Fitting Coolant Alarm to Plastic Radiator Tank

good Q and look forward to reply.
dont know brand but there is one made in WA i think who would have a plan i am sure
rgs
gn

rubnuts


Aerobolt has a few of 'em up to 8mm...
Dunno where you'd get bigger ones in Oz ?
(If ya find out, let me know;-))

For my alarm I used a 4mm stainless steel machine screw with nuts & washers through the plastic top tank. Positioned it just near the top hose inlet spigot where I could get access to insert the screw from inside the tank with the nut on the outside. Ran a pair of nuts onto the screw before insertion to project the electrode 10mm below the tank top. Works a charm.

One thing I did find however was that leakage of coolant occurred up along the thread passing between the screw and nut. Some Loctite on the thread fixed that.

I would not trust a screw or self-tapper screwed through the tank. Nor would I trust an expanding rubber nut. The rubber is not rated for the heat and with time could fail and expose a rather large hole in the tank. At least your alarm would warn you!

Redarc make a unit too - they have a fitment designed for plastic tanks too.
Do I have it right, in that these units use the coolant to ground a circuit ? If so, I guess any means at all that you can establish to get the insulated probe into the top level of the coolant will do. ?

In-line adaptor

Something like this might be the go. It is similar to the set-up that Engine Saver utilises and means that you don't have to alter your radiator at all. They come in various diameters.

Cheers

Roachie

Hi, if your radiator hose is 34mm internal, I have an adaptor to fit. Very similar to the one Roachie listed, but not "GO FAST" purple, it is silver, lol. Let me know if you are interested. John

Had the same problem with my Redarc unit that I purchased. Previously had one in a 60 series which of course had the metal tank. The RV troopy that I now have has the plastic tank. The radiator guy made up a piece of copper pipe with the flanges on both ends (like the radiator has on the top/ bottom inlet/outlet. He welded the nut style fitting to it and the sender just screws in perfect!

Cheers


Mark

This is what you are after.


bay SILVER 38mm adaptor

If you are reluctant or unable to put a hole in your top tank, or if it is a metal tank, an alternative is to place the electrode in the top radiator hose.

Use a 6mm stainless machine screw (full-length thread) positioned at the top of the hose and at least 20mm from the end of the radiator hose spigot. Drill an undersized hole in the hose so that the screw is a tight fit. Use a large-headed screw or place a stainless washer under the head and use a sealant between the head and the washer or coolant may leak up the thread. Use another washer on the outside then use a second nut to secure the cable lug.

At least if you stuff-up the hose whilst fitting the electrode, a new hose is cheap compared to damaging the radiator tank.

I used an Engine Saver (www.enginesaver.com.au) under hose sensor, avaliable seperate from the Engine saver kit, and used it with an Aqua Alert Unit.

Darrin

G'day, the small hole is for the earth lead. John

[fi]/40091.75/Forum/Pic_46[/

$20 on ebay,,, all sizes. Michael