Update your Radiator Cap! 2/7/9 series.

petershen1984 · Post by **petershen1984** » 30 Jan 2007, 04:01

Check under the bonnet - if you have a gray cap on the coolant reservoir, and you have to occasionally add water to maintain coolant levels (in other words, a small leak has developed), please consider replacing the cap with the green ones as seen on later year Volvo 850/940/960s. When your grey cap is about to fail, you might be able to hear steam escaping from the system.

The pictures above will show you the difference between the caps' design.

When the reservoir tank is not air-tight, your cooling system will lose its ability to maintain a high pressure that helps to raise the boiling point of the water/coolant solution. Without this pressure, the coolant will boil and vaporize, and you may have begun to top off the coolant levels occasionally.

It's a precautionary thing - and it's cheap insurance against overheated engine complications. so don't wait for something to happen.

Cheers,

Peter

Post by **billofdurham** » 30 Jan 2007, 15:37

Thank you, Peter.

I had not realised the difference between the old and the new caps.

So far I have not had major problems with my old grey cap, but I have heard hissing which disappeared when I tightened the cap a little. Perhaps this is the start.

Looks like a green cap will be going on my car soon.

Bill.

wojeepster · Post by **wojeepster** » 06 Feb 2007, 18:02

Where does one obtain the green cap?

waynej · Post by **waynej** » 22 Apr 2007, 11:50

It's a good idea to replace your old leaking cap with a new one, but I'd be careful about going to a higher pressure cap. Is everything in the system(heater core etc.) made for the higher pressure? You could be shortening the life of the radiator,heater core or?

Post by **MadeInJapan** » 09 Dec 2008, 19:03

I agree...pressure rating is different. I've read elsewhere not to go up on the pressure due to added stress on other parts in the system- especially if they are old (and most likely they are).

ajs · Post by **ajs** » 02 Jan 2009, 20:31

I replaced my radiator cap with a green one from groton a couple of years ago and has problems with what I considered too much pressure in the system of my 1993 940T. A tiny split occurred in the overflow tank due to the tank ballooning somewhat (ok, I know it is old and this may have been a coincidence) and coolant dribbled out of it everso slowly - but I kept and eye on it and topped up as required. I thought at one point that the head gasket was gone.
In any event, for some reason I replaced the new green cap with the old grey one and the problems seemed to go away - even the split overflow tank was held up much much better.
All this occurred a couple of years ago. I now have a new overflow tank in hand and am waiting for warmer weather before I install it.

Post by **MadeInJapan** » 03 Jan 2009, 10:34

Thank you for posting and welcome to MVS.
What you wrote is exactly what I've been told would happen if you upgrade to the green cap (meant for FWD/AWD Volvo's and not for RWD's). Actually, I'm surprised that more did not happen to your car- you are very lucky.

I'm changing the title of this thread and adding the word, "DON'T," so that others don't get confused and do this potentially detrimental "upgrade" to their cars.

Thanks, once again!
-MIJ

DeRail · Post by **DeRail** » 11 Jan 2009, 15:05

I updated my 760GLE to the green cap (150kPa) but before I did this I checked the rating of the grey cap and it was rated at 150kpa as well at least that's what was written on the cap, is there anything different about these green ones other than the higher pressure?

Post by **billofdurham** » 11 Jan 2009, 16:54

To help make up your minds about whether or not to change to the green cap, which is stronger and longer lasting than the grey one, I have compiled a list of cap pressures for the RWD Volvos.

One note of caution when using this list you must look for your model, year and engine designation. Some engine designations have different cap pressures when used on different models/years. This is how engineers work, they bowl a googly every now and then to keep us on our toes.

Radiator cap pressures Volvo RWD cars:

240.

B200E '84 - '93 1.5bar
B200F '90 - '93 1.5bar
B200K '84 - '89 0.75 - 0.85bar
B230A '84 - '88 0.65 - 0.85bar
B230E '90 - '93 1.5bar
B230F '87 - '92 1.5bar
B230K '86 - '88 1.5bar

740.

B200K '84 - '89 1.0bar
B200E '88 - '89 0.75bar
B200F '89 - '92 1.0bar
B204F '88 - '91 1.5bar
B200ET '84 - '88 1.5bar
B204GT/FT '89 - '91 1.5bar
B230K '84 - '86 1.0bar
B230KH '87 - '91 1.5bar
B230E '84 - '89 1.0bar
B230F '86 - '91 1.0bar
B234F '88 - '92 1.5bar
B230ET '84 - '89 1.5bar
B230FT/GT '86 - '91 1.5bar
D24T '84 - '91 1.0 - 1.5bar
D24TIC '86 - '91 1.5bar

760.

B23ET/230ET '82 - '90 1.5bar
B230FT/GT '88 - '91 1.5bar
B28E '82 - '86 1.5bar
B280E '86 - 91 1.5bar
B280F '86 - '91 1.5bar

940.

B200F '91 - '95 1.0bar
B204E '91 - '92 1.5bar
B204GT '91 - '98 1.5bar
B204FT '91 - '94 1.5bar
B200FT '91 - '98 1.5bar
B230FB '91 - '95 1.5bar
B230F '91 - '95 1.5bar
B234F '91 - '92 1.5bar
B230FK '95 - '98 1.5bar
B230GT '91 - '94 1.5bar
B230FT '91 - '98 1.5bar
D24T '91 - '93 1.5bar
D24TIC '91 - '96 1.5bar

960, S90, V90.

B6254FS '95 - '98 1.5bar
B6304FS '91 - '98 1.5bar
B6304FS2 '97 - '98 1.5bar

I hope this helps to clear up what did appear to be bad information.

Bill.

Post by **MadeInJapan** » 11 Jan 2009, 17:40

Thanks Bil...great info!
Do you by chance have the specs on the newer FWD caps? Might be good to post those up too so we'll see how different they are.

EDIT: I may have been premature in posting the warning.
All of the expansion tank caps for FWD/AWD Volvo come up as 1.5 bar. I'm thinking we should take the warning down and only list those cars that need a cap w/ less pressure up w/ a caution...what do you think?