Draining the coolant on a Corolla AE92

[NightFlight]

Hi,

Need to change the coolant on my 1991 Corolla (4AFE engine).

(The images go from right to left, 4 to 1)

The Owner's manual isn't much help locating the radiator and engine drain plugs - see Image 4 from the manual.

I cannot see anything on the near side of the radiator remotely like in the Manual's drawing. Ditto for the driver's side.

In image 3 is a top down photo of the Near Side of the radiator. Is that round cylinder the top of a release system?

In Image 2 is a photo from below up, with the bottom of that cylinder just visible and an open pipe visible at the bottom of the photo. Is this it?

As for the Engine drain plug, I can't see anything remotely like in the drawing on the driver's side of the engine block - see photo 1.

Changing the coolant is such a common thing, these plugs must be fairly accessible.

Edited February 21, 2010 by NightFlight

[Blind Kid Seeks]

in the 2nd pic... thats the drain hole... the white plastic connected to that hole.. on the other side of the splash guard is the Tap... turn it... and your coolant should leak out.

if your still struggling... just pull the bottom radiator hose off.

[CHA54]

the block drain port is hidden underneath the cast iron brackets bolted to the block, it's right next to the oil pressure light switch.

[NightFlight]

the block drain port is hidden underneath the cast iron brackets bolted to the block, it's right next to the oil pressure light switch.

Accessible only from beneath the car I take it.

Sounds like it needs jacks.

[CHA54]

not really, it's basically impossible to get at with the engine assembled.

[NightFlight]

not really, it's basically impossible to get at with the engine assembled.

Engine disassembled???

The handbook goes on as if draining & replacing the coolant is just one of those things any owner can do every 20,000km or once a year.

It has as steps 5 & 6 in the procedure as 5. Open radiator drain plug. 6 Open engine drain plug.

But I don't think I'm really up to disassembling the engine right now... <_<

Does the engine side of the coolant system need to be drained for a coolant change, or can I get away with just draining from the radiator spigot & then flushing?

Maybe the manual was aimed at a different engine model or something, though it's the right handbook for the car.

Edited February 23, 2010 by NightFlight

[NightFlight]

in the 2nd pic... thats the drain hole... the white plastic connected to that hole.. on the other side of the splash guard is the Tap... turn it... and your coolant should leak out.

if your still struggling... just pull the bottom radiator hose off.

Yes I can see the white plastic tap. Looks like the splash guard will need come off to access it.

Is this a security feature or did they make access simpler in later models?

[trdrolla1]

in the 2nd pic... thats the drain hole... the white plastic connected to that hole.. on the other side of the splash guard is the Tap... turn it... and your coolant should leak out.

if your still struggling... just pull the bottom radiator hose off.

Yes I can see the white plastic tap. Looks like the splash guard will need come off to access it.

Is this a security feature or did they make access simpler in later models?

Its really quite simple mate, just take off the splach guard, or even just a few screws to be able to bend the front down, and turn on the tap. Im guessing its behind the guard for protection against an outside forces/objects accidently coming in contact with and switching on your tap draining your coolant..

[CHA54]

if you've got this many concerns over just draining the coolant, I'd suggest taking it to a mechanic to have it flushed.

Draining the coolants the easy part, getting the air out of the system after re-filling is more involved.

[NightFlight]

I'm just really looking for an answer to the steps involved in changing the coolant in this model.

not really, it's basically impossible to get at with the engine assembled.

Engine disassembled???

The handbook goes on as if draining & replacing the coolant is just one of those things any owner can do every 20,000km or once a year.

It has as steps 5 & 6 in the procedure as 5. Open radiator drain plug. 6 Open engine drain plug.

But I don't think I'm really up to disassembling the engine right now... <_<

Does the engine side of the coolant system need to be drained for a coolant change, or can I get away with just draining from the radiator spigot & then flushing?

Maybe the manual was aimed at a different engine model or something, though it's the right handbook for the car.

[CHA54]

Here's how to do it...

-Set the heater to HOT inside the cabin

-Jack car up as high as you can and put it on chassis stands

-remove passenger side splash tray to gain access to drain ***** and lower radiator hose

-get a large bucket to collect the old coolant

-place bucket under drain port and undo drain *****, once it starts draining undo the radiator cap to increase the flow rate

-it's a LOT faster to remove the spring clamp from the lower radiator hose and pull the hose off the radiator

-once the coolant is drained, reconnect the lower radiator hose, do up the drain ***** and fill the system with plain water and a radiator flushing agent if you wish.

-Run the car until it's hot and thermostat opens, you will notice this by the change in temperature of the radiator hoses. You can wait until the thermofan comes on.

-Let it run for 10 minutes then switch off, let it cool down a bit if you want and drain the fluid out again

-I like to remove one of the heater hoses and use a hose to flush the old coolant out of the heater core too, but some people have difficulty removing the heater lines.

-While the coolants out, replace the thermostat and thermostat gaskets with new genuine toyota parts.

-Connect everything back up, and fill the system with genuine toyota long life coolant via the radiator fill port.

-I mix the toyota concentrate coolant slightly weaker than 50/50 with distilled water (available at supercheap, autobarn, repco etc in 5L bottles)

-Once the radiator is full and wont take anymore coolant, you need to get the air out of the rest of the system.

-Grab a 2L softdrink bottle, cut the base off it and wrap the pouring end in electrical tape until it's a tight press fit in the radiator fill port.

-Clamp the overflow bottle line from the radiator so fluid can't pass through it, then push the softdrink bottle into the radiator ready for the burping process.

-with the car still on stands with the front elevated as high as possible, start the engine and filll the modified soft drink bottle with coolant so it's a few centimeters above the radiator.

-Let the engine get up to operating temp so the thermostat opens, keep topping up the bottle as air comes out and the level goes down.

-Squeezing the radiator hoses helps to push the air out of the system when it's hot.

-Make sure you keep your hands/arms/clothes away from the thermofan in case they switch on while you're messing with the lower radiator hose to get the air out.

-Once no more bubbles come out of the system, remove the bottle and install the radiator cap.

Dont forget to drain the old crud out of the overflow bottle and fill with your new coolant mix.

I've done coolant flushes on more AE92's than I can count, this method always works. You dont end up with a gurgling heater core or flakey idle after the change if you follow these directions.

Edited February 24, 2010 by CHA54

[NightFlight]

Here's how to do it...

-Set the heater to HOT inside the cabin

-Jack car up as high as you can and put it on chassis stands

-remove passenger side splash tray to gain access to drain ***** and lower radiator hose

-get a large bucket to collect the old coolant

-place bucket under drain port and undo drain *****, once it starts draining undo the radiator cap to increase the flow rate

SNIP

I've done coolant flushes on more AE92's than I can count, this method always works. You dont end up with a gurgling heater core or flakey idle after the change if you follow these directions.

Thanks for that.

So to sum up:

1) The handbook going on about the need to drain from the ENGINE drain plug is wrong for this model?

2) You recommend replacing the thermostat and thermostat gaskets with each coolant change?

3) Do you have the litre capacity of this unit? How many total litres does the coolant system hold?

The AE92 is part of the 6th generation of Corollas. You'd have through Toyota would have made the process a little bit more user friendly by that stage...

Edited February 24, 2010 by NightFlight

[CHA54]

Doing the intermediate flush with normal water negates the need to undo the drain bung on the block.

the AE92's dont have a lot of space to fit the aircon compressor, powersteering pump, alternator etc so once the brackets to mount those are in place, access to parts on the block that was designed 6 years earlier becomes restricted. Same as the oilfilter access is difficult in a FWD configuration.

Buy the 4L concentrate coolant bottle from toyota, that will make a bit more than 8L of coolant which is more than enough to fill the system.

If you dont have a record of when the thermostat was last changed, I definately recommend replacing it. On AE92's I also take the radiator to a radiator shop to have the bottom tank removed and steel rods punched down the cores to clear the blockages. If it's the original radiator I'll guarantee it is at least 40% blocked. This radiator service costs me $80 cash when I drop the radiator off ready to go.

Edited February 24, 2010 by CHA54

[NightFlight]

Doing the intermediate flush with normal water negates the need to undo the drain bung on the block.

SNIP

If it's the original radiator I'll guarantee it is at least 40% blocked. This radiator service costs me $80 cash when I drop the radiator off ready to go.

Thankyou CHA54 for all this information.

It is really appreciated. B)