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Radiater cap & coolant tank cap

Posted: Mon Jun 23, 2008 7:33 pm
by Bluestreak
Right, so there are two caps in the coolant system one on the radiator and one on the coolant tank.

My one on the coolant tank reads 1.1 on it
The one on the radiator reads .9 on it, is this correct?
Should they be the same? should the one on the radiator have a higher setting. so that the coolant tanks releases first?

Any ideas folks

PS national Bongo meet was great, really good

Re: Radiater cap & coolant tank cap

Posted: Mon Jun 23, 2008 7:51 pm
by bigdaddycain
I can't rememer the actual ratings offhand, but the expansion tank should have the yellow cap, and the radiator needs the red one.... :wink:

Re: Radiater cap & coolant tank cap

Posted: Mon Jun 23, 2008 7:58 pm
by brorabongo
Mine came with 1.1 for both, but when I got a replacement rad, it came with a 0.9. I used it for a while, but was suffering from a leak from the pressure relief pipe under the cap on the new rad. I therefore reused the old 1.1 cap on the new rad, (thank goodness I kept it when I disposed of the old rad!!)

Some say that the rad cap should be of higher value so that, the tank cap will blow first, expelling air? whilst if the rad cap goes it's coolant that is lost straight away. :?


My tank is yellow cap, and rad cap is white with red writing? ( I think :oops: )

Re: Radiater cap & coolant tank cap

Posted: Mon Jun 23, 2008 8:00 pm
by bigdaddycain
Mine had yellows fitted to both up till quite recently...

Re: Radiater cap & coolant tank cap

Posted: Mon Jun 23, 2008 8:09 pm
by Harry
I was losing some coolant from the rad wwith damp spray around the rad top and discoulouration on the pipes plus some pooling of water in the little gutter along the top of the rad..

I had .9 on my rad and 1.1 on my expansion tank.

Having read this and other threads I've swapped them around...and guess what...no more coolant loss :lol:

Makes more sense anyway.

H 8)

Re: Radiater cap & coolant tank cap

Posted: Mon Jun 23, 2008 8:12 pm
by helen&tony
Hi
The higher value on the rad....1.1 on the rad, and 1.0 on the plastic tank...then the lower one will go first, releasing trapped air....if you fit them the other way round, you will lose fluid from the overflow first if you have such a replacement radiator fitted.
Cheers
Helen

Re: Radiater cap & coolant tank cap

Posted: Mon Jun 23, 2008 8:17 pm
by haydn callow
You should have the 1.1 bar cap on the RAD & the 0.9 bar cap on the EXPANSION TANK.. you want the tank cap to blow first in a emergency.. Many Bongo's have 1.1 0n both and this is not really as it should be.
You can even use a plain (non pressure) cap on the rad as long as there is not a outflow spigot just below the cap. Always worth checking after Bongo has been in a garage for any coolant related servicing as it is easy to transpose the caps if you are unaware of the situation.

Re: Radiater cap & coolant tank cap

Posted: Mon Jun 23, 2008 10:45 pm
by Bluestreak
Hi, thanks for the comments, I have changed mine round to .9 on the rad and 1,1 on the coolant tank.I will see how it goes I was checking because I have a small loss of coolant about 10mm in 500 miles.

Hope it sorts it.

Re: Radiater cap & coolant tank cap

Posted: Mon Jun 23, 2008 11:14 pm
by scanner
Bluestreak wrote:Hi, thanks for the comments, I have changed mine round to .9 on the rad and 1,1 on the coolant tank.I will see how it goes I was checking because I have a small loss of coolant about 10mm in 500 miles.

Hope it sorts it.
Isn't that now the wrong way round?

Re: Radiater cap & coolant tank cap

Posted: Tue Jun 24, 2008 12:05 am
by Bluestreak
Yep your right it should be the other way round, and I actually physically did the right way with the Rad at 1.1 and the coolant at .9!