replacing coolant

Moderator: Moderators

Post Reply
dunkymunky
Posts: 13
Joined: Sat May 11, 2013 12:55 pm
My Bike: ZX400g

replacing coolant

Post by dunkymunky »

I'm having some issues with my cooling system. Being new to bikes I am hoping you guys can help me.

After a complete rebuild, I put in the correct amount of coolant back in. I was told by my local shop to put some of it in the rad and some in the expansion tank.

However, now when the bike gets up to temp, it appears to stick everything in the expansion tank, this has meant most of my coolant has ended up on the garage floor.

Is this the right way to do things?
adamm1704
Posts: 46
Joined: Sat Jun 02, 2012 7:30 pm
My Bike: Zxr400 H1

Re: replacing coolant

Post by adamm1704 »

The way i do mine is to fill the expansion bottle up to the full mark and then add coolant into the rad with the cap off and the engine running, keep adding coolant until no more air bubbles come out and then put the cap back on. Ive had no problems doing it this way and usually i use less coolant that is specified in the manual.
User avatar
RedexRobB
Site Admin
Site Admin
Posts: 7212
Joined: Fri Aug 30, 2002 7:37 pm
My Bike: ZXR400L3
Location: Ipswich, Suffolk

Re: replacing coolant

Post by RedexRobB »

Its normal for a bit of coolant to come out but not a whole expansion tank full.

Id say change your radiator cap and see how you go. If the spring has gone in that as soon as it gets up to temp then the coolant will quite easily expand and pump out into the expansion bottle which will also overfill and eventually out onto the floor.
Blaine zxr
Posts: 11
Joined: Thu Feb 07, 2019 9:10 pm
My Bike: Zxr 400 L5
Location: Cork Ireland

Re: replacing coolant

Post by Blaine zxr »

So as I'm also new to bikes I'm just after doing a service to my bike but I want to also change the coolant as haven't bike long and not sure of previous service interviles but basically can I just drain out old coolant and refill and off I go or does it need bleeding ? Thanks n advance biggrin
:excited :pmsl
User avatar
banner001
Track day God
Track day God
Posts: 2584
Joined: Sat Sep 24, 2011 3:27 pm
My Bike: ZXR400 L4
Location: Nuneaton

Re: replacing coolant

Post by banner001 »

How I do it, open the radiator cap and then drain coolant from the port on the coolant pump. When that is empty open the 2 drain screws on the cylinders. When it's all drained I then disconnect the pipe from the expansion chamber to the rad and empty that too.

This fully drains the system.

I then leave open the coolant pump drain port only and flush the system with a garden hose inserted into the radiator opening, then once that is running clear I close the pump opening and fill with water and do a full drain a few times...this will fully flush the system. Close everything off, fill with coolant and the job is done.
UK ZXR400 L3 (1993) - Fully restored and on the roads, my green beast!
JPN ZXR250 A2 (1990) - Revs to 19,200rpm... 'nuff said :smt003
User avatar
banner001
Track day God
Track day God
Posts: 2584
Joined: Sat Sep 24, 2011 3:27 pm
My Bike: ZXR400 L4
Location: Nuneaton

Re: replacing coolant

Post by banner001 »

As for bleeding, basically give all the hoses a good squeeze and make sure rad and expansion bottle are topped off, then run the bike up to temp until the fan kicks in, turn it off, wait to cool and the top-up.
UK ZXR400 L3 (1993) - Fully restored and on the roads, my green beast!
JPN ZXR250 A2 (1990) - Revs to 19,200rpm... 'nuff said :smt003
Blaine zxr
Posts: 11
Joined: Thu Feb 07, 2019 9:10 pm
My Bike: Zxr 400 L5
Location: Cork Ireland

Re: replacing coolant

Post by Blaine zxr »

Thanks very much for the advice and help I'll tackle it some evening this week biggrin
:excited :pmsl
Post Reply