YOU REALLY NEED 2 PEOPLE TO DO THIS

1. Unscrew the Coolant Tank cap and unclip the strap holding it to the side of the inner wing and lift it up as high as you can get it with all the pipes attached.
2. On the top hose there is a plastic screw in the top of it. Get someone to stand by this and undo this.
3. Now with you standing holding the Coolant tank over the top of the wing and another person holding the srcrew from the top hose put your mouth over the top of the coolant tank making it air tight blow holding in the pressure and not letting go. Keep the pressure on until you see out of the screw hole pure coolant flowing out with no air in it. While the coolant is flowing out air free get the person to screw in the plastic screw back in all the time you are holding in the pressure. Once the screw is back in you can remove your mouth from the coolant tank.
4. Now you need to follow the same procedure for the screw on the top of the the pipe coming from the top of the water pump and remove any air from this side of the cooling system.
Once you have done the same for the water pump pipe screw you can put the coolant tank back in place and screw on the cap. Hopefully your Cooling system should be free from any air locks.

Also on a regular basis leave the car running and wait for the Cooling Fan to cut in while watching the temperature gauge and make sure that it cuts in where it normally does. If it starts to go above the 2 3rd's line then switch the car off and investigate what the cause is before driving the car. Likely causes are air in the cooling system, blocked radiator or cracked radiator, faulty water pump, faulty thermostat, a hole in one of the water pipes, faulty fan switch or incorect coolant mixture.

Do not let the car overheat
Never let the car overheat or let it get into the danger zone where the little red light on the temperature gauge comes on. If your in traffic and the car goes above the normal temperature where the fan cuts in pull over and switch the engine off. Call someone out and have the car towed home or to a garage and investigate the problem before driving it again.

Turbo Failure
Because the turbocharger on a Renault 5 Turbo is a small T2 Garrett it spins up quickly, partly the reason 5 Turbo's are so quick, but this also means that they really are on the go all the time that is why the life expectantcy of the Turbo is roughly about a year. But there are a few things that you can do to prolong your Turbo's life.

1. Change the oil regularly (Maximum every 6000 miles/Recommended every 3000 miles). Because your engine oil is what lubricates the bearings inside your Turbocharger and if the quality of your oil is poor this is going to have an effect on these bearings, thus causing them to seize up (New Turbo Time NOT CHEAP £250 Recon + Fitting). So the rule is change your oil as often as possible and use a high quality Engine Oil Semi-Synthetic minimum.

2. Also you can prolong the life of your Turbocharger by getting in the habit of every time you finish your journey and want to switch off your engine, let the engine idle for about 2 minutes then switch off the engine. This allows the Turbo to stop spinning before the oil supply to the Turbocharger is cut off by you switching off the engine.

Another Factor that will make your Turbo's life shorter is by turning up the Boost (Meaning the Turbo spins at a higher RPM that normal thus wearing it out quicker).

A Dump valve may improve the life expectantcy of your Turbo though this may only be true of hybrid Turbo's running higher Boost im not sure. Any way the dump valve releases the pressure left in the the inlet pipe when you release the throttle, otherwise this pressure causes the Turbo to stall and when you apply the throttle again it has to spin up from start again causing Turbo lag. Where as if you release the pressure via a Dump Valve the Turbo keeps spinning and picks up speed again when you apply the throttle after gear change. It doesn't neccessarily make the car quicker or make the cars BHP figure any greater but maybe give the Turbo a bit of extra life.

Fitting a dump valve guide

Worn Clutches
Worn clutches are a big problem for the 5, because they're a common problem and they are not cheap to replace. The reason being because these cars accelerate so quickly it puts alot of stress on the clutch. So having an uprated clutch will be a better bet than the standard renault clutch especially if you are running higher Boost. To have the job done properly you are looking at around £400. That is with the engine being removed. You can do the job the same way as with other cars by just removing the gearbox but because of the limited space chances are that it will not be alligned properly so probably won't last very long. So to make your clutch last here are a few tips.

1. Do not ride the clutch as this will cause it to wear.

2. Try not to rest your foot on the clutch pedal as this could stretch the clutch cable or wear the thrust bearing.

3. Sudden accelaration from a standing start all the time will wear your clutch so if your game is traffic light grand prix's then your probably best off having an uprated clutch.

Rule of thumb with the GT Turbo
This is where having a deep pocket comes into it. If something goes wrong with a 5 Turbo try to fix it as soon as possible because before you know it you'll have another problem then you'll find it hard to get back on top of them. Bottom line is treat them like a baby as they can be very temperamental cars when not treated right !