expansion tanks on disco 300tdi's

[Lindsay]

gday
With all this talk of expansion tanks failing I have done 2 things - had a low coolant alarm fitted and bought a new tank, twice. I hear on the forum that the white ones are ok, the black ones not. I returned the first white one I ordered as it had a cracked mounting hole. I just recieved the replacement for it and the seam on it looks dodgy, so I will not put it on. It is a european copy but the quality control on these seems supect. Local landy mechanic has seen 2 of these fail also, both within weeks of fitting. Anyone else heard of probs with these - I am leaning to going genuine-at least you know you'll get 6 to 8 years out of them?? Food for thought. Anyways-I am protected now with the alarm.
cheers
Lindsay

[Lindsay]

Hi
I am hoping that those of you that have had the unfortunate experience of an expansion tank failing could let us know roughly how many kms on the car when it went and what year model??

thanks
Lindsay

[one_iota]

Hi Lindsay,

My Black Tank is still good at 160,000 kms.

I suspect that failures of the original are due to other factors like a head gasket going, overheating and consequential increased pressure...only a hunch. Therefore the tank is blamed (shoot the messenger)

I cooked my donk and after the rebuild the shop put a new cap on the expansion tank...maybe this is the problem...it is supposed to relieve excess pressure...so what if the cap fails...the tank bursts.

What Low level Alarm have you fitted?

[incisor]

i have a black tank at 211,000 and am in the process of fitting the EMS alarm setup you see advertised in the top banners. nice solution as it has extra temp sensor setup as well as float level... and yes i paid money for it as i think the idea is excellent...

[rick130]

I replaced my tank ('98 build, '99 delivery) over twelve months ago (roughly 150,000km) as it was splitting badly below the seam, just wasn't spitting water out yet. I've had no head gasket failures, no hose failures, no overheating in the time of my ownership (110,000km now) to suggest there was any other cause for this splitting.

The 'black tank bad, white tank good' was all over the Pom boards and I questioned it heavily, eg, "it's the same tank without any pigment", "you have other cooling issues", etc, etc, ............until mine split. I bought an OE one, fitted it and joined the chorus.

[incisor]

Originally posted by rick130
and joined the chorus.
brains, looks (look left https://www.aulro.com/afvb/), cooks and he can sing too!

[Coastie]

My black tank developed a leak at the midline join on the drivers side after about 220000 km. Replaced with the new white plastic ones and no problems. I suspected the 15 psi cap may have been building up to a higher pressure but there wasn't a great deal of pressure when hot.

Even when combined with the leaky P gasket the water level never got too low. Had all hoses and radiator replaced after run in with cow several years back.

My father in law would say its built in obsolescence in everything.

Question: If the tank cap psi is so low could the cooling system be run without a cap at all, to stop a pressurised leak if a split happened on a trip?

[rick130]

Originally posted by incisor+--><div class='quotetop'>QUOTE(incisor)</div><div class='quotemain'><!--QuoteBegin-rick130
and joined the chorus.
brains, looks (look left https://www.aulro.com/afvb/), cooks and he can sing too![/b][/quote]

thanks Inc ! us fella's that live here in the hills are a handsome lot, and we pluck a mean Banjo, too. :twisted:

[rick130]

if you do spring a leak on the road (or off) and it can't be repaired instantly, you usually set the cap so that it doesn't pressurise the system. The old style metal radiator caps were set at the first detent so that coolant didn't splirt out everywhere, but it didn't seal and pressurise the system. Not sure how you would do this with the plastic screw caps.

[stevo]

I have fitted the same alarm awhile back mounted mine in the overhead console and extended the wires plus soldered the wires as I do not like those crimp fittings.

the alarm went off on the way to goulburn the water was blown out due to a faulty head gasket

[PhilipA]

Just a comment on the pressure in cooling systems.
My experience in Saudis Heat has suggested that the highest pressure in the cooling system is after the engine is turned off and heat soak sets in.

The major reason for say 15lbs is to stop the system turning to steam around the combustion chambers once the circulation ceases. I doubt whether in a correctly operating cooling system that it gets anywhere near that while the engine is operating and the coolant is circulating.

I remember one day ( probably 40-45c ambient) going to the Nissan dealer in my 1.5 Sunny to get a new exhaust ( which my son broke in half kangaroo hopping while I was teaching him to drive LOL).
I was standing at the parts counter and looked outside to see the Sunny spewing its guts of water. Turned around and said , "and a radiator cap please."
Never had any more trouble.
Regards Philip A

[cookiesa]

Had to run mine without the cap on fully to mine last year. loosen the cap then I taped it with some gaffa tape to stop it vibrating off. Worked a treat.

The pressurisation of the system is to increase the boiling point of the water/coolant in the system. If everything is OK system doesn&#39;t need to be pressurised.

This was due to a pinhole in a house. Under pressure it was spraying with reasonable force, without the pressure it was only trickling down the hose. Let me get to a auto parts shop where I could get another hose. (actually it was a hose part from a holden heater system) I was also concerned that with the force coming out of the hose was it going to split or cause more damage? Figured less pressure on soemthing that has already failed would be better.

(Reminds me, must replace the temporay hose&#33;)

[George130]

You can get low pressure caps. When I bought my defender it turns out the cap on it would pop at 4psi and then bleed down to 1psi. Its the same as the new one I bought but black instead of yellow. Don&#39;t know where to get them though or why they would have done it other than to hide the faults I found once my warranty ha run out.

[51jay]

280,000 no problems yet


bugger&#33;&#33;&#33; I&#39;ve probably just jinxed myself&#33;&#33; why do people ask these loaded questions?? https://www.aulro.com/afvb/

[spudboy]

Can anyone tell me how much the EMS black box costs?

I know I could email the supplier, but I have had only 1 of 4 email enquiries answered by manufacturers in the last month or two. Much quicker here!

Thanks.

Also - what about the price on a Thermoguard? I emailed Ian earlier today but no reply as yet, so would be interested if anyone knows that.

[DEFENDERZOOK]

hey guys......back to the tanks.....

they are made of plastic....they get hot....they get cold.....
again and again.....after a few years they will get brittle....its a characteristic of the plastic.....
nothing is to blame other than age......and wear and tear.....
if you are worried...replace it before it blows...and keep the old one for a spare.....

all plastics will eventually crack.....even the washer bottles go this way....
and they only have cold water in them......its the heat from the engine...
or even just sitting out in the sun.....it will kill them eventually......