Author Topic: Best way to locate a coolant leak? (Read 10531 times)

lolliver · « **on:** 10 July 2012, 11:58:24 am »

Hi all!

I've noticed recently that after running the bike on short journeys there are lots of drips of green liquid on the left hand side of my engine casing. (I'm assuming it's coolant?) What's the best way to locate where this is coming from?
I've had a good look around but it's such a rats nest of hoses etc. around there that it's difficult to see where the problem lies.

Thanks,
Ollie

marksfazer · « **Reply #1 on:** 10 July 2012, 12:28:54 pm »

You really want a coolant pressure tester kit to identify where the leak is coming from, but if you don't have one or can't borrow one, then its a case of stripping everything off to allow you good access and get in there with a torch and run the bike until its hot. Be carefully tho, hot fazer's will burn!!

lolliver · « **Reply #2 on:** 10 July 2012, 12:43:21 pm »

Cheers for the reply! I don't have access to a pressure tester kit and I don't fancy pulling hoses off willy nilly. How long roughly would a mechanic take to find the leak? I don't fancy paying £££ to have this looked at!

Ollie

darrsi · « **Reply #3 on:** 10 July 2012, 02:03:49 pm »

You sure it's not just on the left side because you lean the bike on the side stand?
I'd start by lifting the tank up and make sure your cap and clips are all tight around the thermostat housing, which is right underneath the front tank bolt in the top front of the frame.
If you're losing coolant it'll need topping up, and make sure the level is okay in the overflow tank as well, which you can see by looking under the right side of the seat from the back looking forwards.(the white container)
You really need the bike on the centre stand for that though, i dunno if you've fitted it yet?

Fazerider · « **Reply #4 on:** 10 July 2012, 02:23:49 pm »

You don't need any fancy equipment to check this. If the leak does only occur under pressure, then running the engine until it's hot will achieve that.
I'd look closely around the radiator as a first place to check, it's wafer thin aluminium and subject to corrosion and impacts.
But, as Darrsi says, top up the coolant level before investigating.

caretaker · « **Reply #5 on:** 10 July 2012, 05:39:58 pm »

had a similar problem once. i shoved kitchen roll in and around as many hoses and joints as i could and eventually traced a soggy one. mind they dont catch fire though!

Captain Haddock · « **Reply #6 on:** 10 July 2012, 06:48:44 pm »

Dry well and spread some chalkdust around all the hoses and joins, take it out and thrash it, leaks will show easily, I use an aerosol can of crack testing developer spray for this sort of job (usually used with penetrating dye) as it drys as a fine powder and makes leaks stand out well.
You can blow most of the powder off afterwards with a good pressure airline and wash the rest off.

lolliver · « **Reply #7 on:** 10 July 2012, 08:20:43 pm »

Hello folks.

I thought that the overflow tank was where I was supposed to be topping my coolant up (it was empty yesterday), so I went outside and topped it up to full last night.. =/

Anyway, I only really do 2 mile trips on the bike to work and back every morning and afternoon and it leaks religiously when I get to work and when I get home. I took the bike for a proper blat this evening (40 miles) and there was no leak at all.

I took the tank off and couldn't see fluid anywhere and I took the radiator filler cover off and it was all nice and clean inside.

Is there any chance that this random coolant weep is being caused by such short trips on the bike every day?

Also, no I've not got the centre stand on yet! Turns out that it can't pivot due to the position of the exhaust. Gunna deal with that shortly

darrsi · « **Reply #8 on:** 10 July 2012, 09:05:04 pm »

This does not sound good at all, leaking religiously is never a good thing

You need to fill the coolant to the top of that filler cap under the tank, very slowly, so that you don't get air bubbles in the system, sooner rather than later!

Then with the cap still off start the bike and gently rev the engine to get rid of any trapped bubbles for about 1 minute, then top up again if needed.

As for the rear expansion tank, it should be no higher than the line in the middle when the bike is upright.

Short trips don't have anything to do with it, once the system is airtight the fluid won't really go anywhere and your levels will more or less stay the same all the time. You should check fluid levels regularly anyway.

If you seriously can't find any leakage anywhere, my next suggestion would be a radiator flush, because if you have a scaled up system that can cause the bike to overheat, then boil and dump the fluid.

Fill it back up first though then examine it again after you've ridden it, it may not be leaking because there's not enough coolant left to leak!

If you haven't got a Haynes manual yet i would seriously suggest you get one. You can download one on here to browse through but it doesn't beat having it next to the bike when working on it.

Nobody likes a greasy computer!

lolliver · « **Reply #9 on:** 10 July 2012, 09:07:54 pm »

Hey, cheers for the speedy reply! I think we might have crossed wires though, I meant that there's no mayonnaise on the radiator filler cap. There's a semi-cloudy green liquid right up to the lid basically.

darrsi · « **Reply #10 on:** 10 July 2012, 10:36:27 pm »

It was more than likely yellow anti-freeze, it's like a luminous yellow when new but will obviously discolour after being pumped around your engine.

If you are saying that the header tank was full up but not the expansion tank, then i would guess a rad flush is needed?

It 'could' be coming out of the thermostat cap because it's overheating due to clogged up pipes?

When it cools down it sucks liquid from the expansion tank to fill it back up.

Shorter trips in traffic would heat up the engine, whereas the longer trip you did would have air cooled the engine as well.

In this climate i normally put the rad flush in, fill up with water then ride with it in for 2 or 3 days, so that it gets time to do a proper job.

Obviously don't do that in winter as the water will be prone to freezing, with no antifreeze in the system.

Then empty out, flush with a hose (you're allowed now) and refill with a good motorbike antifreeze, from a bike shop, i would suggest a ready mixed one. (the yellow one is good stuff)

Don't put any old crap in there because it'll cause it to clog up again quicker in the future.

I'd still go over the jubilee clips on any piping though, make sure they are firmly tightened (not too tight), and also as Fazerider suggested, just let the bike tick over, with the tank safely propped up, and if it overheats, or you have a split somewhere, you'll see where it's coming from hopefully.

lolliver · « **Reply #11 on:** 11 July 2012, 09:12:57 am »

Ahh ok, yellow anti freeze makes more sense.
And yep, I'll take your advice on the rad flush, cheers!.

Sorry for all of my questions, never had a liquid cooled engine before! I came straight from a GS500 (imagine my surprise when I yanked on the front brake on the Fazer for the first time

)

I'll keep ya posted.

Ollie

lolliver · « **Reply #12 on:** 11 July 2012, 01:04:22 pm »

Just thought I'd add a quick update, rode home for lunch and noticed that the leak's coming from the little hose underneath the second carb in from the left! Still gunna flush the radiator anyway as I've never done it before and it'll be interesting

darrsi · « **Reply #13 on:** 11 July 2012, 01:24:37 pm »

I'm sure someone will correct me if i'm wrong, but i think the smaller hoses around that area are to do with the 'carb heater circuit' which flows warm water around the carbs to avoid 'carb icing' in colder weather.
The pipes are just a bit too narrow for the job and get blocked fairly easily.
That's not saying you haven't got a faulty hose though either?
Go ahead with the rad flush, but i'd definitely leave it circulating in the engine for 2 or 3 days before emptying it out, and maybe take the bike for a good run so that it's pumped around the system a bit harder at warmer temperatures to give it a good cleaning.
Here's a link for parts if need be: http://www.yamahascooterspares.co.uk/spares/epc2.asp?modelID=9655&PageiD=11&m=YAMAHA+FZS600+FAZER++++1999+CARBURETOR&uID=0

lolliver · « **Reply #14 on:** 11 July 2012, 01:39:10 pm »

Cheers Darrsi,

That's great, I'll grab a replacement 54 or 55 (need to look at the bike again after work!) and a couple of clips then. Thanks for all the help with the diagnosis

Ollie

Lazarus · « **Reply #15 on:** 11 July 2012, 02:14:29 pm »

hey lolliver.

I had a leak from my coolant pipes although it was fairly easy for me to find. (right above the wet patch on the ground was the pipe that seem to have lost its seal.

I decided to flush the coolant whilst repairing. this isnt something I had ever done before - im a relative newbie when it comes to bike maintenance.

the leak for me was coming from the pipe that you can just see in the photo below

https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-snc6/9125_146879701447_6564283_n.jpg

at the front of the belly pan, you can see the elbow of the pipe that was leaking. the clip had somehow "lost its grip" so I replaced with a stainless steel jubilee clip

when you are replacing the coolant, remember to replace with one that is designed for aluminium engines.

good luck - if i can do it then it isnt difficult.

lolliver · « **Reply #16 on:** 11 July 2012, 02:53:00 pm »

Cheers Lazarus!

When I get home I'll get the hose off and have a good look around it. Hopefully I've just lost the little clip, and won't have to buy a new hose

Mine's literally a tiny little hose, so it's only dumping a few ml's of fluid every trip luckily.

And yeah, I won't grab the cheapy stuff from Sainsburys garage like I normally do. Someone ^ mentioned the yellow stuff, so I'll try and grab that.

Lazarus · « **Reply #17 on:** 11 July 2012, 07:38:55 pm »

i got mine from Halfords (circa £13 if I remember). Ready mixed 1:1 ratio
let us know how u got on.

little tip if you arent aware. I use a 2 litre empty plastic bottle cut in half (length wise) to help drain the coolant - the "cap" end fitted nicely under the drainage plug hole and routed the coolant into a bucket. mind you - it fecking comes out fast when you remove the radiator cap!.

darrsi · « **Reply #18 on:** 12 July 2012, 06:39:58 am »

Got mine from Hein Gericke, but this is the cheapest i found online, but you'll have a few days wait by the looks of it!

http://www.ebay.co.uk/itm/Motul-Motocool-Expert-Motorcyle-Engine-Coolant-Fluid-1L-/370589635853?pt=UK_Vehicle_Oils_Lubricants_Fluids&hash=item5648dd150d#ht_1675wt_1139

Lazarus · « **Reply #19 on:** 12 July 2012, 08:19:08 am »

need to have two of them then Darrsi - Fazer 600 needs 1.95 litres iirc.

i got this from halfords :

http://www.halfords.com/webapp/wcs/stores/servlet/product_storeId_10001_catalogId_10151_productId_185166_langId_-1_categoryId_255224

£11.99

darrsi · « **Reply #20 on:** 12 July 2012, 10:09:00 am »

All depends if you've filled your expansion tank up to the top or not i s'pose ! ! !

Lazarus · « **Reply #21 on:** 12 July 2012, 12:00:07 pm »

Quote from: darrsi on 12 July 2012, 10:09:00 am

All depends if you've filled your expansion tank up to the top or not i s'pose ! ! !

just re-read my last post Darrsi and dont think it came over too well.

wasnt trying to be arsey about it - im by no stretch of the imagination mechanically minded and i didnt intend the post to be taken that way.

The only reason I know is that i have just replaced my coolant and needed the majority of the 2l bottle (and yes - i filled up the overflow)

darrsi · « **Reply #22 on:** 12 July 2012, 12:36:19 pm »

No worries, i was referring to 'lollivor' who topped his right up actually!
If you put too much in it'll just chuck it out of the expansion tank drainage pipe anyway when the engine gets hot.
'lollivor' if you're reading this when you've replaced your dodgy hose, if you don't syphon a bit out of the expansion tank down to the correct level, expect the excess to be dumped on the floor.
Just thought i'd let you know before you think you have another problem, the fluid needs room to expand when it's hot.
Not enough room? See ya later, out it goes!

lolliver · « **Reply #23 on:** 12 July 2012, 02:53:11 pm »

Haha oh ok. Thanks for the advice

Went on a bit of a shopping spree on the ajsutton website yesterday and bought a load of bits that the bike needed, so hopefully if it arrives in time I'll crack on this weekend and get stuff done.

Ollie