0.9bar radiator cap

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nfn

0.9bar radiator cap

Post by nfn » Tue Sep 07, 2010 1:33 pm

Just changed the radiator and stat out and bled the system yesterday. Drove it today and everything seems fine and leak-free. But I have this niggling doubt about the radiator cap on the new radiator (from the Mazdabongoshop), which says 0.9 on it. The old one was rated at 1.1bar. Is it worth switching back to the old cap? and can it be done without bleeding the system again? My inclination is just to leave it.
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Re: 0.9bar radiator cap

Post by francophile1947 » Tue Sep 07, 2010 3:28 pm

Definitely change it. The system is designed to run at 1.1 bar, so you could lose your coolant because the cap opens too easily. If you leave the header tank cap on, you should be able to replace the radiator cap without much coolant loss or air getting in :D
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nfn

Re: 0.9bar radiator cap

Post by nfn » Tue Sep 07, 2010 4:04 pm

Thanks Francophile. I notice that in this post
http://www.igmaynard.co.uk/bongo/forum/ ... 1012166eac
the cooling system pressure approaches 0.9bar when the fans cut in.
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Re: 0.9bar radiator cap

Post by mikexgough » Tue Sep 07, 2010 5:31 pm

Just took a look see at mine......I used the same supplier for my Radiator....and it's a 1.1 bar on the radiator
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Re: 0.9bar radiator cap

Post by dandywarhol » Tue Sep 07, 2010 9:28 pm

The radiator should have a plain, non pressure cap and a 1.1 cap on the expansion tank. Most Bongos leave Japan with a pressure cap fitted to the radiator cos they're easier to get hold of IMO
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Re: 0.9bar radiator cap

Post by mikexgough » Thu Sep 09, 2010 8:11 am

dandywarhol wrote:The radiator should have a plain, non pressure cap and a 1.1 cap on the expansion tank. Most Bongos leave Japan with a pressure cap fitted to the radiator cos they're easier to get hold of IMO
My rad cap is plain (should have made that clearer - damn engineering brain thinks everyone is keeping up :oops: ) and rated to the 1.1 bar.......the header tank is 1.1 bar pressure cap..... :wink:
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Re: 0.9bar radiator cap

Post by rita » Thu Sep 09, 2010 10:58 am

Hi,

I was thinking,if the radiator does not have a leak off pipe(over flow) fitted,does it really matter what pressure of cap is used as it will only act as a plain cap,??

Cheers.
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Re: 0.9bar radiator cap

Post by Northern Bongolow » Thu Sep 09, 2010 12:03 pm

rita wrote:Hi,

I was thinking,if the radiator does not have a leak off pipe(over flow) fitted,does it really matter what pressure of cap is used as it will only act as a plain cap,??

Cheers.
spot on there sir. plus if you have a sprung cap on each tank/rad,you always have a spare
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Re: 0.9bar radiator cap

Post by Donnie » Tue Aug 18, 2020 4:17 pm

Right sorry to bring up a decade old topic :shock: :shock: :shock: :shock:
but, I've just replaced my radiator too and have the same 0.9 vs original 1.1 bar cap issue.

So, reading whats on this thread so far, are we saying it doesn't matter that the radiator cap is 0.9bar? We seem to be saying it will act like a stopper on there anyway? So, say pressure gets to 1.0bar nothing will happen?

Sorry for what's probably daft but just wanted peace of mind :-)
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Re: 0.9bar radiator cap

Post by g8dhe » Tue Aug 18, 2020 6:02 pm

No check your radiator for a overflow pipe from the mounting for the cap. If it has an overflow pipe that is open then you need a 1.1bar cap fitted, if it is sealed or there is no overflow pipe then it won't matter what cap is fitted.
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Re: 0.9bar radiator cap

Post by Donnie » Tue Aug 18, 2020 6:23 pm

Cant see an overflow pipe for either the old one or the new one so I guess Im good to go:-)
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