radiator/heater bleeding?

Question

how do i bleed the heater/radiator the reason i ask i had a new
radiator fitted and the temp gauge never rises over a quarter of the way up it is a fiat brava diesel thank you.

Answer 1

Take the radiator cap off, and start your engine. As it starts to heat up, you will see air bubles on top of the rad. keep water handy to top up as the water level drops. keep on running engine and check temperature gauge. When all air bubles have gone, it should be okay.

Answer 2

Turn the heater temperature control to maximum HOT. Don't bother about switching on the blower.

Identify the output hose from your heater matrix. It will be the one about 1/2 inch in diameter that goes towards the bottom of the radiator. It may not actually be atached directly to the radiator so look closely. Disconnect it and hold it so that the open end is a little below the height of the radiator filler cap. Shove a cork or something that won't crumble into the exposed metal spigot.

Fill the radiator with coolant (water+anti-freeze) until it pours out of the hose. Put your finger over the end and then mate the hose back to its spigot (remove the stopper first).

When it's all reconnected run the engine with the radiator cap off until it's all warmed up. You may see the level drop slightly as the thermostat opens and remaining air bubbles out.

When you're happy top up to the level mark, replace the cap and drive on.

Use the heater as a guide rather than the temperature gauge. If the heater is not providing hot air when you turn on the blower then you still have an air lock or blockage somewhere and a power flush may be the answer.
Note that the heater must work properly. If it doesn't then there could be a serious circulation problem whatever the gauge says so you must get the system checked.

Answer 3

I wouldn't worry if it's only getting a quarter of the way up the scale. It may appear that it is running hotter than before, but that could be due to the radiator being a cheaper non-genuine item. They usually tend to be thinner and therefore have less cooling surface area.

However, if it does start to overheat, then read on..

I doubt it's the thermostat, unless by pure coincedence, it has failed at the same time as the rad. It sounds like an air lock in the system which could be rectified (as said previously) by letting the engine cool, filling with water and leaving the cap off while starting the engine and letting run for a while. You should hopefully see the level of water drop due to bubbles of air being expelled into the expansion tank. Some cars are a lot more difficult than others, and some have bleed screws. Be sure to scan all the coolant pipes for one or more bleed screws situated (usually) on the pipes themselves. If you undo these while filling the system, it should also help an awful lot. Hope this helps, and best of luck. Marc.

Answer 4

Start with cold engine and open radiator cap. Add coolant until the radiator is full. Since the top of the radiator is higher than the engine, any trapped air should bleed off when the thermostat opens. Once the coolant level rises in the radiator, put on the cap.

Answer 5

Air inside. All you need to do is bleed out the air. There is a valve at the top of every radiator which needs a special key to open. You can buy them from DIY stores. Open the valve slowly until you hear the air coming out, wait until a little water dribbles out and close. Takes less than a minute each one. Usually it is only the upstairs radiators that get air in them as it rises to the highest point. Best of luck.

Answer 6

It sounds to me like the new radiator is doing it's job. I wouldn't worry about it unless it over heats.

Answer 7

one consideration is the thermostat .. if all else is installed properly then the thermostat will modulate the temp ...

Answer 8

sorry but i dont know. if you go on google and type in bleed raditor or something to do with it there shoud be a page with instructions how to do it on there

Answer 9

replace thermostat