BW35 autobox in 1800ES

[cassell]

Owing to the connection unions being seized solid at both ends I had to sadly cut the two steel braided transmission oil cooler hoses on my automatic ES to remove the radiator for some timing gear and camshaft replacement work.

These hoses are no longer available as a Volvo part so I'm going to try and have some made up by a hydraulic hose specialist ready for the rebuild although finding the correct unions is proving difficult. Has anyone experience or a recommendation of having such parts made up, and in the interim I wondered if anyone has ever simply looped the oil cooler pipes on the gearbox together on a BW35 equipped 1800, Amazon or 140 model and done away with the cooler system?

I recall that in the 70s an automatic transmission oil cooler was an on-cost option on Volvo 140/145 models equipped for towing purposes so presumably it wasn't deemed necessary for normal use. However it seems that the ES always had a cooler loop fitted into the radiator. I only ever use my ES for short distance gentle driving nowadays so wondered if there's any detriment in not having the oil cooler fully plumbed in?

Any thoughts, experiences or recommendations will be very welcome.

[Othen]

Originally Posted by cassell

Owing to the connection unions being seized solid at both ends I had to sadly cut the two steel braided transmission oil cooler hoses on my automatic ES to remove the radiator for some timing gear and camshaft replacement work.

These hoses are no longer available as a Volvo part so I'm going to try and have some made up by a hydraulic hose specialist ready for the rebuild although finding the correct unions is proving difficult. Has anyone experience or a recommendation of having such parts made up, and in the interim I wondered if anyone has ever simply looped the oil cooler pipes on the gearbox together on a BW35 equipped 1800, Amazon or 140 model and done away with the cooler system?

I recall that in the 70s an automatic transmission oil cooler was an on-cost option on Volvo 140/145 models equipped for towing purposes so presumably it wasn't deemed necessary for normal use. However it seems that the ES always had a cooler loop fitted into the radiator. I only ever use my ES for short distance gentle driving nowadays so wondered if there's any detriment in not having the oil cooler fully plumbed in?

Any thoughts, experiences or recommendations will be very welcome.

It might be easier to fit an aftermarket oil cooler somewhere at the front of the motor car and connect it up with some hose that you could get made up by a hydraulic fitting supplier.

Alan

[Derek UK]

There are many other car makes/models that used the BW35 so I would think that the unions are out there somewhere. I wouldn't think that the unions at the rad end are anything special. Having said that, as you say, the cooler probably isn't essential for casual classic running around.

[Othen]

Originally Posted by Derek UK

There are many other car makes/models that used the BW35 so I would think that the unions are out there somewhere. I wouldn't think that the unions at the rad end are anything special. Having said that, as you say, the cooler probably isn't essential for casual classic running around.

I wasn't suggesting no cooler at all, but an aftermarket one, something like this:

https://www.ebay.co.uk/itm/363694280...YAAOSwnRZgiS1j

... just an example, there are lots on the market, I don't know anything about this particular one.

Alan

[Clan]

Originally Posted by cassell

Owing to the connection unions being seized solid at both ends I had to sadly cut the two steel braided transmission oil cooler hoses on my automatic ES to remove the radiator for some timing gear and camshaft replacement work.

These hoses are no longer available as a Volvo part so I'm going to try and have some made up by a hydraulic hose specialist ready for the rebuild although finding the correct unions is proving difficult. Has anyone experience or a recommendation of having such parts made up, and in the interim I wondered if anyone has ever simply looped the oil cooler pipes on the gearbox together on a BW35 equipped 1800, Amazon or 140 model and done away with the cooler system?

I recall that in the 70s an automatic transmission oil cooler was an on-cost option on Volvo 140/145 models equipped for towing purposes so presumably it wasn't deemed necessary for normal use. However it seems that the ES always had a cooler loop fitted into the radiator. I only ever use my ES for short distance gentle driving nowadays so wondered if there's any detriment in not having the oil cooler fully plumbed in?

Any thoughts, experiences or recommendations will be very welcome.

It is not specifically a cooler it is a heat exchanger .. so the hot coolant warms up the gearbox in your case doing short journeys which helps with fuel economy and the operation of the gearbox . If you end up doing 80 mph for long intervals the gearbox will heat up and then start to dump the heat into the cooling system .
The additional air / oil cooler is for continental trips in hot weather , where some more COOLING capacity is needed by the gearbox , this additional radiator is opened by a thermostat in the system so the oil is not cooled on normal temperature days and conditions .

[Army]

As Borg Warner is a US company I would start by checking for "imperial" / inch based threads. You might find they are BSP - could also be tapered BSP (though that fitting is more often than not used on high pressure systems).

I'd be surprised if a hydraulic shop couldn't figure it out for you - my guess is that these fittings are not likely to be exotic gawd knows what metric based fittings like the ones that Mercedes used in the 1980/90s.

Race car parts / pimp my ride parts sellers often sell adapters that allow you to connect to more popular (ie cheaper) solutions if you don't mind too much about originality.

[Clan]

Originally Posted by Army

As Borg Warner is a US company I would start by checking for "imperial" / inch based threads. You might find they are BSP - could also be tapered BSP (though that fitting is more often than not used on high pressure systems).

I'd be surprised if a hydraulic shop couldn't figure it out for you - my guess is that these fittings are not likely to be exotic gawd knows what metric based fittings like the ones that Mercedes used in the 1980/90s.

Race car parts / pimp my ride parts sellers often sell adapters that allow you to connect to more popular (ie cheaper) solutions if you don't mind too much about originality.

Volvo was Imperial up until 1974

[harvey]

The cooler outlets on the box can be looped together to bypass the cooler, but you will need fittings to do that so you may just as well get fittings to make new pipes at the rad. I don't like the coolers in the rads because they can fail and fill the cooling system with ATF and the gearbox with coolant, and this is expensive to fix, and was a very common problem back in the day. If you're not towing and only doing short journeys you won't have any problems running without a cooler. If you want to keep it the cooler pipes only run at a low pressure. On the Rovers and triumphs of the same period they didn't even have clips holding the hoses to the fittings.

[Othen]

Originally Posted by Clan

Volvo was Imperial up until 1974

... as I am finding out with my newly acquired 1963 Amazon. My American tools are coming in very handy again.

:-)

[cassell]

Thank you for the comments and suggestions everyone, much appreciated. I'd not thought of Clan's explanation about it working as a heat exchanger but it does make absolute sense now.

The unions have unscrewed from the radiator after penetrating oil and gentle firm spanner persuasion so I'm hoping to source new hoses with the BSP fittings as planned. If that fails or takes time at least I know that a loop can be installed at the BW35 without any detriment.

Thanks again all.