How do I do a "dye test" for leaking coolant?

[bull996]

Can anyone tell me how to "dye test" the coolant system please?

I assume I will need to buy a dye, but how do they work? Looked on tinterweb, and I can find the dye, but no instructions...

thanks in advance

[wolfie1978]

Do you mean a sniff test for a leaky head gasket or a test on the quality of the coolant? For a sniff test you'll need a kit which you can get for as little as £40, the other i know nothing about

[Buff Mchugelarge]

Plop it in, run the car and wave a UV lamp around all the joins/pipes etc which should show up any leaks as glowing UV disco type stuff.

[tbc]

does cracking into it work?

[Eggman]

Presumably it's a dye that fluoresces under ultraviolet light?

If so, you'll need to obtain an ultraviolet torch of the right wavelength and check for leaks after dark. A forged banknote detector might work.

[davepoth]

tbc said:

does cracking into it work?

Probably would, and may well help seal the leak, like an egg yolk. That would be a fun repair to try and explain to the police when they get called though.

[bull996]

Thanks for the help.

Will any UV torch do the trick? The inspection UV lamps are £40, I have found a "mid range" torch for £20 and then there are some for £3.99!

[Buff Mchugelarge]

bull996 said:

Thanks for the help.

Will any UV torch do the trick? The inspection UV lamps are £40, I have found a "mid range" torch for £20 and then there are some for £3.99!

yeah, should do. Ultra voilet is ultra voilet.
The difference in price is proberly quality, life span etc

[Fleckers]

or give it a good squirt of fairy liquid and run it up to temp, then look for bubbles

[Rich_W]

bull996 said:

Can anyone tell me how to "dye test" the coolant system please?

I assume I will need to buy a dye, but how do they work? Looked on tinterweb, and I can find the dye, but no instructions...

thanks in advance

FIRSTLY DO NOT PUT ANYTHING INTO THE COOLING SYSTEM OTHER THAN WATER AND COOLANT!!!!

Secondly, UV Dye is used in determinng AIR CONDITIONING leaks. NOT COOLANT

Coolant stains where it leaks and crystalises. So Leaks are easy to see if external (outside of the block) If you are thinking coolant is leaking into the cylinders you need a "Block tester kit" (circa £40ish) like this one

http://www.ebay.co.uk/itm/UNIVERSAL-CYLINDER-HEAD-...

[Eggman]

The leak detecting kits certainly seem very expensive for what they are - see here.

There's an outfit in Horsham called Kent Europe who sell the dye separately in multiples of 6; might be worth chatting to them to establish if a banknote tester would make the stuff fluoresce. I wouldn't bank on it though; I believe that some fluorescent substances only do it at very specific wavelengths.

I once heard a story (probably false) about the Home Office buying a very large quantity of UV lamps for forensic purposes to detect a particular bodily fluid that is sometimes present at crime scenes. Someone took one of the lamps home with the intention of producing a small amount of this fluid (hem) in order to observe it fluorescing, only to discover that it didn't. Turned out they had bought the wrong type of lamp.

[bull996]

I have bought the dye £3.74 for 6 bottles and a UV light for £10.

The leak is just peeing me off now. I do have a block tester kit which was negative.

I have cleaned all the pipes/connectors and cant see any residue, so this is the next step.

Dont know if your interested, but its a Jeep and when I bought it all was fine-used no coolant at all over 3000 miles but ran a bit cool. Turns out the thermostat had been disabled in the OPEN position, so I replaced that with a new one and that sorted the cool running. Its since then that its been losing a litre of coolant every month or so-I guess it could be still burping the air out thats trapped, but I think that would have been done by now. Been under the car when running and cant see anything leaking, checked the front carpet in case its the heater core, but nothing there either. Oil is perfect and no oil in the water, no white smoke out of the exhaust either. Thinking it could be a pinhole leak when hot (level doesnt drop when the car isnt used) hence the dye.

[Jimmyarm]

You want a pressure test kit, they are north of £100 though.

Most mechanics will have one.

[Rich_W]

Heater Matrix or EGR then

Those coolant dye kits are st. If you "must" buy some tools get a pressure testing kit.

http://www.esellit.com/bergen-tools-bergen-profess...

(for example)

Make sure it will fit Jeep though.

[Eggman]

Have you tried fitting a new radiator cap? Tired ones can sometimes make the coolant level fall mysteriously over time.

[bull996]

Eggman said:

Have you tried fitting a new radiator cap? Tired ones can sometimes make the coolant level fall mysteriously over time.

Just bought one, will see how we go.

[bazking69]

Try the cap. Amazing how many times people have scratched their heads (and knuckles) only for it to be down to something so simple as a dodgy seal in the cap.

If not, i'd personally entrust it to a mechanic/garage if you can't see anything obvious. Having a car on a ramp usually aids tracing leaks as gravity coupled with deposits left by dried coolant usually help you to trace.

You could spend a fortune on kit you will never use again when half an hours labour tops at a garage could trace the issue.