Cooling question

[jamesandtheopenroad]

Okay. So the level in the main cooling tank steadily goes down over time and I keep having to top it up. The level in the expansion tank stays the same. I though it might be the dalek cap and hose to the expansion, so both have been replaced. Can't see a leak anywhere but I can't understand why the pressure isn't pulling the coolant back through when the system cools. Any ideas?

[Ian Hulley]

New dalek cap from ... ?

Ian

[jamesandtheopenroad]

Brickwerks, chap. One of the non-VW but as good as, ones. Hose from there too.

[AdrianC]

Okay. So the level in the main cooling tank steadily goes down over time and I keep having to top it up. The level in the expansion tank stays the same. I though it might be the dalek cap and hose to the expansion, so both have been replaced. Can't see a leak anywhere

There must be one somewhere, for the coolant to be escaping.

but I can't understand why the pressure isn't pulling the coolant back through when the system cools. Any ideas?

...because, instead, air is being sucked in through whatever leak your coolant's going out through. Path of least resistance, an' all.

Step 1 - find and eliminate leak.

[leroiandjayne]

i have similar problem,had a main pipe fastner give up and lost a lot of coolant,then coolant light flashing intermittently,found leak on pipe between expansion and top up tank the level of which doesnt seem to change,light came on again today,checked it and had to put about a mug full into expansion tank,top up tank unchanged,could it be faulty dalek cap as i can actually suck air out of it but not back in?.temp always is fine it rarely goes much above white mark on gauge anyway, help!!

[itchyfeet]

A small leak can be very hard to find especially if its on the engine where it just evaporates
White deposits indicate this sort of leak
I have also seen leaks that seal up when hot and open up again when cool so go looking when cold also. I discovered this because I could drive 10 miles or 200 miles and loose the same amount of coolant

How much do you lose over what time/ mileage

[Ian Hulley]

Our similar leak was a drip from the join where the radiator hose met the front to back plastic pipe, it was only an occasional drip and didn't disrupt the feed to from the header tank.

Ian

[leroiandjayne]

AHA found the little bugger! it was where the lower pipe fits on to the secondary water-pump and i only spotted it by chance,i could see moisture around the lip of the pipe so had a little tinker with the clip thats supposed to hold it on whilst she were running and squirted it did!!!!,so cleaned it up and added an extra jubilee clip and also replaced the dalek cap and now have some circulation especially when i squeezed main pipe a few times i spotted the air bubbles coming through at last, oh joy is me.

[itchyfeet]

Its taken me 6 years to get mine to stop being a waterleaker the final piece was a new rad this year
I suspect the joy won't last long

[leroiandjayne]

my first was 5 years ago on way back from 1st ever camperjam,was amazed how many vw zoomed past us whilst stuck on the side of the A5!!! it was again around the clip on main pipe into engine on the cylinder head,it had actually cut into it ever so slightly then when she got warm it blasted out,it had steadily been getting worse for a good while before that,indicator was little dirtyish spots appearing all over the backend after a journey,funny how we learn so about these buses eh! usually the hard way i think ha ha cheers