Coolant Flush

[Guest danny_samb]

I have a dohc engine just doing a coolant, flush, I'm running a heater too, how do you bleed the system of air locks

[agent_zed]

Air finds the highest point so you need to have an opening at that point. If your radiator is below the engine this can be hard if you haven't put a bleed valve in anywhere else. You can (carefully) jack your car up and run it for a while so the rad is the highest point allowing the air to come out.

 

Many people (me included) have a house radiator bleed valve. I have a coolant pipe that is quite high on the engine and i have a t-piece into the copper pipe with the valve at the top, higher than anything else. Then i simply fill the rad with the valve open, run up to temp until the water starts to come out and then close the valve off. job done. Just needs a few bits of copper pipe, a t-piece and a valve. all of which will be a couple of pounds.

 

hth

[Guest Bazwaz]

Just a point about coolant. If like me you have an older engine/cooling system you shouldn't use the later pink antifreeze (oat) it can react with any brass/copper or lead solder within the system and you should only use the older blue antifreeze.

 

Baz

[agent_zed]

Eeeek that's what I've had in my engine for the past 5 years!! It said any engine so figured it was ok. Oops might swap that out soon.

Thanks

[Guest Bazwaz]

I'm no expert. I first picked up on it in a Practical Classics mag so did a bit of Googling and found a some more about it.

 

Baz

[IanS]

Talking of pink antifreeze it appears to eat thermostats.

My wifes car ran cold the first winter we had it, temp guage just off the cold end.

I replaced the thermostat and engine temp back to normal and engine management light off.

Ran great through the year until the next winter when the same happened.

I have now replaced the thermostat 4 times in 5 years (waiting for this winter)

Has this happened to anyone else?

 

P.S. this is the first car we had with pink antifreeze