Replacing Thermo/Bleeding the Coolant help

Re: Replacing Thermo/Bleeding the Coolant help (robk)

Sat, 21 May 2016 22:07:34 GMT

Regarding the bleeding of the cooling system, I just wanted to point out something important that no one else ever seems to mention.
Most of us will know that the heater control needs to be set to maximum, and this is always mentioned in how-to guides, BUT in some SW20s (mine included) the heater valve is electronically controlled by a servo motor. This means that you can't just move the heater control slider to full hot with the car turned off. The ignition needs to be on so the servo motor has power to open the heater valve.

Re: Replacing Thermo/Bleeding the Coolant help (Flighter)

Sat, 09 Jan 2016 23:04:11 GMT

Reddtarga

Five year change intervals??
My owner's handbook says one year or 20k

That's what it says on the (aftermarket product) bottle. I'm fine with that, as I figure the chemistry has come a long way since my MR2 was built. I used to use some weird red Toyota corrosion inhibitor additive (closer to when the car was new), which came in 250ml bottles and is long since discontinued, and even that was to be replaced every two years.

Re: Replacing Thermo/Bleeding the Coolant help (Hoonsy)

Sat, 09 Jan 2016 21:07:00 GMT

Don't wanna drain all the coolant completely, feel like I'll do something wrong. So just a top up/bleed air out will do me haha

Thanks for the help fellas. Fingers crossed I do it without any drama :)

Re: Replacing Thermo/Bleeding the Coolant help (Reddtarga)

Sat, 09 Jan 2016 14:55:27 GMT

+1
Also tell them what car you have.
But make sure you get the 'Toyota Red concentrate' that comes in 4 liter containers (that will make up 8 liters of mix).

Don't get the 'Toyota pink long life pre-mixed', as I mentioned previously.

How many containers you need will depend on whether you only want it for top ups, or whether you want to do a full coolant change.

Re: Replacing Thermo/Bleeding the Coolant help (Peter)

Sat, 09 Jan 2016 14:54:20 GMT

Hi Hoonsy,
Yes you do just go to your Toyota Dealer Spares Dept & ask for red coolant.

Re: Replacing Thermo/Bleeding the Coolant help (mr2y)

Sat, 09 Jan 2016 00:54:35 GMT

Getting concentrate is a really good tip if it's true the older engines don't have a drain plug on the engine, that way you can flush it with water, then calculate how much water is still stuck in there and add the concentrate.

Re: Replacing Thermo/Bleeding the Coolant help (Hoonsy)

Sat, 09 Jan 2016 00:20:46 GMT

Aight, so I'll pick up some Toyota concentrate soon then. Do you just purchase it from the dealerships? And if so, do I literally ask for "Toyota red coolant"? Never done this before

Re: Replacing Thermo/Bleeding the Coolant help (mr2y)

Fri, 08 Jan 2016 21:20:50 GMT

That's why I'm confused. Toyota recommends their red mix, but doesn't it all come down to Japan having a law against silicates in coolant?

Edit: apparently Japan also has silicate free green so that may not mean anything then

Re: Replacing Thermo/Bleeding the Coolant help (TomsMR2)

Fri, 08 Jan 2016 21:20:02 GMT

Toyota 50/50

Re: Replacing Thermo/Bleeding the Coolant help (Hoonsy)

Fri, 08 Jan 2016 21:02:42 GMT

Reddtarga
Hoonsy
Had a look and my mechanic used a red coolant. Is it safe to assume he used a 50/50 mix as well? Or in other words, if I use a 50/50 mix to top it up, will it have any negative consequences if his mix was slightly different?

For topping up a different mix shouldn't matter much.
If you are worried about it why not ask your mechanic what mix and brand he used.

Considering it was a year ago, I doubt he'd remember. Could be worth a shot however..
If I intend on picking up the red coolant, is there a recommended brand/mix that everyone here uses?

Re: Replacing Thermo/Bleeding the Coolant help (Reddtarga)

Fri, 08 Jan 2016 19:24:46 GMT

Flighter
If I remember correctly, red isn't safe with brass or copper components (e.g. some radiator tanks for instance). I ended up selecting green coolant as it works with everything, although at the expense of a slightly more frequent replacement schedule (5 years instead of 6).

FWIW, here's what my Toyota dealer told me:
Toyota Red is fine for your early MR2 with copper/soldered radiators/pipes, and has a better formulation than the green stuff.

But don't get it mixed up with the Toyota Pink pre-mix that is designed for aluminum radiators that are used in later models.
Toyota Pink has a completely different organic acid in it than in Toyota Red.
The organic acid in Toyota Pink will damage brass/copper/solder heater cores in 1995 and earlier Toyotas.

Five year change intervals??
My owner's handbook says one year or 20k

Re: Replacing Thermo/Bleeding the Coolant help (TomsMR2)

Fri, 08 Jan 2016 16:55:42 GMT

Strange as the recommended coolant is Toyota long life red and all the heater lines including the core are brass

Re: Replacing Thermo/Bleeding the Coolant help (Flighter)

Fri, 08 Jan 2016 16:29:55 GMT

If I remember correctly, red isn't safe with brass or copper components (e.g. some radiator tanks for instance). I ended up selecting green coolant as it works with everything, although at the expense of a slightly more frequent replacement schedule (5 years instead of 6).

Re: Replacing Thermo/Bleeding the Coolant help (Reddtarga)

Fri, 08 Jan 2016 12:22:04 GMT

Hoonsy
Had a look and my mechanic used a red coolant. Is it safe to assume he used a 50/50 mix as well? Or in other words, if I use a 50/50 mix to top it up, will it have any negative consequences if his mix was slightly different?

For topping up a different mix shouldn't matter much.
If you are worried about it why not ask your mechanic what mix and brand he used.

Re: Replacing Thermo/Bleeding the Coolant help (Hoonsy)

Thu, 07 Jan 2016 17:35:36 GMT

Had a look and my mechanic used a red coolant. Is it safe to assume he used a 50/50 mix as well? Or in other words, if I use a 50/50 mix to top it up, will it have any negative consequences if his mix was slightly different?