Bleeding the Radiator

[kawasakizxr]

Hi doing a coolant change on my zxr 400 today I have done this job before.

Drained the old coolant by disconnecting one of the radiator pipes.

The manual says there are drain plugs on the engine however i have never used these as i worry i wont get them to reseal.

I let the old coolant drain for a good 30 mins. Fitted the pipes back and filled slowly with coolant. At just over 1 litre the radiator was full.

I squeezed the radiator pipes then ran the bike for a few seconds and put a bit more in. I have around 1.25 litres in the radiator. i ran the bike again for a few minutes.

I have rocked the bike side to side and also squeezed the pipes again. I have seen some air escape but not much. I have now filled the reserve tank to the upper level and i have used a total of 1.75Litres

The manual says with both the radiator and the reserve tank full i should need 2.3L so i am a bit concerned that i dont have enough coolant and dont want to overheat my engine.

If anyone could give me a idea of whats wrong that would be great.

Thinking about it maybe i still had some coolant left over in the engine that didnt drain fully ?

Thanks

[Aff]

Open the rad cap.

Run the engine until the fan comes on.

Top up along the way when necessary.

Put the rad cap back on.

Ride bike.

Win.
____________________
Current Bikes:Honda 929RR Fireblade, Honda CD200 Benly (Project), Stomp Z2 140
Electric Bike Project

[kawasakizxr]

And i wont overheat and damage my engine ?

Just looked at the drained coolant there isnt a lot thats come out

Is this because i havent used the drain plugs on the engine ?

I havent used the engine drain plugs before because i dont have any washers to seal them with. Also there sat right at the top of the engine so if i was to loosen them i would have coolant evreywhere.

Coolant came out clean slightly green but looks fine. I have also fitted a new coolant filter.

Thanks.

[Llama-Farmer]

Drain from the water pump, shouldn't need to replace the washer, should seal up fine again as long as you don't overtighten it, use a torque wrench.

[ws4936]

[davebike]

Run until hot but don't wait for fan it will not come on unless the system is pressurised as the fan switch trips at 102 C and water boils at Sea level air pressure at 100 C !!

Dave
____________________
Dave
NC750Xdct + others at work !
davebike1@gmail.com

[kawasakizxr]

Tried to bleed it again this morning.

Start the bike and within a minute iv got coolant overflowing out of the radiator i cant get the engine warm as theres coolant going evreywhere.

Starting to worry me as theres now less than 1.75l in the whole system including reserve.

[Wafer_Thin_Ham]

[kawasakizxr]

I drained it from the hose that connects the radiator to a small length pipe that connects to the water pump. so when it was draining i had coolant draining out of 2 seperate pipes if that makes sense.


How do i tell if my thermostat is goosed ?

[Wafer_Thin_Ham]

[SQL]

[kawasakizxr]

Ok what il do is put the radiator cap on and just leave it and presume its full and check regually.

I still need to change my oil so cant take it for a ride just yet.

[Wafer_Thin_Ham]

[kawasakizxr]

Yeah will do

Thanks for your help

[Llama-Farmer]

[kawasakizxr]

yeah doing both the oil and filter

[kawasakizxr]

Drain bolt washer is now stuck on the drain bolt

Normally they just fall off

I have always replaced the washer evrey oil change, The bolt was new a year and a half ago

Have tried pressing it of with my hands and its stuck on there. The washer has marks on looking as though its been crushed too much.

Not having the best of luck with this bike simple jobs i have done before

[Aff]

[Llama-Farmer]

[CaNsA]

dude, have you join up to ZXRWorld yet?
https://www.zxrworld.co.uk/zxr400oc/index.php

[Hetzer]

I opened all the drain holes on mine and also ran the engine with a hose putting water into the rad for that fully flushed effect.
____________________
"There's the horizon! Ride hard, ride fast and cut down all who stand in your way!"

[Llama-Farmer]

[Robby]

This is why you should always follow the manual to do a coolant change. Half of it is in the rad, half of it is in the engine.

If the coolant is old, then I tend to drain it, fill with water, run the engine up to temp, then drain the water and refill with the correct coolant. Don't mix different coloured coolants.

If you're not getting enough coolant in and the thing is overheating, then you haven't filled it properly.
From an empty system, I tend to do the following:
1. Put in half of the coolant through the radiator.
2. Slacken off the lowest drain screw and make sure that just coolant comes out - it may also work as a bleed screw. Tighten it back up.
3. Put the rest of the coolant in until the radiator is full.
4. Look for any other bleed screws, open them and make sure only coolant comes out.
5. Fill the header tank to the min line.
6. Start the engine with the rad cap off. Run it until the thermostat opens, at which point the coolant may drop. Turn off the engine, let it sit for a minute, top up the rad.
7. Put the rad cap back on, fill the expansion bottle to the max line.
8. Run the engine up to temp. If there is any air in the system, it will get forced out of the rad cap into the expansion bottle.
9. Let the system fully cool before doing anything. This is the most important bit, as the system cools it will draw in any required fluid from the expansion bottle. This will not happen if you remove the rad cap.

The easiest way to cock up a coolant change is to try to take a short cut, then worry too much and keep removing the rad cap. It's a self-balancing pressurised system, but if you remove he rad cap it won't self-balance.