The Triumph Dolomite Club - Discussion Forum

I have a Clear Dolomite Expansion bottle but i can not quite get it to seal very well.

I would like to do the Mod i think Jon has done by T ing into the bottom radiator hose and a expansion bottle higher up in the engine bay.

What cars do you guys know of that have a Expansion bottle with a Radiator Cap?

Where's the seal problem?

I can hear hissing out of the overflow

If it's hissing out of the overflow this to me would suggest the cap seal is faulty and the system not pressurising properly. Check the condition and type of cap you have and you may find the seal is faulty. A simple and cheap replacement should do the job just make sure you get the right rating cap which escapes me at the moment and depends on the model you have.

SprintMWU773V wrote:If it's hissing out of the overflow this to me would suggest the cap seal is faulty and the system not pressurising properly. Check the condition and type of cap you have and you may find the seal is faulty. A simple and cheap replacement should do the job just make sure you get the right rating cap which escapes me at the moment and depends on the model you have.

Ya its a new cap, its the steel ring inside the bottle that has rusted away.

By the way, there´s expansion header tank for sale in the forum?, brass mine will be beyond repair sooner...

newguy wrote:.....What cars do you guys know of that have a Expansion bottle with a Radiator Cap?

There's a Stag one on eBay just now, they're transparent and they hold twice as much but no use for connecting in circuit since they only have the same stub as the Dolomite one, but at the bottom of the bottle instead of near the top.
No reason that one of these shouldn't work though.

Hans from Holland who races Sprints and posts on here has said that he has had trouble finding bottles that seal well.
I choose a modern one cos it works much much better than the stock item, mine is a VW one and has the pressure cap built in. I got fed up with track temperatures well over 1/2 on the gauge. When you come off the track the temp is still very high and if you are unlucky you get an air block in the top of the engine.
I have had no problems since fitting the VW bottle.............errrrr not with temperature anyway

trackerjack wrote:Hans from Holland who races Sprints and posts on here has said that he has had trouble finding bottles that seal well.
I choose a modern one cos it works much much better than the stock item, mine is a VW one and has the pressure cap built in. I got fed up with track temperatures well over 1/2 on the gauge. When you come off the track the temp is still very high and if you are unlucky you get an air block in the top of the engine.
I have had no problems since fitting the VW bottle.............errrrr not with temperature anyway

What Vw Model is the Tank off?
Thats what i want
Can you show me a few pics Jon

Yer tis Stew
Its off a Golf but dunno which one, I just raid my local scrappy

that looks like a generic VW/ Audi/Seat expansion bottle, plenty of them around in our scrap yards.

We use brass Range Rover bottles on our race car. They have a larger capacity than a Dolly item. We fit the bottles on the firewall to get them as high as possible (no washer bottle of heater fitted). The new car has had the bottle modified with an outlet near the bottom which feeds to a tee piece in the lower radiator hose.



Not a good photo of the bottle but might give you some ideas.

Mark

Thanks Mart This is what i have decided on doing.


Alrighty well last week i got hold of alot of scrap dealers, alot of them did not have any VW parts, Finally i found a company that only has VW, Audi, Pug parts.
And i found the bits i wanted like Trackerjack Specd to me.

I am going to be using a Header Tank of a VW VR6 Same as Passats, Golfs etc. Some models anyhow.
And i am also using the T Link off it aswell.

As the cooling system at the moment has a expansion hose going from the top Thermostat Cover to the Header tank, then the over flow hose going to atmosphere.

Looking at modern Cooling systems, After (Jon told me) the Bottle i have now has the bottom hose which always has fluid goes to the bottom of the radiator, and the top hose from the bottle goes to the Top thermostat cover or Hose.

So i am going to be doing the same thing, I am using the T link to go into the bottom Radiator Hose to the Bottom of the Header Tank, and the top hose into the thermostat cover. I am also going to mount the Header Tank on the Firewall so it is nice and high.

Also for the first time this weekend i left the car at after a boot back to pick up my bag and when i came back to the car the expansion tank had let go and was letting coolant out of the Header Tank, bloody thing wasn't sealing the car was only a little bit warmer than normal.
I just got in and got driving i drove for about 5minutes and the temperature had hardly changed.
I stopped popped the bonnet and it had suck all of the coolant out of the tank, i was guessing i had a airlock.
I took the cap off and there was not alot of pressure at all. Topped it up with water and kept driving, it started to cool down a bit but still wasn't happy.
So i when i got to where i was going i popped the bonnet again and the water had gone down more again, so i topped it up to where it usually sits and left it over night.
In the morning i took the Thermostat filler cap out and there was air there, so i topped the water up and was mint on the way home.

Carn't wait to get a good condition Header tank in. With summer here cooling is everything with these cars as most of you know.
I will let you guys know the difference it makes if any, hopefully it keeps the water supply replenished and airlocks out of the system.

Header Tank



T Link & Cap

Picked up some hosing, brass reducers, Hose Clips.

The hose guys here that i deal with have been pretty good to me.
Giving me trade less 45% which makes it pretty handy.

Have decided on a place for the Header Tank, and i will route the hose back behind the motor and under the carb's to keep it all nice and low.

coming along nicely, personally the feed back to the lower hose is the key because I think that the car when used on track (hammered) causes cavitating in the pump and airlocks can form (sometimes).
These are just guesses on my part.

Is that an 1850 servo I spot?