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expansion tank cap!
Posted: Fri Jun 15, 2012 1:16 pm
by stefan442
Bit of a nightmare,the cap popped off my expansion tank when I pulled over some coolant came out! I stopped straight away and got recovered to a garage. He was going to tow me until I pointed out the 4wd and he put the bongo on top. Nice bloke.
Anyway, at the garage all they had and could source was 0.9 prv cap. I read on here it needs to be a 1.1 prv cap. Will the bongo be OK for the drive home next week or should I try and get a 1.1bar cap delivered out to France? I am driving back next Friday and Im trying to.keep the driving to a minimum. They topped up the coolant in the garage and it was a couple of litres. It was an hour drive from the garage to my campsite and everything was fine, and at no point has the temperature reading gone above anything it has ever been.
I'm wondering if I didn't put the cap on properly after doing my pre drive checks. Wouldn't fail any other way would it?
Cheers.
Stefan
Re: expansion tank cap!
Posted: Fri Jun 15, 2012 1:41 pm
by Northern Bongolow
the cap should require push down and turn to release it, if this is worn, it could in theory work itself off, check the kneck of the expansion tank.
i would bleed the system if you have lost 2 ltrs, just to be safe, any probs may not show until it gets hot, then its too late.
the 0.9 may work, but i wouldnt use it, what cap is fitted to the rad top, as this may be a 1.1 (swap it if its a sprung 1.1, and put the 0.9 on the rad top, as this sprung bit is not used/needed on the rad top as it only acts on the top seal.
if your stuck pm me your address and i will post you one if that helps.
the system could in theory get up to 0.9 bar if its hot and working hard/loaded heavy etc best to fit a 1.1
Re: expansion tank cap!
Posted: Fri Jun 15, 2012 1:49 pm
by stefan442
The one on the road is 1.1, I know because I made sure the coolant was topped up enough that it was coming out the top of the radiator. I could bleed it and work out any trapped air. Will have to make the missus watch the YouTube vids

I'll look online and I'll pop to the local garage and see what they say.
I'll check at the expansion tank as soon as I get back to the poor old girl. Thanks.
Re: expansion tank cap!
Posted: Fri Jun 15, 2012 4:30 pm
by Ian
Do you want me to send you one? I have genuine Mazda ones (recommended) or Blueprint copies (slightly cheaper). I can express it over to you in 2 working days, and you can pay for it when you get back. Email me if you want to go ahead
[email protected].
Re: expansion tank cap!
Posted: Fri Jun 15, 2012 6:00 pm
by stefan442
Would have taken you up on that, i quickly eBay'd one though.
Should have looked in the shop
http://www.ebay.co.uk/itm/Radiator-cap- ... _512wt_952
Hopefully will get here in time.
Thanks for the help

Re: expansion tank cap!
Posted: Sat Jun 16, 2012 9:33 pm
by chipvan
Defo bleed it before you use it again, or it could be a costly mistake
Re: expansion tank cap!
Posted: Sat Jun 16, 2012 9:52 pm
by stefan442
Would it be OK just to do it with water, I can do the first bit OK. Just worried about doing the second bit with the missus. Will.probably end up with a shouting match!
Re: expansion tank cap!
Posted: Sat Jun 23, 2012 11:45 pm
by stefan442
Made it back. No problems, going to drink some of my duty free beer and get a good nights sleep and worry about unpacking tomorrow!
Will give The bongo a good looking over though. 2400 miles and I think she deserves a clean and an inspection!
Re: expansion tank cap!
Posted: Sun Jun 24, 2012 12:03 am
by Velocette
Just a thought, if you have an unmodified temperature gauge the temperature could rise considerably without it changing position. It is damped to read the same from 75C to 100C or so, can't remember the exact number.
better to fit a digital temp alarm or do the mod on the guage.
Re: expansion tank cap!
Posted: Sun Jun 24, 2012 1:09 am
by stefan442
oh. Well thanks, master of bubble bursting!
Re: expansion tank cap!
Posted: Mon Jun 25, 2012 9:32 pm
by Northern Bongolow