Club 80-90 Forums

Help! I recently bought a t25, took it to Belgium and broke down having cooked the engone as the water pipe had split - so now I am paranoid about damaging my brand new and expensive engine.
Can anyone explain the role of the coolant reservoir? I have spoken to a few t25 owners who have told me that the reservoir should always have water in it between the min and max levels. My garage tell me this isn't so. Every time I put water in this palstic container and go for a run there is no water in it when I get back. But then when my van has stood for a few days and I check the reservoir it is full to brimming and water falls out of it when I take off the cap. The expansion tank is full to the top.

I am well confused and worried about what I should do and whether its safe to run the van without anything in the reservoir or if I should leave the completely full reservoir when this also happens.

You see my dilemma. Can anyone help please?

Many thanks

Amanda

Basicly the header tank which is situated in the engine bay and can only be accessed by removing the large engine cover should be full to the brim when the engine is stone cold to check this properly i'd leave it overnite and check it first thing in the morning, the expansion tank that is behind the rear numberplate flap should be between the max and min mark when engine is stone cold.

Do you get any heat from the blower in the van ? i ask this as you may have air still in the system if it wasnt bled properly when the new engine was fitted

Hi.
The header tank is full to the brim. The reservoir behind the number plate I fill to between the minimum and maximum and when I have been for a run is empty and then when she has stood for a few days is absolutely full to the brim. Howver the header tank is always full! See my dilemma?

Yes i see your dilema but the Haynes bible says to check the levels when they are cold, if the levels are ok when they are cold and your temp gauge is under the red light i'd say that all is well, the missing coolant when the engine is hot is just recirculating the system then returning to the tank as the engine cools tho it may be worth replacing the darlek cap on the header tank as the one way seal may have become weak.

Hey. Thats very reassuring. Will get a new darlek seal (whatever one of those is) and get it fitted. I love my van and am so worried about cooking another engine!!!

Amanda

amandafrost wrote:Hey. Thats very reassuring. Will get a new darlek seal (whatever one of those is) and get it fitted. I love my van and am so worried about cooking another engine!!!

Amanda

all part of the service, just keep an eye on the temp gauge if it stays just below the red light when its up to operating temp then i'd say she's fine, as for the darlek cap click the link sista

http://cgi.ebay.co.uk/VW-CAMPER-TRANSPO ... 2c51864f02" onclick="window.open(this.href);return false;

Where bouts in the country are ya perhaps one of the techs on here is local to ya ?

amandafrost wrote:The reservoir behind the number plate I fill to between the minimum and maximum and when I have been for a run is empty and then when she has stood for a few days is absolutely full to the brim. Howver the header tank is always full! See my dilemma?

Yeah, that doesn't sound right to me. Surely the water level in the expansion tank should be higher when engine is hot (and therefore lower when the engine is cold) because water expands when it is heated and overflows into the expansion tank. Then it gets sucked back into the header tank as everything cools again.

As already advised above, probably worth replacing the dalek cap and see what happens then. Be sure to get a genuine cap though and not the other ones which often fail.
Genuine cap from Brickwerks

Tony

The expansion cap in the engine bay is a one way valve it will allow coolant back to the expansion tank but not to the overflow tank .If your overflow tank is filling up and over flowing the valve is faulty.The expansion tank in the engine bay after the coolent system has been bleed of air should should be full up with coolent.If you are going to replace the cap obtain one from a VW main dealer or the brickwerks as some purchased elseware seem faulty.The garage is wrong about the overflow tank it should be kept topped up between min&max .As in practice in running diesel engines & petrols if there are any small leaks in a not perfect hose connection system on a 25 year old vehicle and any other reason for slight coolent losses the header tank will keep the expansion topped up.Well thats my sixpenny worth of opinion no doubt the proffesionals will advice.

It sounds like you need to bleed the system properly, it's not rocket science and there's full details in the Wiki at the top of the page.

https://club8090.co.uk/wiki/Co ... ing_system

As the coolant in the system expands above a certain pressure it pushes excess coolant through the header tank cap down the hose into the top-up tank. As it cools OR as the pressure drops due to a leak the coolant from the top-up tank is pulled back into the header tank. Thus when you're running you don't get an accurate picture by checking behind the number plate ... unless of course the top-up tank is empty or the red low-level warning light comes on.

Ian.

Wow! Guys thanks so much for the responses. I think I might need to print all of this off and revisit the garage that fitted the new engine! Alternatively if anyone knows of a techi or a good vw water cooled garage in the area please let me know - I live just in the New Forest equi distant between Southamapton and Salisbury.

I just love the vw t25 world!!

Cool.

all part of the service