Expansion tank cap green vs.black

Post by **misha** » 19 Aug 2020, 12:21

I just replaced expansion tank because the old one had a hairline crack on return sleeve and it was seeping coolant a bit....slow seep but i wanted to sort that out.

The replacement is original Volvo,used one,but it came with green cap.Pressure is the same...150kpa.

I swapped my old black cap just in case.
Green cap is also genuine Volvo but underside is a bit different than my original black cap.

Is it improved cap or something since i don't have any problems with my,still original,black cap?

Cookeh · Post by **Cookeh** » 19 Aug 2020, 14:05

Its an improved cap, designed to amend the issues with the caps developing cracks and ultimately leaking.

Mines been on the car for 3+ years, if you're also seeking personal experiences.

Post by **misha** » 19 Aug 2020, 14:08

Mine black cap is still original....no cracks,no leaks,maintains pressure.

Cookeh · Post by **Cookeh** » 19 Aug 2020, 14:20

That's excellent, but I was merely answering your question: green is an improved version of the original. If your black one works then that's good news and means you have a spare improved one just incase your black one succumbs to the issues that plague the majority of them.

In the UK I cant personally recall ever seeing a black one (certainly an uncracked one!), and the green ones have been replacement parts since the late S/V/C70 years.

Post by **misha** » 19 Aug 2020, 14:25

Somebody said...long time ago here on MVS....that all black caps were born bad and should be replaced with green one...but i don't remember for what reason.

Thanks ...i'll keep the green one for spare...since the original black one is ok.

Post by **June** » 19 Aug 2020, 15:09

The black cap is 75kpa which is half the pressure of the green. You can buy black caps from Volvo still. June

Post by **misha** » 19 Aug 2020, 15:15

Nope...my original black cap is 150kpa just like green one.