Bongo Fury

Hello, just been watching your detailed video about bleeding the water system, as I'm having troubles of my own at the moment. The filler cap actually on the rad, seemed to be like a blank type, where mine is a pressure type with spring. Is my bongo cap wrong??
Thanks
Simon
Maidstone Kent

Just to let you know, video part 1,
3 mins. ( you tube)

Not sure about the pressure spring thing but looking at my Bongo both caps are 1.1 bar but the one on the radiator has a RED top and the one on the filler bottle has a YELLOW top. One of the experts will be along soon to explain it all to you.


Tony

That sounds like my setup.Phew, With both caps being pressure caps, where as the one on the video looks like a non pressure ( blanking) type of cap.
Thanks.

The one on the rad should not have a spring on it. The header tank is the only one that needs to have the pressure relief valve on.

to be honest it doesnt matter whats on the rad, or what pressure it blows off at, because it is only sealing at the top seal, and doesnt blow, cause its got nowhere to blow to. so that bit isnt used when fitted here.
all the venting/blowing should be done at the expansion cap/vent.
no harm having two venting caps at all, as long as your rad hasnt got a vent pipe next to the rad cap.

Northern Bongolow wrote:to be honest it doesnt matter whats on the rad, or what pressure it blows off at, because it is only sealing at the top seal, and doesnt blow, cause its got nowhere to blow to. so that bit isnt used when fitted here.
all the venting/blowing should be done at the expansion cap/vent.
no harm having two venting caps at all, as long as your rad hasnt got a vent pipe next to the rad cap.

Agree..................But............... .............Playing Devils Advocate................ As the Bongo doesn't have an expansion tank just a degassing tank that copes with expansion until an expansion tank is needed (rated pressure on rad cap).
Now, if a dedicated expansion tank was fitted would it matter if a vent pipe from the rad communicated from it too?
And instead of dumping coolant the tank would do what a real expansion tank does, sucks it back in, nuff said...

would such a tank need to be at lower pressure than the main system, and then be above the system pressure to force it back again.

the coolant does expand a little (20mm) when its hot.

Northern Bongolow wrote:would such a tank need to be at lower pressure than the main system, and then be above the system pressure to force it back again.

the coolant does expand a little (20mm) when its hot.

Site is playing up again...........Tank needs to be open to atmospheric pressure, as the system cools the negative pressure in the system sucks the coolant back in or it would collapse with the external 14.7psi that we have pressing on us all.

Interesting, I would like to think that the cap on the rad would be a slightly higher pressure than the de-gassing tank because, otherwise water would be released( as water is always touching the underside of the cap). Where as, in the tank the water is an inch or two below the cap and would release only air and not water. That's if indeed if the rad cap has anywhere to vent/escape to.

That's if indeed if the rad cap has anywhere to vent/escape to.

That's the key point - Bongo radiators don't have the outlet to allow a vent cap to work - the seat may lift, but there is nowhere for the water to go. The top seal is the seal at teh end of the day, and it doesn't move.

Some pattern radiators do have a vent outlet on the radiator though, and these must be blocked if used in a Bongo.

simon638 wrote:Hello, just been watching your detailed video about bleeding the water system, as I'm having troubles of my own at the moment. The filler cap actually on the rad, seemed to be like a blank type, where mine is a pressure type with spring. Is my bongo cap wrong??Thanks
Simon
Maidstone Kent

Hi Simon,
Your cap is not wrong,the two caps are the same type(or should be).

Cheers.

According to the diagram on LushProjects, both caps have the same part number:

http://lushprojects.com/bongopartsmk2/c ... mgno=.html

Mine definitely had red sticker on the rad cap and a yellow one for the expansion tank. Does anyone else have this combination?

the yellow ones are gen mazda, the other colours--red, black, usually come with aftermarket rads, or are bought seperately.
you can fit anything to the rad top as long as it fits the top seal correctly, it can be no vent, or 0.9 or 1.1 any colour.
the main thing is fit a gen mazda yellow 1.1 to the exp tank, as this is both the safety valve, and the pressure reducing/cooling vent into the system. so for me a gen everytime.
i made a cap testing gadget and over half i tested failed in one way or another.
when cooling/cooled the system drops to 1 pound neg pressure, if the exp cap is faulty it will try to suck air into the system by any other meens it can.