Draining The Radiator

[knowlson]

Right at the weekend I need to drain the radiator so I can fit some new things to the car :D :D Any tips on the best way to do it?

[knowlson]

Ok so no one has done this before then??

[yannick]

Ok so no one has done this before then??

Sorry Knowls,

I was waiting until other had had a chance to reply first, because while I have done it several times I couldn't think of anything special to say.

I followed the Haynes manual instructions and everything went fine. Lots of dirty water on the garage floor and a bit of a flush of the system before sealing it completely up.

Anyone else got any more precise comments?

[knowlson]

Ok so no one has done this before then??   

Sorry Knowls,

I was waiting until other had had a chance to reply first, because while I have done it several times I couldn't think of anything special to say.

I followed the Haynes manual instructions and everything went fine. Lots of dirty water on the garage floor and a bit of a flush of the system before sealing it completely up.

Anyone else got any more precise comments?

Cheers matey just wanted to check if there was anything specific I should watch out for

It should be fine just make a bit of a mess in the garage but it will be worth it with all my new silicone pipes fitted

[yannick]

Cheers matey just wanted to check if there was anything specific I should watch out for

No probs. I always get surprised by just how much water there is in the system... and I've always ended up getting my sleeves soaked

I've done it 3 times now; twice to change an engine & once to change the radiator (in the street that time). It's always been a messy job :P

[ae111sr]

Andy, sorry to be a bit late with this but been away from a PC all day.

Here's my experience of the job. Did mine a couple of weeks ago When I changed the crap Halfords thermostat for a proper Toyota one. When I put the Halfords one in I replaced all the coolant with nice new red stuff from Mr T so I didn't want to lose it. This is the way I did it.

Don't do this when engine is hot.

Jacked front of car up and put it on axle stands.

Removed the bolts holding the front of the drivers side plastic undertray so that I could get at the radiator drain tap.

Attached small bore flexible tube to drain tap and put other end in suitable container (I used the original plastic can that the coolant came out of). Unscrewed the drain tap (I had to lever an intercooler pipe out of the way to do this) and waited for the coolant to start to drain.

Removed radiator cap to let air in the top to help flow out the bottom.

When the flow stoped placed a suitable tray (I used a large cat litter tray) under the gearbox directly below where the bottom hose goes into the thermostat housing.

Removed the bottom hose from the thermostat housing and tried to direct any coolant from the hose into the tray.

I changed the thermostat here (Toyota part number 90916-03090). Undid the two bolts and removed the top of the housing - removed the old thermostat and replace with the new one, not forgetting the new rubber seal. Replaced the top of the housing and the bolts.

This should help to stop most of the coolant getting to the floor. One other thing I did was place a sheet of cardboard under the drip tray in case there was any stray coolant.

When it comes to refilling make sure the heater control is in the fully open position before you start to refill. Replace any hose connections that you have removed and shut the drain tap on the rad then gently pour your coolant into the rad until it's full. Start the engine and leave it to idle until it gets warm. Keep topping up the radiator as the coolant level drops. Eventually the thermostat will open and allow coolant to circulate round the complete system - keep topping up the coolant. When the fan cuts in you know that the system has reached it's peak temp and you can then shut off the engine. Check the rad coolant level and replace the cap. Top up the overflow bottle and keep a check on it for the next couple of days and I found that the level dropped several times over the following week.

By the way – when I put the Halfords stat in I found that the coolant that drained was very badly discoloured and I threw it away. I flushed the system by putting a garden hose in the top red hose and leaving it run (the water exiting from the empty thermostat housing) until the water ran clear. If the weather had not been so cold I would have run the car for a day or two with plain water in the system just to flush it completely before refilling with coolant.

Looking forward to seeing the silicone hoses when the jobs done – I might just be temped as well. :P

[ae111sr]

Just another thought for you - you might need to change the hose clamps as well. The wall thickness of the silicone hoses will probably be different from the Toyota jobs - I had to get new clips for some of the vacuum hoses I've replaced for that reason.

[knowlson]

Cheers john that that sort of write up I was after

[ae111sr]

Here to help - hope it goes well. Lets see some pics of the new hoses

[doggy]

ae111sr-smashing write-up on the coolant change, i used it myself this weekend to do my 98 ae111. Here's a few thoughts on my experience:

I changed the thermostat here (Toyota part number 90916-03090). Undid the two bolts and removed the top of the housing - removed the old thermostat and replace with the new one, not forgetting the new rubber seal. Replaced the top of the housing and the bolts.

I didn't bother with that bit meself as the lads in Toyota said i should be fine with just the coolant.

When the fan cuts in you know that the system has reached it's peak temp and you can then shut off the engine.

I thought this point would never come, the engine was idling for a good 15 mins before i advanced the process by cracking open the throttle, nearly poisoning myself and my neighbour.

Once concern i have is that there's no separate bleed for the engine block, i'm slightly worried in case there's air trapped in there. also there's no bleed screws for bleeding air when refilling. any thoughts?

[urotsukidoji_badassdemon]

Isn't there a drain pluggy thingamajiggy at the bottom of the rad? Usually plastic too, so be careful when turning it. Or just undo the jubilee clip of the bottom hose and pull the hose off, and take the expansion tank cap off too.

[doggy]

Yeah there is, but should there not be a separate one for the block. when the engine is cool and you're doing this job, the stat is closed, so any fluid inside the block stays there until it opens next, which is when you've finished filling the system after a flush. it's a chicken and egg situation. mmmm chicken