Important! : Small hole in neck of new Nissens radiator - what goes in it? - Saxperience

JRC1 · 23rd May 2010, 17:23

As above, just finished fitting my Nissens rad and noticed that there is a small hole in the neck of the radiator (see pic below)...

Does anything go in this hole? Because at the moment it's just chucking out coolant when running and when the engine is turned off....

Thanks...

raunchz · 23rd May 2010, 17:26

I've never seen that before

JRC1 · 23rd May 2010, 17:27

Quote:

Originally Posted by raunchz

I've never seen that before

I'm baffled! It's a brand new Nissens rad off 106parts.com. There isn't that hole in my old VTS rad... Not sure what to do lol

vtrlogan · 23rd May 2010, 18:07

isnt it like a presure relife?

Baz · 23rd May 2010, 18:08

not sure but got it in my rad and my old rad, works fine though with it

don't worry about it

JRC1 · 23rd May 2010, 18:17

Quote:

Originally Posted by vtrlogan

isnt it like a presure relife?

Quote:

Originally Posted by Baz

not sure but got it in my rad and my old rad, works fine though with it

don't worry about it

So it doesn't have to be filled in? Surely coolant will just keep getting lost though.. Like when going around corners and over bumps etc?!

Thanks.

vtrlogan · 23rd May 2010, 18:21

the hole system will have a certain persure with the hole, will stop you from blowing pipes if over filled, and also let the water get out if over filled, shouldnt leak 1 bit if filled correctly

raunchz · 23rd May 2010, 18:22

I was under the impression the cap took care of the pressure in the system ?

I agree with the others though, just looks like an overflow hole? OR pressure hole

Meto · 23rd May 2010, 18:23

I would guess at it being a pressure release like said. On my standard radiator the max line is nowhere near the top, so even when the water expands when hot, the water shouldn't be near the top. But I don't know where the max line is on a nissens.

So I don't think any water would leak out when driving, as its only a small hole.

JRC1 · 23rd May 2010, 18:30

Quote:

Originally Posted by vtrlogan

the hole system will have a certain persure with the hole, will stop you from blowing pipes if over filled, and also let the water get out if over filled, shouldnt leak 1 bit if filled correctly

I guess I filled it up too much then. I'm sure the water level of my old VTS rad was usually right near the top so I did the same with this one...

Quote:

Originally Posted by raunchz

I was under the impression the cap took care of the pressure in the system ?

I agree with the others though, just looks like an overflow hole? OR pressure hole

Ah, thats good to hear, seems like it's nothing to worry about then.

Quote:

Originally Posted by Meto

I would guess at it being a pressure release like said. On my standard radiator the max line is nowhere near the top, so even when the water expands when hot, the water shouldn't be near the top. But I don't know where the max line is on a nissens.

So I don't think any water would leak out when driving, as its only a small hole.

I'm sure the max line will be the same on a Nissens to a standard? I'll go outside and have a look in a min. I guess I just filled it up too far! I am just worried that when the water gets hot it's going to run up the tube and spray out into the bay!

Cheers for the input guys

Gareth_R · 23rd May 2010, 19:18

as long as the cap is the correct one it will have a spring on to allow the inner part of the cap (the part that seals) to move up and down. if its overfilled and the pressure gets too high, the inner part lifts up, allowing excess coolant to escape out of that hole. If its at the right level you should get any coming out of it. You definitely wont get coolant leaking out of there just by going round corners

Liam_ · 23rd May 2010, 19:22

The max level is way below that hole, should be marked on the bottle.

I imagine the hole is probably to aid bleeding.

tweeqd · 23rd May 2010, 20:04

the cap does sort the pressure, when fitted the cap comes lower than that hole, when the pressure is exceded the spring in the cap lifts to expose the hole letting out excess air or coolant so as to keep the system at the correct pressure

JRC1 · 23rd May 2010, 20:51

Quote:

Originally Posted by tweeqd

the cap does sort the pressure, when fitted the cap comes lower than that hole, when the pressure is exceded the spring in the cap lifts to expose the hole letting out excess air or coolant so as to keep the system at the correct pressure

I've just given the cap another turn as it wasn't tight enough and now it's as far round as it can go. It's kind of covering half of the hole, but not all of it. The coolant level is just below the max marking now so hopefully it will be ok.

Stevo123 · 24th May 2010, 13:31

My Mk1 standard rad was like that as well. When pressure is higher than the cap springs pressure it will escape past the caps rubber seal and vent through that hole as mentioned above.