Thread: What radiator should I buy?

to reduce the effects of electrolytic corrosion

Originally Posted by jbarracl

Was the last radiator earthed properly ?

That can cause problems apparently with alloy radiators.

Not just ally ones.

Originally Posted by clankilpatrick

Earthed properly? I have absolutely no idea. How do I make sure?

with a very very sensitive multi meter

Originally Posted by jbarracl

I think you can use a multi-meter and stick one probe on the neg terminal of your battery and the other in the coolant in your radiator and check the reading. What an acceptable reading is, I dont know, you may need to check that out.

Best to just get an earth strap and connect it from your radiator to either a point on your chassis or engine just to be sure.

Maybe if you put a query in the tech section you may be able to get some info from someone with a bit more knowledge than me.

absolutey zero volts is acceptabe but you dont go from the battery you go from the engine block to the coolant in the radiator, this test wont work if you have a suzi and check it in the expansion tank you must check it at thre radiator plug.

Originally Posted by clankilpatrick

Thanks for that idea.
I have used this method before to check the brake and clutch fluid. The higher? (can't remember, have to double check) the reading on the volt meter, the more water is in the fluid so the less effective it works. use as an indicator as to when its time to change the fluid.
cheers
Dave

not quite... what you are looking for is a stray earth current not the resistance of the fluid using the meter on impednace (the resistnace setting) and measuring the resistance can give you an indication of the concentration of the fluid but its wildly inaccurate.

The general rule is the higher the resistance the more water in the fluid in question.

This should ONLY be used for a comparison on your own vehicle checking from one vehicle to another can cause lots of confusion.

Originally Posted by scott oz

Curious why would you earth the radiator

It helps to prevent stray Earth currents,static build up in plasticy radiators and is alleged to also help against electrolisys

Originally Posted by Sprint

to reduce the effects of electrolytic corrosion

see.

Originally Posted by scott oz

I'm thinking of running a dedicated earth the length of the vehicle and removing all the earthing points from the vehicle body, chassie, motor and attaching them to the dedicated earth line.

Am I correct in reading into ELECTROlytic corrosion that it is associated with the fact that the motor is used as an earting point. As such the coolant conducts a small charge to the radiator? Given the radiator is mounted on rubber blocks it should be fairly well insulated from earthing.

thats pretty much it in a nut shell.

In some cases where you have mixed metal engines and cooling systems, using the wrong kind of coolant or using tap water as opposed to demineralised/distilled water you will actually tun your cooling system into a short circuted battery and it will eat the "softest" components in no time. If you have to fill up the cooling system with local tap water go check the public toilets first, stains in the porcilain or crystal growth on/near the taps means that as soon as you can you should dump the coolant and replace it.