w126 500 sel 1992 coolant leaking from transmission coolant radiator connector

Steve Bays

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Hi,
i have coolant leak that coming from a lower hose that connects to the transmission.
Is it a case of sealing the brass nut, or could the radiator be knackered?
 

Blobcat

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Hello and welcome

Depends really where the leak is coming from, is it the joint, the hose or the rad?

You could try the joint first, see if it’s loose or if the hose is leaking.
 

LostKiwi

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Hi and welcome.

It sounds to me like the radiator is knackered. If it's coolant leaking it suggests the fitting in the radiator is cracked. Tightening the fitting could make it worse. If it leaks ATF then tightening it may help.
 
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Steve Bays

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it was dripping from the hose but, so I wasn't sure whether it was from the nut, hose or pipe.
I have removed the radiator, ordered a new hose.
is there a good way of checking the rad before I refit?
 

Blobcat

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it was dripping from the hose but, so I wasn't sure whether it was from the nut, hose or pipe.
I have removed the radiator, ordered a new hose.
is the a good way of checking the rad before I refit?
Seal up the bottom hose outlet and fill it with water. If it leaks then the rad has a hole
 

LostKiwi

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Pressure testing is the best way to check it.
 
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Steve Bays

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as the rad is now out of the vehical I'm thinking, of buying two hoses, one for the small outlet and one for the large outlet, place a plastic bag over hole, secure hose around hole and tighten union clip to seal up holes, I take it I don't need to worry about sealing up the transmission holes.
Then fill the rad with water, and watch to see if the transmission connectors leak.
Or is there a better way, I'm not a mechanic, just a practical person.
 

LostKiwi

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Normally you'd seal the water outlets then pressurise through the radiator cap if there is one.
I've used garden hoses in the past but that depends on your water pressure.
 
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Steve Bays

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When I had the car serviced the air con rad, was leaking and needs replacing.
Should I do that at the same time?
Is this an easy job as I suspect.
 

LostKiwi

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You may as well. It's all in same area. With care it's not normally a difficult job. Just be careful not to cross thread connections when putting them back in.
 


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