Cooling system details

[rollercoaster]

Been sorting my system,
found loads of issues.

Leftover after a fair bit of new bits:

What sealant to use on the rubber O ring,
sealing the coolant level sensor?
I am still losing steam/fluid there,
cant imagine I need to make it even tighter,
maybe I got the "wrong" seal for the vessel..
It came with the new sensor.

What is the coolant fan relay values?
Mine that came out was 70A
I replaced it with a 40A, it works..
Do I need to look for the "correct" one?
What is it and where can I find it?

Thanks

[Mocki]

You should need any sealant around the level sender , check the bottle for cracks , burrs in the thread 

rad fan relay should be ok at 40a , it’s fused less than that ? 

[Oldiebut goodie]

( I am sure that my fuse was 50A, cable is certainly up to the 70A)

Brickwerks say:
 12V 70A 4 pin relay for T3 radiator cooling fans.
 Fitted above the fuse box on the left front inner A-pillar in a separate relay and fuse holder.
 There is some confusion over the amperage of this item as VW superceeded the part number several times, each supercession ends up with a different amperage rating and a different number on the top.
 Originally this part was 251 919 505 and doesn't have a VW Relay number.
 We have matched an original relay rather than rely on VW information which appears to be flakey at best!
 The numbers listed as OE references below are what VW list through the part supercessions and are to be taken with a pinch of salt!
 The configuration of the terminals remains the same however the amp rating varies wildly, this item is 100% a 70A version and therefore should be suitable if not overkill for the OE references below.

This was my relay and fuse:

[rollercoaster]

You should need any sealant around the level sender , check the bottle for cracks , burrs in the thread 

rad fan relay should be ok at 40a , it’s fused less than that ? 

Hmm yes I agree, you mean I shouldn't need sealer I presume?
but there was sealer, and the level sender was very cracked.
At first I thought it might have been bodged to seal it..
but then with a new sender (and seal) it still leaks a bit,
so thanks for stating the obvious (I hadnt thought of)
I will check for burrs etc.

The relay seems ok at 40, but a 70 came out, and thought to ask,
as I wouldnt want it to stop working, its a bit of a critical component.
And it would be prudent to tape a spare next to it too!
Whatever happened to my system I dont know,
but the relay wasnt working, neither was the fan, even with a new relay.
Level sender wasnt working either, massively cracked..

New fan is the correct one and has lots more blades, two speed,
nice and quiet too.

I'll try and upload a pic of the relay,
the parts place I tried didnt have one rated at 70A,
but thanks Oldie, if its 70A definitely, I might be able to order one.
Would it hurt to use an over rated one, I imagine not?


 

[rollercoaster]

[Oldiebut goodie]

No problems with using an over rated one - it is using an under rated one that could lead to problems.

[rollercoaster]

Ordered the Brickwerks 70A relay,

just need to know what sealant to potentially use,
on the rubber O ring of level sender?

Ordered another O ring anyway cut its cheap,
and will dismantle that once its arrived,
and check the sealing surfaces etc.

[Aidan]

you could try a few wraps of ptfe tape if necessary

[rollercoaster]

Thats a great idea,
I will check with my bro whos a plumber too,
he uses something he rates highly,
a locktite version I believe.
Its got to withstand the temperature ..

Anyhow I did check and smooth surfaces,
so I tightened it up a touch more..
could just not be tight enough..
I was sceptical of the plastic threads.