Draining the Anti-freeze.

[Searay45DB]

This sounded easy enough, but when I opened the drain in the block to drain the anti-freeze, nothing came out. Figure the thermostat was shut. I presseraurizes the system till it started draining. Now I am wondering if I messed up thermostat by doing this. Thoughts?

Thanks

 

[leonz]

This sounded easy enough, but when I opened the drain in the block to drain the anti-freeze, nothing came out. Figure the thermostat was shut. I pressurized the system until it started draining. Now I am wondering if I messed up thermostat by doing this. Thoughts?

Thanks

Was the engine cold when you did this?
Did you remove the radiator cap prior to opening the block drain?, if not, with the thermostat shut it would be a closed sealed system when cold.

I would remove the thermostat to be sure it is not stuck open with debris or if the spring is jammed.

 

[OrangeRidge]

Only air-locks and "solids" contamination are of concern
in this system . The thermostat is a heat responsive valve , so
as long as there's no solid stuck in it ,there should be no problem .
I don't open block plugs ( welch plugs ) since it's the cause of most
head failures ( air trapped ) after radiator fluid replacement.
The volume in the block is not too much of the total fluid volume .

 

[Searay45DB]

I had to take some antifreeze out again after I filled it. I can't get the new block heater after tightening, I can still wiggle it and am afraid of blowing it out. But when I opened the drain cock this time, it drained perfect. Engine was warm. If there was dirt in the water jacket, it's gone now. Any idea on the block heater?

Thanks

 

[Searay45DB]

Only air-locks and "solids" contamination are of concern
in this system . The thermostat is a heat responsive valve , so
as long as there's no solid stuck in it ,there should be no problem .
I don't open block plugs ( welch plugs ) since it's the cause of most
head failures ( air trapped ) after radiator fluid replacement.
The volume in the block is not too much of the total fluid volume .

You just brought up an interesting question since I drained from the plug, do I need to bleed it?

 

[OrangeRidge]

If you have not opened an engine-block welch plug during
your fluid draining procedure , then don't do so . The fluid in the
radiator , two rubber pipes and the coolant expansion bottle
is enough volume . These are very small systems and could
economically be done every year really.
If a welch plug has been opened , then removing the thermostat
and flushing water through the plug hole with a hosepipe , until
there's no bubbles ,is the only sure way I know of removing air.
Hold the thermostate housing with one hand and the hose with
your other , so that your ready to press it down ( air-tight then)
the moment your happy , and whilst the hose is still running.
NO fluid will then be lost from the plug hole if air can't get in
the top.