After driving my Z for a couple of hundred miles, the radiator level gets a bit low and as soon as i stop the engine it leaks out of the bottom of the expansion filler tube where it joins the tank part. i cannot see anywhere else where it is leaking, i beleive there is a valve to the expansion tank which is not letting water back into the rad if i fill up the expansion tank.

 

Anyone experienced this themselves ?

 

I have read on here about members doing away with the expansion system altogether !?

Dont do away with the bottle, as it is needed, the rad cap has a 2 way valve on it to allow water out when hot and back in when cooling, check the overflow pipe for kinks, also try blasting a hose into the bottle to free up any crap lodged in the bottom of it and finally buy a new rad cap, they are less than a tenner and a very important part of the cooling system.

I had the same problem when the radiator cap wasn't fitting properly as the plastic had worn which effectively dropped the system pressure and allowed it to boil at too lower temperature.

if its none of the above (with your levels dropping low) have you noticed any fogging / humidity in the cabin or on windscreen when you park up after a drive (bit difficult now the weather is better) if so could be your matrix on the way out

Rad cap

Rad cap

 

Ok, will check that and buy a new one

Yep exactly what mine was doing. Replaced the rad cap and all is now well.

 

Darrell

Yep exactly what mine was doing. Replaced the rad cap and all is now well.

 

Darrell

 

Let's hope it that then

Dont go for one off Ebay, there are some Poo ones on there, :headvswal

you dont want to get stung with one thats worse than the one you have already.:nono:

I had a friendly disagreement with someone on here over the expansion bottle and the cap, and I was wrong both twice.

 

However I have binned mine, and after the previous thread I have paid very close attention to my water level and it simply does not use any water.

Part number is ADZ99901 any motor factor should be able top find it with that number if they want more than a tenner for it they are taking the mickey.