A coolant recovery system is a good thing, but you don't need one. Indeed, 1200s did not come with one. A15s do not need one either. Unless you are using a near-boiling-point thermostat, which is not recommended.

Without it your engine should still cool properly. The question here is, when your engine overheats, is the coolant level low? Say you fill up the radiator, then drive it for a while, when it gets hot (before it boils over) stop the engine, let it cool down, then check the coolant level. If it is still full, the problem is not a bad cap. On the other hand if it is low, it's leaking out somewhere. The cap seal could be bad, a hose clamp could be leaking, it could be pulled into the cylinders (bad head gasket), etc. A pressure test is called for, which any shop can do. Also I would do a compression test just in case. Stop guessing and buying parts you may not need, and start measuring ...

Quote: This is simply a conversion to a coolant recovery system & i did it in my 1000 sedan. It prevented gradual coolant loss by catching it & returning it to the radiator when it cooled down, & it allowed me to monitor coolant level, hot or cold, without lifting the cap. I like this system, & will be fitting it in my 1000 coupe.
It works for me.

Radiator specialists normally do a free cooling system check if that interests you

Right!!
I will go try this now!! I mean as they say you cant tell a book by its cover so i spose this goes with cars aswell, the radiator looks fine (with a few snaps in the bars) but of course as you say it could be internal...
Tommy, are you still having overheating problems with your car even tho your radiator, head and water are all fine??

My god this post has gone on longer than expected and had more response than i once thought!! Cheers guys!! Its good to know that the 'oldies' do help out the new Datsun owners/fans!!

Thanks
Dave

ok i have 2 things 2 ask, i have checked everythin but then these 2 popped up!!!:
When i take my cap of and rev the engine the coolant seems 2 drop right down 2 the cores. I was old 2 buy a new radiator cap with a rubber seal and an overflow bottle???, is this worth doing??

Also i still have the stock 4 speed and diff runnin on the a15, could it be the engine is workin to hard???

Tommy

Sounds like you need a new mechanic

Anyways, it's very easy to test the radiator flow:
1. When engine is cold, drain all the coolant from the radiator
2. remove the bottom hose from the radiator
3. Cover the bottom outlet with your palm, and fill the radiator with plain water from a hose
4. When radiator is full, quickly remove your palm
- If the water gushes out the same amount as the bottom outlet, that's a good sign
- If the water trickles out, or runs out but in a stream smaller than the size of the outlet, the radiator is partially plugged

This happened to me. The radiator didn't look plugged, but it was. This can cause the suction hose to collapse as well, since the pump is on one side and a restriction on the other.

So all this happened after you put a new second hand radiator. If thats the only change you have done and this is the result, then this is the problem. Maybe the radiator is blocked? But firstly do you have the right radiator cap and is it sealing? If the coolant isnt under pressure, it will boil at a lower temp.

Get a gemini radiator...$55 for a flushed and sprayed one with 3 months exchange if the thing is crap. You will also be able to use your current hoses....

What fan are you using?

Right....
Have got it back from the guys at the shop and still no go
They said that my bottom radiator hose wasnt tight enough around the seals so they tightend them and that my water pump is ok from a physical and looking perspective but they didnt have time to rip off the front and FULLY inspect it...
The cavities seem to be ok to them and are not blocked with random things...
The only other thing they did mention is that maybe it would be an idea to get another radiator and give that a professional fan or obtain a good new/2nd hand which works well!!

Well driving it home from work this evening it started to heat up again and do the EXACT same thing, graduially heat up as time got along.....
I am really getting shat off about this and will go to the wreakers and radiator place tommorow to get quotes or get it done strait away....
Any other thoughts would be very handy, advice on what i should do or things/problems that people have had realating to this topic would go down a treat

Thanx again
Dave