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LEAKING COOLANT - FAN SWITCH

Posted: Sun Sep 25, 2011 1:12 pm
by marco2002
Hi everyone

This post is not 406 related but i thought I'd post this anyway to see if anyone could help. Thanks in advance....
I have a 106 diesel which i'm trying to sort out hopefully ready for mot next month. I've got a problem with the rad fan switch. Where it screws into the radiator it leaks on one side , the thread (brass) inside the rad on one side seems to have gone. When you screw the fan switch into the rad it will only go so far before it goes round and round i did manage to get it quite tight before it goes loose. I've tried a couple of bodges in the hope of fixing it used a little bit of ptfe plumbers tape on the thread and put a bit of instant gasket around it as well and i put some k-seal in with the coolant as well as its pretty good stuff seals from the inside. Its not leaking much but i guess the pressure in cooling system finds any weakness in the system but you can see it burning off where its dripped onto the front of the car. I was thinking about setting the fan switch in the hole with a bit of glue instead of instant gasket what type of glue could i use? Something with the same strength as araldite? it would have to be waterproof and able to withstand the heat . Once its set in place it will be there for good as the rad is only about a year old it was brand new just before i bought the car so i don't want to ditch it and spend more money. The fan works fine cuts in at right temp. Any ideas or advice appreciated. Cheers

Re: LEAKING COOLANT - FAN SWITCH

Posted: Mon Sep 26, 2011 11:29 am
by jasper5
marco2002 wrote:Hi everyone

This post is not 406 related but i thought I'd post this anyway to see if anyone could help. Thanks in advance....
I have a 106 diesel which i'm trying to sort out hopefully ready for mot next month. I've got a problem with the rad fan switch. Where it screws into the radiator it leaks on one side , the thread (brass) inside the rad on one side seems to have gone. When you screw the fan switch into the rad it will only go so far before it goes round and round i did manage to get it quite tight before it goes loose. I've tried a couple of bodges in the hope of fixing it used a little bit of ptfe plumbers tape on the thread and put a bit of instant gasket around it as well and i put some k-seal in with the coolant as well as its pretty good stuff seals from the inside. Its not leaking much but i guess the pressure in cooling system finds any weakness in the system but you can see it burning off where its dripped onto the front of the car. I was thinking about setting the fan switch in the hole with a bit of glue instead of instant gasket what type of glue could i use? Something with the same strength as araldite? it would have to be waterproof and able to withstand the heat . Once its set in place it will be there for good as the rad is only about a year old it was brand new just before i bought the car so i don't want to ditch it and spend more money. The fan works fine cuts in at right temp. Any ideas or advice appreciated. Cheers

Maybe the threads are alright further back from being screwed all the way in and adding a copper washer and a big dollop of instant gasket may sort it.

You could try soldering the switch in.

Re: LEAKING COOLANT - FAN SWITCH

Posted: Sun Oct 02, 2011 3:28 pm
by marco2002
Thanks Jasper

Got the fan switch sorted.The coolant was leaking out the top hose onto the fan switch only noticed it when i jacked the car and got right underneath moved the top hose and tightened it up a bit more and all is ok. I now have another problem now the temperature warning light comes on now and the rad fan (brand new switch) is intermittant sometimes it works sometimes it doesn't. I was wondering if the the temperature warning light sensor which is located in the thermostat housing is causing the problem? The rad fan is supposed to cut in at 101 degrees C and cut out at 97 degrees C. I tried earthing the sender wire for the temperature warning light and the light goes out when you do this. A new temperature warning light sender is about £15 so might be any easy option to replace and see what happens as there aren't any 106's in the scrapyard just now. The coolant was all replaced and system bled used a header tank, the heater is giving out plenty of hot air inside the car so i don't think its an airlock or thermostat problem. I'll keep you posted. Also found that the inner cv boots are perished and they seem to be quite expensive to replace £30 each per side from eurocarparts. You can buy a whole new driveshaft for £35 each with a 2yr guarantee so maybe that could be an easier option.

Re: LEAKING COOLANT - FAN SWITCH

Posted: Sun Oct 02, 2011 5:11 pm
by poddack
One thought, if the 106 is anything like the 406, do you have air in the coolant anywhere, might just need bleeding properly.

Re: LEAKING COOLANT - FAN SWITCH

Posted: Sun Oct 02, 2011 8:31 pm
by jasper5
marco2002 wrote:Thanks Jasper

Got the fan switch sorted.The coolant was leaking out the top hose onto the fan switch only noticed it when i jacked the car and got right underneath moved the top hose and tightened it up a bit more and all is ok. I now have another problem now the temperature warning light comes on now and the rad fan (brand new switch) is intermittant sometimes it works sometimes it doesn't. I was wondering if the the temperature warning light sensor which is located in the thermostat housing is causing the problem? The rad fan is supposed to cut in at 101 degrees C and cut out at 97 degrees C. I tried earthing the sender wire for the temperature warning light and the light goes out when you do this. A new temperature warning light sender is about £15 so might be any easy option to replace and see what happens as there aren't any 106's in the scrapyard just now. The coolant was all replaced and system bled used a header tank, the heater is giving out plenty of hot air inside the car so i don't think its an airlock or thermostat problem. I'll keep you posted. Also found that the inner cv boots are perished and they seem to be quite expensive to replace £30 each per side from eurocarparts. You can buy a whole new driveshaft for £35 each with a 2yr guarantee so maybe that could be an easier option.

I never replace cv boots on the 106 for the reason you stated, a full driveshaft is just as cheap and a whole lot easier job.

Good news about the leak :D

Re: LEAKING COOLANT - FAN SWITCH

Posted: Mon Oct 03, 2011 4:59 pm
by marco2002
Hi

The leak is sorted but i'm still having the problem with the temperature warning light coming on. The rad fan isn't cutting in before the light comes on as it should. I wish this car had a temp guage so i could see whats happening. I'm going to see if i can get another temperature warning light sender and substitue it and see what happens. The rad fan switch is brand new. I drained all the coolant today and re-filled and bled the system the heater is nice and hot inside the car. Back to the drawing board.......