Changing coolant on a Volvo 2020

[Quandary]

I have been trying to do this all morning so in desperation am seeking some tips.
The engine is in a Moody S31, the coolant drain is on the side of the block to which there is only access over the top, it is immediately in front of the oil filter, the dip stick tube has been carefully located in line with it about 2cms in front and the fuel pump is just above. It is not a help that the heater duct is just on top here. The drain cock has two fragile looking pins for turning it but I can not find any way of applying any torque, I have tried various small spanners, open ended on the lugs and rings over them but there is not enough room to move it. There must be a device to grip this thing? I tried making a tool by drilling a hole in a bit of hardwood and burning slots for the two lugs with an angle grinder but because the locked position of the pins is about 45 degrees it jams against the oil filter before it can turn.
Someone must do this and know the secret or is there some where I could suck the coolant out with a Pela?

 

[black mercury]

I think there is a pipe going from bottom of water pump to bottom of heat exchanger. You could disconnect this at the pump. It will leave a small quantity in the block, but if you are only replacing the coolant and don't have any contamination you want rid of, it won't make a huge difference.

 

[Quandary]

Thanks, will have a look at that.
I might try using the smallest ratchet from my socket set, sacrificing a socket by grinding a slot across the sides, I need to do this every second year, I had the engine out last winter but my attention was focused on the saildrive, worth having a good think about what else needs doing when there is opportunity.

 

[Quandary]

So I got the drain cock undone, in the end I got anough leverage with a tiny (5mm) ring spanner over one side of the roll pin, unfortunately no coolant emerged and the bore was coated with black stuff which looked uncomfortably like sealant. Not much skin left on my knuckles.
My latest plan is to disconnect the two coolant pipes from the calorifier and drain it there, would have been easier to do that in the first place as I have to get in there to look at why the release valve is discharging so much water. Can I put a hose to the caloifier feed or return and flush the engine from here provided I regulate the pressure, doing it that way might save me some skin and blood, though access to the calorifier through the cockpit locker involves septagunerian gymnastics almost as bad as the engine.
Before I do anything I am going to rewrite my winter list with a bit of planning for combining tasks.

 

[JohnGC]

I've just done this today. I don't have a tap and I don't think it worth fitting one because there has always been enough crud accumulated inside the drain hole to stop the coolant flowing out.

This thread contains some useful advice.
http://www.ybw.com/forums/showthread.php?467537-MD2020D-Removed-coolant-drain-plug-no-water

John.

 

[JohnGC]

If you search, you should also find advice/opinion on using the same type of coolant. The VP dealer here in Plymouth also advised me that I shouldn't change to a different type. But like everything else, you can find contrary advice on the internet!

 

[peteK]

I have the earlier Perkins version with the same tap are you aware that the tap unsrews as when I tried to drain mine no coolant came out and had to unsrew the tap and poke around with wire.Mines also in a hard to reach place and have to use a mirror to find it.

 

[Quandary]

Having read the other thread (Thanks for the link John GC) I will have another go with a longer probe, after running it with the Wynns rad flush. I have 5 litres of the pre oat type antifreeze, enough to replace the coolant and put some through the raw water side as I finish. I am reluctant to touch the heat exchanger on the 'leave well alone' or 'if it aint broke' principle.

 

[Daydream believer]

When I drain my 2020 there is a plug with a square tapered end on it. I believe that Halfords sell a fitting for a fiver to fit this. But not wishing to blow £ 5 for a one (or just a few) off, I undo this by reversing a half inch socket, which, fortunately, fits & putting an extension bar in the other side (select the correct size, of course) & release it with that.
Seems to work Ok & saves a fiver.