Rover Coolant Fill Up Question

[Speedy Gonzales]

I have a question regarding the cooling system on my Rover 4.6 V8. My cobra is currently having a new gearbox fitted but once I have it back I am planning on dressing up the engine a bit, one of the jobs is to tackle the coolant system. I have all the necessary silicone replacement coolant hoses and once my car is ready im going to have a bash at draining the system, fitting the new hoses and then refilling it again and after reading quite a few horror stories on here regarding air locks and such like im terrified of cocking it up so does anyone have any practicle advice on re-filling the system without getting any air locks in it.

[Clive]

Best way to fill the system is through the highest point, usualy the heater. Remove the heter hose at the thermostat or where it enters the block and making sure the heater is set to hot, place a small funnel into the hose and fill slowly until the coolant comes out of the block where you disconnected the hose from. Reconnect the hose and top up the header tank. Restart the engine after checking all the hose connectors for leaks. Keeping a careful eye on the temp guage and checking the fans come on at the correct temp. If the engine starts to overheat/make knocking noises switch off immediately and allow to cool before removing the filler cap and checking levels. If all is well then after the engine is cool recheck levels anyway.
Hope this helps,
Clive

[maxGD059]

Just try to avoid having any high points without some method of bleeding. You will be able to 'force' some of the air out by just squeezing the bottom hose in any case.

I fitted a bleed valve into the heater pipe to aid bleeding & if I remove the header tank & support it a few inches higher & open the bleed valve then I can get virtually all the air out in minutes.

[Speedy Gonzales]

The top hose from my radiator has a cap placed within it just before it goes into the block. Would this be ok to fill the entire system from. Ive included a pic to make it a little clearer, thats if ive attached it correctly.

[markieboy]

Looks okay to me, thtas how I did mine with no problems.

Just remember to tighten your silcone hoses after they have got them hot once or twice but not to tight as you will cut into them.

Regards

Markieboy

[Speedy Gonzales]

Thanks for that, you have put my mind at ease. How will i know when i have enough in. Is it basicallly until the top hose is full?

[maxGD059]

It'll be a doddle with the rad cap that high in the engine bay. Because you have a bypass on the stat cover then by squeezing the bottom hose you should be able to 'burp' through most of the air. Any residual will then come through when you start it up. WRT overfilling, you can't as it will just pour out! Just put in the same amount as came out when you drain the system

[Sidecarbod]

I found that it is best to run the engine with the cap removed as this allows the air in the hoses to be pushed round the system by the pump and water to the point where it gets to the filler neck, at which point it can escape. You just need to keep an eye on the level as the motor warms up and be ready to top it up as the coolant level drops.

I found that my system took on board at least another 1.5 litres as it warmed up.

[Speedy Gonzales]

Ive read somewhere before on this forum about squeezing the bottom hose, i just needed reminding of it, thanks for that.