Airlock in 1.6 K Series

[Fastinmydreams]

I've tried searching Tecktalk on the club site and via Google, but I can't find the information that I know is out there.  I have replaced the coolant in my 1.6 K series (no heater), but now have an airlock.  How do I clear it?  Engine temp rising beyond normal, yet no hot water in return hose to base of rad and electric fan not kicking in.  All fine previously.  As I have no heater, I naively thought that I wouldn't have a problem.

[Jonathan Kay]

A recent summary of the hierarchy of methods.

Jonathan

PS: How I found that.

[Roadsport06]

Method A - Bleed tee.

Here

This goes in your highest hose and slowly fill from there so you don't get air locks. Once at the correct level close up the bleed tee, massage the bottom rad hose with a few big squeezes, run the car up to temperature so the thermostat has opened, let it cool and check if you need to add a little at the bleed tee so that hose is full of coolant.

Some people seem to struggle more than others with air locks. I never have but I fitted the tee during my build.

[Silver Machine]

One of the recommended solutions is drilling the thermostat. Before I drilled the thermostat my 1997 k series I regularly had air locks when changing coolant. Since I drilled the stat refilling is far easier and I don't seem to get any air locks. 

[Wrightpayne]

There is lots in the archives - I've posted in several threads on the matter.

Its just finding the right key words to use as the search criteria in google - not ideal I know! 
 

Quick summary - drilled t-stat, raise front of car, top rad bung removed (old copper cored rad) fill via heater hose bleed tee using funnel until coolant overflows at rad bung, bung back in, lower car, keep filling at bleed tee till full and put cap on, top up header tank to level. Fill slowly - unavoidable with a bleed tee!!

Heater valve open throughout (if you have one) and squeeze the bottom rad hose vigorously a few times at various stages of the filling process to encourage coolant to settle / air locks to move.

[Geoff Brown]

Having owned two K Series one with & one without a heater all I used to do was open the heater (if required), remove the bleed plug on the nearside top of the rad & allow the system to eject the air/coolant as it became warm before carefully replacing the plug.  

Do not forget the suitably positioned drip tray & plenty of mopping cloth.

[Fastinmydreams]

Thanks for the responses guys.  I've got some leads to follow there when I can get back to the car.  

I read online that the cooling system has a capacity of 5 litres, but can only get 2.5 litres in or out.  If it is 5 litres, how do I get it all out?

The highest point of the cooling system on my car, which has no heater, is the top hose.  I assume that the bleed T would be place in one of the smaller diameter hoses.  Not sure if this would help.

[Wrightpayne]

It should still have a loop from the T-stat housing around the back of the engine to the water rail above the exhaust. Estimate 15/16mm bore heater hose. This is where you fit the bleed tee in the absence of a heater.

[Jonathan Kay]

"The highest point of the cooling system on my car, which has no heater, is the top hose.  I assume that the bleed T would be place in one of the smaller diameter hoses.  Not sure if this would help."

It needs to be at the highest point. Some Sevens seem to need it, others don't. I'd approach this as an experiment: keep working up through the hierarchy of methods until you find what works for yours.

Jonathan

Edited: Crossed with Ian's.

[Jonathan Kay]

"I read online that the cooling system has a capacity of 5 litres, but can only get 2.5 litres in or out.  If it is 5 litres, how do I get it all out?"

I don't think that I've seen this discussed recently, but by removing the thermostat.

Jonathan

[Fastinmydreams]

Thanks to all of you for your advice and leads.  The problem is sorted.  I left to car with the nose raised overnight with the header tank top loosened.  This afternoon I removed the top rad bung and ran the engine.  The thermostat opened, the fan triggered and the temperature stabilised.  Topped up system and replaced bung.  Whatever the problem was, it has now sorted itself out and I celebrated with a blat around my favourite local circuit.

I assumed that the 'missing two litres must be in the block, so I doubled the concentration of the replacement coolant on the basis that it would be further diluted once poured into the system.

Thanks again!

[Jonathan Kay]

Well done. Thanks for adding the solution.

Jonathan