Coolant Level Switch Leaking

[JackE]

Hi,

I have a DG 1913 engine, and am fairly new to this! I was just looking at the engine today and notice that a very small amount of coolant was leaking from the area around the level switch, and was wondering what the easiest way of fixing this is. Apart from this minor leak the cooling system seems to be working fine.

It looks very tight to get a socket/spanner in there to undo and replace the switch and if I undo it coolant will come out as the expansion tank is full, if I take the coolant out to swap the switch over I guess the system will need re bleeding as it looks like the hole where the switch goes into is lower than the highest pipe of the tank, I don't really want to have to do this as I have recently had the coolant replaced.

I was just wondering that the easiest way of fixing this is and if there is a short term solution and then long term.

Thanks for reading

[Wychall]

The amount of coolant lost is negligible and it will rebleed itself using water from the expansion bottle the next time you drive the vehicle.

Be aware that a leak in that area is often down to the plastic thread of the level switch actually having fractured so the more that you try to tighten it, the worse the leak will get. I would advise arming yourself with a new switch before trying to tighten it, or be prepared for a few days downtime whilst waiting for a new switch to arrive.

[JackE]

Thanks for your help,
So you would recommend getting a new switch and then taking some of the coolant out and replacing it, is it easiest to use a socket to tighten in?
Sorry for these very basic questions! and thanks again

[Wychall]

When I discovered that my switch had split, I obtained a new switch then used a syrnge to drop the level in the tank to below the switch.
A large socket is best as there is very little access for anything else. Make sure that the sealing ring is in place and fit the new switch. Do not over-tighten as they have a habit of splitting. Oh, sorry, I've already said that, haven't I! It's best to under tighten intially as it will only show up as a leak which you can progressively tighten to prevent.
Once the switch is back in, the coolant that you syringed out can then be replaced and the pressure cap refitted. Now just keep an eye to ensure that the switch is indeed tight enough, and top up the expansion bottle if anything gets used from there after a run.

Good luck with it

[StuM]

I had this with mine too. Used PTFE tape as a temporary 'get me home' fix. Bought a new switch and tank (couldn't convince myself that the tank thread wasn't to blame) and never got around to fitting - tape has kept it bone dry for a year. I will sort - on a long list of winter jobs!

Nb. There are two types of plug fitting on the switches, be sure to buy the right one.

[T3luestar]

I also had the same water build up around the switch, but on further inspection it turned out to be the tank itself. There was lots of very small hair line cracks around the opening for the switch.

[itchyfeet]

I had the same but no cracks on tank or switch (sensor really)
When I looked the corners of the switch 'nut' were touching the tank before the switch seal was compresed
Either a bad copy tank or switch not sure which
I fixed it by filing off the corners

[JackE]

Thanks a lot for your help, hopefully it will just be a switch replacement and I won't have to replace the whole tank. Thanks again