help with cooling system/radiator

[macklin]

have a 1983 sigma gj series (old but very usefull)

a couple of days ago I had the cylinder head gasket replaced, ok so far.

the radiator cap looked very old so i decided to have it replaced.

Now the problem, I went to auto mart and asked for a cap for the above model the guy said does your car have a plastic bottle next to the radiator i said yes, why???, he said one cap recycles the water from the radiator to the bottle and the other is if you have had a new radiator put in they throw the bottle away and you need the other type of cap. ok I took the one for the bottle, got home then realised a few years ago I did get a new radiator, so I looked at the plastic bottle ( I figured they decided not to take it out) I could not find any tubes leading to the bottle ???????. ( yes there is another bottle there but it is for the washers). now is it ok for the new cap or will i have to change it for the other type. Will I do any damage if I keep the new cap or should I change it for the other one without the bottle. Just exactly what is the difference I am totally at a loss.


thank you

john macklin

[pipeclay]

im not a mechanic so my wording will be incorrect,you will probably find the pressure of the cap you purchased is slightly lower than the type that does not use the bottle,have a look at the top of your radiatir where the cap fits,if it has a pipe coming out of the neck you can go back to the bottle,you will need to get new tubing or hose if its not there(make sure if the pipe is there that it is open there is a chance that it may be sealed) if theres no pipe there you will have to you the cap that suits the non recovery system,if you dont fit the correct cap when the radiator is at correct opperating temp you will lose water.

[macklin]

thank you pipeclay for your reply.

there is indeed a pipe coming from the top of the radiator next to the cap and going to the bottle. Now for the bad news :(( the bottle I thought was for the washers was in fact the bottle for the radiator, so I put some kind of soapy window cleaner in there :no: I will empty it out tomorrow and hope no damage done. I did not look properly :doh:

thank you

john macklin

[dazzler]

Hi John

This is how it works;

As the water gets hot in the engine it expands and some travels past the radiator cap along the tube and into the plastic bottle.

When it cools it sucks back through the hose and into the radiator maintaining the same water capacity in the radiator/engine.

You can tell the difference between the caps by turning them over. The new style that you should have will have a thick rubber ring about 5mm thick whereas the old one wont.

Use the one with the ring and fit a new piece of hose. It must be a very snug fit as it uses vacuum to suck the water back.

A good radiator place such as natrad will be able to help with the correct pipe.

Having said that, provided you check your water in the radiator each time you fill the car up with petrol then you will be fine. Just remember to check it when cold or at least release the pressure by turning to the first notch to release the pressure before removing.

good luck

[macklin]

thanks dazzler.

is it ok if i empty the bottle i thought was the washer, but was in fact the radiator or just leave it to mix with the radiator water (see my last post)

thanks

john macklin

[dazzler]

Drain it and refill with ready mixed coolant once the hose has been replaced.

:)

[macklin]

OK thanks, will do


john macklin