bleeding the cooling system

[methodwares]

I have just replaced the hoses with the lovely silicon and the rusty pipes with stainless ones from ACT; looks much prettier now. The front of the car is still in the air. I filled the radiator and the header tank a few times as it slowly bled down. After the tank didn't loose any more, I started the car and let it run for a bit, filling the tank as I went down. I also opened and shut the bleed valves every so often to get the air out. It got to a point where opening the valves only water came out, I was happy. I turned the car off and opened them one last time just to make sure, left side was fine, the right side chucked out the steam like a whistle on an old steam engine. It eventually calmed down and I went through the process again, but it never really seemed to get rid of it all.

Will this be the case or do I need to persist? Or have I done it wrong?

The temperature never got above 91 on the laptop.

Thanks for any help.

[Ireland]

Persist.

I have always found the RHS a pig to get all the air out of it as well.

[JensenA]

Bleed it when the Engine is Warm(ish) not when hot and under pressure. And not when the engine is running.
Park the car so the nose is in the air - eg front wheels on a plank of wood.
Undo the Expansion tank cap.
Undo the big nut on the passenger side of the Radiator, and use a funnel to top it up with water.
Loosen off bleed nuts until water comes out. Tighten them back up.
Top up through the radiator again (if required).
Tighten everything back up, and run the engine for about a minute, and repeat. That should do it.

[methodwares]

JensenA said:

Bleed it when the Engine is Warm(ish) not when hot and under pressure. And not when the engine is running.
Park the car so the nose is in the air - eg front wheels on a plank of wood.
Undo the Expansion tank cap.
Undo the big nut on the passenger side of the Radiator, and use a funnel to top it up with water.
Loosen off bleed nuts until water comes out. Tighten them back up.
Top up through the radiator again (if required).
Tighten everything back up, and run the engine for about a minute, and repeat. That should do it.

Pretty much what I did. The front is on jack stands. I'm wondering if its even possible to ever get all the air out of the system as the water in the expansion tank never seems to want to bleed down much as its not that much higher than the bleed valves and such a small amount compared to the radiator itself, but the radiator is much lower than the bleed valves that it couldn't fill any part of the system above it. Is it worth using a system pressure tester to do this? -- pressurise the system, open the valves, close and repeat, refilling as necessary?

[JensenA]

I've never had problems bleeding the system on mine. With the nose in the air, the radiator 'bleed' nut is the highest point of the cooling system - ignore the expansion tank - and then the engine warm, but cooled down sufficiently so there is no pressure in the system. I've used the radiator for topping up and bleeding. I'd say just drive the car and see what happens, keeping an eye on the temp guage to see if anything untoward happens. Maybe you are worrying a bit too much. It's a nice sunny day, get out and drive it

[cerdad]

Have you tried replacing the cap on the expansion tank, mine kept spitting its dummy and that cured it,i was told it should be replaced every 2 years ( mk 2 golf ).

[Tanguero]

You need to make sure that you run the engine long enough for the thermostat to open otherwise you can get air trapped all over the place.

[methodwares]

JensenA said:

I've never had problems bleeding the system on mine. With the nose in the air, the radiator 'bleed' nut is the highest point of the cooling system - ignore the expansion tank - and then the engine warm, but cooled down sufficiently so there is no pressure in the system. I've used the radiator for topping up and bleeding. I'd say just drive the car and see what happens, keeping an eye on the temp guage to see if anything untoward happens. Maybe you are worrying a bit too much. It's a nice sunny day, get out and drive it

Sunny!? Where? I had another go, sort of. When I went back to it yesterday afternoon, the header tank had bled down so I re-filled it. I opened the radiator and the two bleed valves and it quickly leaked water out of all three. Happy enough, tightened them back up and ran it for a bit. All seemed well.

Its all back together now... had the exhaust off as well to get welded. Hopefully I can get it out tonight.

As a side note, it's amazing how much smoother it runs when you don't have a b**gered t-pot.