Detecting Coolant Leak (UV dye)

[svenedin]

I have a small coolant leak that has defied my efforts to locate thus far. It find coolant in the drip tray under the engine. It is a small leak but annoying and I just cannot locate where it is coming from.

Years ago I had a leak in a modern car and I got fed up with a professional garage (a dealership) saying they could not find the leak. I decided to use some UV fluorescent dye to trace the leak and I found the source extremely quickly.

I am going to do the same thing again. The dye is Ring RLD2 which is for coolant. There is a different dye available for oil/fuel. The dye is harmless and can be left in the system. All you need is a UV light source (e.g a UV torch). I happen to have a UV torch which I use for an unusual purpose. One of my hobbies is watchmaking. Extremely small quantities of oils and greases are used and these are available in a UV fluorescent form. The correct oiling can be checked very easily with a UV torch.

My guess is the leak is coming from the water pump or water pump gasket. I think this because sometimes I find droplets of coolant flung onto the dynamo by the fan. We shall see!

Picture of one drop of RLD2 in a glass of water illuminated by a UV torch.


Stephen

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[svenedin]

I dosed the coolant water with dye and took the car out for a quick run.

I have found one leak already. It seems to explain why the water ended up on the dynamo because the fan blew the drips off. I don't think this is the whole story though as the drips in the drip tray are on the other side.......

The dyed coolant fluoresces green. Interestingly silicone grease fluoresces blue (I used some to make the hoses easier to fit, it does not harm rubber)

Stephen

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[King Kenny]

Well done. It looks a nice clean engine. We used that stuff in the factory I worked in to crack detect components. Try just repositioning the jubilee clip if the hose is OK.

[Chief]

Can't wait to see your car come Halloween

Actually I keep meaning to get some RLD4 to trace a PAS leak on my other car, but since it may end up at the garage I might let them have the fun since they'll likely have to do whichever pipe is leaking anyway

[oliver90owner]

Commonly known as fluorescein.

[svenedin]

Commonly known as fluorescein.

Yes. Also used in eyes to find injuries.

Here is a pocket watch of mine with UV fluorescent greases and oil. The quantities used are miniscule. You can see the jewels fluoresce under UV anyway but of interest the oil has transferred itself from the lever ruby pallets to every tooth of the escape wheel (exactly as intended). I used to work a lot on watches but I am forgetful and careless since my accident so I started to use the Möbius UV greases and oils to check my own work. I love it! Nothing more pleasing than taking such tiny machines and making them run like clockwork! For anyone interested in pocket watches that is a Swiss movement made by the company Revue. A lovely movement. The watch by JW Benson. The balance is perfectly in beat. A balance is like a pendulum, they can be out of beat and limp horribly.

Stephen

https://www.youtube.com/watch?v=kAAqANb8GI8

[svenedin]

But well the Morris is a special mixture of BA, Whitworth and AF. A nightmare of threads. Some really obscure ones. The Swiss made watches with largely interchangeable parts but in lignes (lines). The English watch is not like that. One part only goes in one place. That screw was made for that place and that place only.

if a screw is marred, if the wrong spanner is used on a nut and it is even slightly damaged this is unforgivable. Start again.

Stephen

[svenedin]

Well done. It looks a nice clean engine. We used that stuff in the factory I worked in to crack detect components. Try just repositioning the jubilee clip if the hose is OK.

Thank you. It is indeed an absolutely beautiful l engine in a disaster of an engine bay. it looks nice also but it is the original engine. 1969. A little tired but still 170 psi on all cylinders.

Stephen

[svenedin]

Well done. It looks a nice clean engine. We used that stuff in the factory I worked in to crack detect components. Try just repositioning the jubilee clip if the hose is OK.

That is exactly what I did. I replaced the hoses (the top hose there was split) BUT if you're not really careful it can still leak

Stephen

[svenedin]

Irrelevant to this thread really but I had the rocker cover off to check and tighten the heater stud nuts (in case the leak was there). I sent this to a friend. Do engine flush/cleaners work or are they snake oil? Well I present this after a flush and oil change........immaculate.

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