not happy

[bongomadness]

I started a post about steam coming from under my hood............spigot under rad cap spurting water etc etc I was advised to put hose on spigot and blank off!!!!!..............................Mechanic came and found I had 0.9bar rad cap that had failed.the whole system has been flushed through and refilled and air pushed out and new rad cap with 1.1 rating.All is now well but mechanic disagreed with the comments as if there is no spiggot and the water boils where is that pressure going to blow to?????? If pipe is blanked off the whole system is pressurised but then surley the rad cap with the right bar is to keep the system pressurised.
Any thoughts on this

[rita]

I started a post about steam coming from under my hood............spigot under rad cap spurting water etc etc I was advised to put hose on spigot and blank off!!!!!..............................Mechanic came and found I had 0.9bar rad cap that had failed.the whole system has been flushed through and refilled and air pushed out and new rad cap with 1.1 rating.All is now well but mechanic disagreed with the comments as if there is no spiggot and the water boils where is that pressure going to blow to?????? If pipe is blanked off the whole system is pressurised but then surley the rad cap with the right bar is to keep the system pressurised.
Any thoughts on this

Hi,
Is the cap that you refer to on the radiator or the expansion tank.

If the said cap is on the expansion tank,the overflow pipe should NOT be blanked off

Cheers..

[bongomadness]

Hi,
Is the cap that you refer to on the radiator or the expansion tank.

If the said cap is on the expansion tank,the overflow pipe should NOT be blanked off

Cheers..

Hi Rita the cap is the one on the rad that i am talking about which has little spiggot pipe underneath it.My expansion tank overflow is not blanked off. I am just curious as to why my mechanic who has worked on countless numbers of bongos does not agree with the replies i got back.
Jayne

[M 80NGO]

Nothing should be blanked off, if it was then it would have came from the factory like that, the cap blanks off the overflow until the pressure exceeds the caps swl then it will let coolant pass via the overflow, i suspect that at some time a previous owner lost the origional cap and just replaced it with a mazda item not realising that they actually have different load indexes, it could also be that the cap was the origional but had become weak over time, the main thing is that its all sorted now.

[rita]

Hi,
Is the cap that you refer to on the radiator or the expansion tank.

If the said cap is on the expansion tank,the overflow pipe should NOT be blanked off

Cheers..

Hi Rita the cap is the one on the rad that i am talking about which has little spiggot pipe underneath it.My expansion tank overflow is not blanked off. I am just curious as to why my mechanic who has worked on countless numbers of bongos does not agree with the replies i got back.
Jayne

Hi,
If the radiator has a pipe on the neck under the cap it is not the original mazda type radiator.The original radiators did not have a prv cap,just a plain one.The pressure release is at the expansion tank cap.

Cheers

[bongomadness]

Nothing should be blanked off, if it was then it would have came from the factory like that, the cap blanks off the overflow until the pressure exceeds the caps swl then it will let coolant pass via the overflow, i suspect that at some time a previous owner lost the origional cap and just replaced it with a mazda item not realising that they actually have different load indexes, it could also be that the cap was the origional but had become weak over time, the main thing is that its all sorted now.

My thoughts entirely ..............thanks

[Northern Bongolow]

please ,please, blank off the rad vent pipe,the only place it should vent is above the coolant level in the expansion tank.

[francophile1947]

Nothing should be blanked off, if it was then it would have came from the factory like that, the cap blanks off the overflow until the pressure exceeds the caps swl then it will let coolant pass via the overflow, i suspect that at some time a previous owner lost the origional cap and just replaced it with a mazda item not realising that they actually have different load indexes, it could also be that the cap was the origional but had become weak over time, the main thing is that its all sorted now.

My thoughts entirely ..............thanks

The above is totally wrong, also your mechanic is talking out of his rear end The original Mazda radiator does NOT have an overflow pipe and pressure is released via the pressure cap on the "expansion" tank

[bongomadness]

The above is totally wrong, also your mechanic is talking out of his rear end The original Mazda radiator does NOT have an overflow pipe and pressure is released via the pressure cap on the "expansion" tank

Can i just say that i believe my radiator is not an original mazda one,and common sense tells me that pressure is released via the expansion bottle cap,also comments are gratefully recieved but i think it unfair to say my mechanic is talking out of his "rear end" when maybe not all information was fully digested. How many people on this forum are trusted bongo experts?????I am sure not everyone on here.A forum is to collect information,give information and exchange ideas,organise events trips etc.Although i take in everyones suggestions to slate off a mechanic who has a high knowledge of the vehicle and specialises in all diesel and petrol cars that you do not know is dammed right rude to say the least..Are you qualified to tell me how to repair my van francophile???

[francophile1947]

Are you qualified to tell me how to repair my van francophile???

Enough to know that you're mechanic is wrong in this case I was merely trying to ensure that you didn't end up with a set-up having 2 ways for the pressure to be released - a situation that your mechanic will probably have never seen. I worked in the motor industry for several years and never came across one.

[Northern Bongolow]

this area of the coolant system is usually misunderstood .
this reaction just shows the level of passion we have for our bongo.s.
all i wish to do is stress that this pipe,must be fixed correctly,or the result could be very serious.
unfortunately your mechanic is very wrong.as seen many times on here,trying hard does not always mean a good fix,euther by outside trusted mechanics,or indeed by us on here.

[waycar8]

The after market rad that you have is different from the mazda standard, as mentioned already it doesnt have the pipe in the neck of the rad where the rad cap is. The after market ones come with a 0.9 bar cap, which isnt strong enough as the bongo cooling system presurises more than 0.9 bar, hence the reason why the mazda one has a 1.1 bar.

When coolants lost from anywhere below the expansion tank air gets in so if the pipes blanked off no air can get in, thats why it has an expansion tank with a presure release cap so it will lift on there and not on the rad. As your rad cap now will lift when your system is presurised and because its got the pipe on the neck it will seep out and air will get in If your mechanic new this then he would probably agree with us.

Speaking from experience, I drove around with the new after market rad on for a while and it weeped coolant out of the pipe in the neck untill I blanked it off, and had to blled the system again and quite a few people who have bought the after market one has had the same problem. I will say this thoe if you leave the pipe open you will overheat again, did you tell your mechanic that the origional mazda rad doesnt have the pipe?

[bongomadness]

The after market rad that you have is different from the mazda standard, as mentioned already it doesnt have the pipe in the neck of the rad where the rad cap is. The after market ones come with a 0.9 bar cap, which isnt strong enough as the bongo cooling system presurises more than 0.9 bar, hence the reason why the mazda one has a 1.1 bar.

When coolants lost from anywhere below the expansion tank air gets in so if the pipes blanked off no air can get in, thats why it has an expansion tank with a presure release cap so it will lift on there and not on the rad. As your rad cap now will lift when your system is presurised and because its got the pipe on the neck it will seep out and air will get in If your mechanic new this then he would probably agree with us.

Speaking from experience, I drove around with the new after market rad on for a while and it weeped coolant out of the pipe in the neck untill I blanked it off, and had to blled the system again and quite a few people who have bought the after market one has had the same problem. I will say this thoe if you leave the pipe open you will overheat again, did you tell your mechanic that the origional mazda rad doesnt have the pipe?

Thanks Waycar for the explanation................and sorry to all concerned if i sounded a bit hassled (have had a bad weekend although that is no excuse but i think it best to show you all a picture of the now set up of my rad in the van . . . .will get on the case tomorrow and show you how it is now

[jumper]

If the rad has a breather pipe with a 1.1bar cap and the expansion tank has a breather pipe with a .9bar cap then where is the problem? the expansion cap tank will always blow 1st, and if for some reason the expansion tank fails then the rad becomes the only release of pressure before the countless hoses take the strain.
I have the opinion that if something has a pressuse release then dont modify or adapt it, even if it was not part of the original component specification

Ian

[Northern Bongolow]

when a bongo leaves the production line it has a rad with no vent pipe,and a fixed cap with no pressure relief escape on it at all.the only pressure relief is on the expansion tank 1.1bar,
the 0.9 caps come from the standard nissan micras and most other jap cars.the problems start when ill informed people put non standard things,be it rads or caps onto a system they maybe dont understand.
the bongo system when either working very hard or is slightly faulty(blocked rad,faulty stat)operates at approx 0.9 bar or even above, that is why the cap pressure is set above normal average cars range,ie 1.1bar.a healthy bongo diesel 2.5 usually runs at around 0.7/0.8 when working well.
hope this helps to clear this one up.