Block drains on later cars

[Stag About Town]

My car is a 1977 Auto and I am about to change the coolant. According to the Haynes manual, later cars don't have block drain taps and you just need to disconnect the bottom hose. Before I crawl around searching for plugs or taps, can anyone please advise.

Many thanks

John

[Robmsharp]

My 1976 Mk2 doesn't have a block drain tap. Hope it helps!

[Tdm]

Mine too is a '77 Auto and has no block tap.
To drain the coolant I disconnect the bottom hose.

[Lingen]

John.
Undoing the bottom hose will drain the radiator and the block/heads, down to the level of the water pump. That will still leave some coolant in the lower part of the block, which can only be drained by removing the screwed in plug under each exhaust manifold. That is a dirty job! However, disconnecting the bottom hose will let out enough to add 3.5 litres of new antifreeze, and top up with water, to achieve the recommended mixture.
Mike.

[andybaulf]

Two ¾" AF (19 mm) flat head screw either side of the 'V' have to be removed to drain as much old coolant as possible, you might have to poke out accumulated grunge with a wire if it doesn't flow. The off side screw is a bit of a bugger to get at. A socket, universal knuckle and an extension bar is my method, the near side is much easier. It's a good idea to flush out the whole system with a garden hose, feed through the top hose to the rad with the bottom hose removed, feed through the top of the bottom hose (at the pump suction) to flush out the block. Make sure that you open the heater valve (put lever to hot) before you start. I hope this helps

[DJT]

I changed the coolant on mine a week or so back and cleaned up the brass plugs whilst they were out. These photos show the locations.

image.jpgimage.jpg

[Greengiant]

I have this to do and photos are a great help.
Is it best to put the front of the car up onto ramps?

Martin

[DJT]

I have this to do and photos are a great help.
Is it best to put the front of the car up onto ramps?

Martin

Yes, you will need to raise the car somehow.

[Stag About Town]

Thanks one and all. Great advice as usual.

John

[022Dave]

I changed the coolant on mine a week or so back and cleaned up the brass plugs whilst they were out. These photos show the locations.

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When I first removed mine to flush the system, no water came out! I used a bent wire coat hanger to get the crud out, but as Mike said, it's a dirty job, as the murky water suddenly rushes up your arm!

Dave

[72BLUE]

When you put the brass plugs/bolts back in, I believe they should have a fibre washer on to seal against the block.

Cheers
Keith.

[davidf]

When you put the brass plugs/bolts back in, I believe they should have a fibre washer on to seal against the block.

Cheers
Keith.

They should have a fibre washer, but I find a dowty seal is better.

[mjheathcote]

You shouldn't really get any sludge or crap coming out the plugs to be honest, not if you have correct antifreeze/anti-corrosion in the system.

[aerosilver]

I did this job a couple of weeks ago as I had the old yellow antifreeze which you can't get now so had to do a thorough flush with the hose and then refill with the blue stuff. My recommendation is wear good eye protection when undoing the block drain plugs. This protected my eyes but I still got a good glycol shampoo!

Bob
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[DJT]

What I would add to this is to be very careful with draining anti-freeze as some is poisonous to animals. The way I do it is to siphon as much as possible out of the radiator filler bung (please don't start another discussion about the dangers of siphoning, they are well known and if using clear hose are avoidable) then refill with water. Run the engine to mix the coolant, siphon and repeat. Do this a few times to dilute the antifreeze so that any spillage from the block drains is less likely to attract animals and can be rinsed away easily.
As much as I don't like the neighbour's cats, I would hate to be responsible for poisoning them......