expansion hose

[kevtherev]

hi guys,
travelled down from derbyshire to kent for a long weekend. no probs at all until this morning.....
low coolant light on dash when i started the car, so travelled half a mile to a shop and bought a bottle of water as a temporary measure.
it took a litre to fill it back up. i've only had the car a couple of weeks and did notice i could hear a hissing noise from the expansion cap,
so i went to the pug dealer in maidstone and stuck a new cap on. this hasn't improved things, as when we got back after the 15 mile trip the expansion tank is soaked again and on closer inspection i can see steam coming from the tank area.
i think it could be one of the 2 small pipes coming from the tank.
my question is what is the very small diameter pipe for?? it's right up against the wing then goes to the top of the engine. also could it possibly be the sensor that is located in tank itself. could this come off it's seal at all??
thanks in advance

kev

[Busman]

Just had a look at mine, which COULD be the same as yours. The little pipe in question goes from the expansion tank to the top of the thermostat housing. And isn't the tank end a little bugger to get at? At the tank end, the tiny pipe goes into a bigger 3ish long inch piece of pipe onto the tank. This has a jubilee clip on the tank, and a spring clip on the pipe to pipe joint. It should be a fairly simple job to shorten the tank end by the lenght of the clip and refasten it. I could see how the end of the pipe could perish, and cause a leak.
Worth a try anyway. Not a big expense to do, but very awkward!

Not sure which sensor you mean, but the fluild level sensor is in the expansion tank, you can see the conector on top of the tank.

[kevtherev]

Just had a look at mine, which COULD be the same as yours. The little pipe in question goes from the expansion tank to the top of the thermostat housing. And isn't the tank end a little bugger to get at? At the tank end, the tiny pipe goes into a bigger 3ish long inch piece of pipe onto the tank. This has a jubilee clip on the tank, and a spring clip on the pipe to pipe joint. It should be a fairly simple job to shorten the tank end by the lenght of the clip and refasten it. I could see how the end of the pipe could perish, and cause a leak.
Worth a try anyway. Not a big expense to do, but very awkward!

Not sure which sensor you mean, but the fluild level sensor is in the expansion tank, you can see the conector on top of the tank.

yeah thats the one busman. i'm fairly certain that the steam is coming from the end of that pipe can't see any steam below that level,and the other slightly bigger pipe is cold to touch, but everything is getting soaked now .
and yep it's a pta to get at specially on holiday with ltd kit.
just gonna have to keep topping up and hope it gets me the 160 mile home
thanks for the reply i now know what that pipe is for....

[Busman]

Got all my fingers crossed for you. Tried tightening the clip?

[kevtherev]

Got all my fingers crossed for you. Tried tightening the clip?

yeah tightened it as tight as i could with the tool that me brother had.
same again this morning low coolant light on , but when i opened the expansion cap it let out a loud hiss like it was releasing pressure even though it had been sat overnight and was stone cold.never known a car do that when cold...
i had the coolant changed when i had the waterpump done last week so i've just opened the bleed screws at the bulk head. that was fine, the one at the stat housing was pushing air out tho.
could it be over pressurised somehow?? so it's forcing steam out of this small pipe?

[Busman]

If you've got air at the stat housing, it makes me wonder if the systems been bled properly?

[kevtherev]

If you've got air at the stat housing, it makes me wonder if the systems been bled properly?

funny you should say that. after i bled the stat housing bleed screw dried everything off ,and went 15 mile to maidstone. 70 mph dual carriage way and a bit of town centre driving .
parked up and popped bonnet ........everything is bone dry.no steam,nothing.
come back 4 hrs later topped it up a bit and drove back to me bro's
reservoir is wet again so i'm wondering if i'm over filling it?? and it's being forced out the cap, but to my mind it's not overfilled as you could only just see the coolant.
if its lost all its coolant again overnight i shall take it to a garage in the morning, if everything seems ok i'll just drive it back home and see how it goes.tis a mystery..

[kevtherev]

just a quick update:
made it back from kent so all good there
took it garage yesterday and had it pressure tested and coolant is actually being forced out from underneath the coolant level sensor that is located in the top of the reservoir. the rubber seal must be perished.
seen one on a scrapper so gonna try that first if that don't cure it replace with new from stealers..

regards
kev

[Busman]

Sounds like a good result to me, just a little rubber seal. Well done you.

[kevtherev]

thread resurrection time:

i'm still having the same problem.
i replaced the coolant level sensor with one from a scrapper. still the same . so i replace the o ring. still the same.
i bled it all yesterday as best i could not sure if i done it right as the stuff coming out the rad screw was like one of those posh coffee machines in a resturant (that sort of sound) heater matrix screw ok , no air out the stat screw.
so this morning low coolant light again , so i top it up been for a run , up to 90 on the guage. got home left it an hour and unscrew expansion cap . the level is now almost to the top ,which is higher than what i topped it up to earlier......so
is this air in the system pushing the level up as it cools???
could it be the rad thats full of air?? all pipes to it are red hot
also should there be a rubber seal at the bottom of the threads on the expansion tank??


overall happy with the car just this niggly problem is driving me bonkers!!!