself using moderate heat. Best to have a bending-spring inside it so as not to lose the shape. Alternatively, you can get heater hose with a wire spiral inside it which you can bend without it deforming. It's nasty stuff to work with but seems very tough. I've got a length of this that you could have if you lived closer. I decided to reuse my originals when I replaced my heater valve as they were not as far gone as I thought. https://www.ebay.co.uk/itm/353349957331

Jul 15th, 2023, 08:31	#9
Offgrid Offgrid camper Last Online: Yesterday 20:05 Join Date: Apr 2022 Location: Havant	I've looked everywhere, and, as I mentioned, the only one I found was £120. In fact it is the lower heater hose that I need, and I seem to have bought the only upper hose in the country for £20 by mistake. I'll keep that for future use. With 2 740s I expect I'll need it in the future. I did look at some you tube videos about shaping straight hoses, and I got quite optimistic. I planned to fill the hose with sand, seal the ends, and then use a heat gun to rehape it. However, further research seems to indicate that once the rubber hose has been vulcanised, it isn't possible to get a permanenbt change to the contours. My current pan is to use a straight hose, and bend it to shape whilst ensuring that it isn't kinked. I'll try to use cable ties to ensure that it isn't touching any hot or abrasive surfaces. I also considered blocking off the heater outlet on the engine. I gather that the heater matrix is a constant flow item, so I wondered if that will have an adverse effect on the engine cooling. __________________ Cinderella ( Cinders ) - 1988 Volvo 740 saloon with B230E engine The Hoe - 1990 Volvo 740 estate with B200E engine The House - 2005 LDV Convoy hightop with Ford Transit turbo engine. Save Old Cars

Jul 15th, 2023, 09:48	#10
Chris1Roll Senior Member Last Online: Yesterday 22:18 Join Date: Aug 2006 Location: Cannington	It's not constant flow, the heater control valve shuts off the flow when the heating is off, so doing away with it will have no effect on engine cooling. I just spent 3 hours stuck on the M5 yesterday with no problems. (An 89 3-series was not so lucky sadly) Honestly, unless the hose is split lengthways or delaminating or something I'd pinpoint the leak, cut that bit out and join the two ends back together.

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