Went for a ride last night and had a bit of an issue with my ZX-14. When I stopped for a coffee I noticed coolant leaking.

Temperature at the mid point (3 bars) when riding, climbing one bar (4 bars) when slowed down and finally parked. This is what I would call norm for the bike. Noticed coolant dripping from the bottom mid point of the bike after I had shut the bike off. I left the bike to cool down and had coffee. With the bike cooled down I managed to reach up and remove the rad cap. I stuck my finger into the rad opening and could not feel any coolant. I observed that the coolant reservoir was full to the brim. So my thoughts are that I have a bad rad cap that is releasing coolant to the reservoir, and the reservoir is overflowing as a result, hence the puddle.

I had a 500ml bottle of water with me. I removed the right hand dash side panel (note to others buy Allen keys and put in tool pouch for fairing removal purposes)and was able to pour the water directly into the rad. It took all 500ml. I figure the coolant leak was about 150ml (I filled my water bottle from the restaurant, poured out some water onto the ground to form the exact same size puddle and observed that it took about 1/4 of the bottle. So I believe that the water missing from the rad (roughly 500ml) was all accounted for (150ml puddle on the ground and the rest in the coolant reservoir).

The coolant leaked out immediately after I shut off the bike, all with 2 min, then stopped. The fact that I could account for the liquid makes me believe that I was not losing any while riding (plus their was not signs of coolant sprayed up on the bike anywhere. I started back home, watching the temp gauge like a hawk. Mid point (3 bars) while riding, climb to one bar when I pulled into the little town and slowed to 50km (30 miles). Parked and observed the same leak. This time the rad only took 250ml to top it up.

Has any body else had this problem? I read through some threads here and see that coolant expelling was discussed a couple of times but never really concluded (one member Peter seemed to have had a problem). I going to stop in at local rad shop and see if they can test my rad cap. I also called up a buddy to see if he has a pressure tester that I can place on my rad and observe the pressure being created. This should hopefully allow me to determine if the rad cap is faulty or was it doing its job.

As far as coolant goes I changed the coolant at the start of this riding season. I have put on 2500km on some pretty hot days and not had a single issue. I use Motul Motocool Expert (high boiling point 133°C/271°F) it is a straight non mixing coolant product.

Any thoughts would be appreciated.

Spyglass

* Last updated by: spyglass on 7/26/2012 @ 12:24 PM *

Spy take off your inner shrouds strakes and lower fairings,then you should be able to find the leak easily.I wouldn't be comfortable continually topping up.It's hopefully something cheap like a hose or gear clamp.I had a leaking hose on my hose 07 when it was new,it was a loose clamp

The top up was only to get my sad sack self home (was 2 hours up the Fraser Canyon). I pulled the fairing off last night when I got home to make sure that there was not leak anywhere. Hoses all fine, Rad fine. The leak is the reservoirs overflow tube.

Dealer did not have a stock replacement rad cap (1.1 bar = 15.9 psi). It sounds like most people are replacing the stock cap with a 1.6 bar (18.4 psi) cap - same one that comes factory on the ZX12. I ordered one and it should be here Wednesday.

Tonight I am going to fill my system up, ensure that there is no air trapped anywhere. Then I will pull the discharge hose, that delivers the coolant from the rad neck to the reservoir, from the reservoir and install a pressure gauge on the end of it. I will let the bike warm up. I will feel the hoses to verify that the thermostat is opening and releasing water from the engine and cycling it through the rad. I will check the whole of the rad surface to make sure the there are not cold spots. I will place several Fluke temperature sensors on the bike and use my infrared gun to spot check. Then I will wait to see if the rad cap releases coolant and at what pressure.

The new rad cap is $44.00 so I am hoping that it will be the solution.

Spyglass

You don't suppose maybe you got an air bubble trapped in that rad line or something do you?Maybe a fluke deal?Your water pump's doing okay,yes?Any signs of leaking around that?Pulling air in there?

* Last updated by: Grn14 on 7/26/2012 @ 8:08 PM *

I have thought about this problem all night and all day long. The easy one step solution part of me wants to believe that the rad cap is possibly just faulty and instead of holding and allowing pressure to build to 1.1 bar (15.9 psi) is opening at a much lower pressure. The problem with this logic is the pressure/vacuum relationship of the cooling system.
As the coolant is heated is expands. Regardless of the rad caps pressure value (aside from the boiling point of the coolant) I should not have a void in the cooling loop. Water expands past the rad cap into the reservoir. When the coolant cools the pressure decreases and a slight vacuum is created which pulls the displaced coolant from the reservoir back into the rad. When my bike cooled down that night while I tried to enjoy my pie, coolant should have be drawn back into the rad. Finding a 500ml void is strange.

So at some point coolant must have found a way to leak from the system to create the void, or the rad cap possibly allowed air to be pulled in during cool down instead of coolant from the reservoir. I will have to just fill the system up, ensure that all traces of air are out of the system, and run the bike and observe it heat up and cool down several times in my shop.

Spyglass

This just started to happen spontaneously? No corresponding events maintenance-wise that fit the same time period?

"As the coolant is heated is expands."...yes..it does...BUT...that's NOT what's making it move from the Rad to the res.That's happening as the motor demands more fluid flow,or less.IF you start with a low reservoir amount...and the engine starts requiring more flow...what you're gonna get is an overheat issue..IF the res is way low....ending with a boilover.When it cools back down...your res and your rad are now gonna be even LESS...she's gonna get HOTTER next run...and the same deal's gonna happen all over again.IF you have a crack or a way for air to enter that closed system...via bad cap or whatever....it's gonna do just like you said...it's gonna pull air instead of the heavier viscous fluid.And your bike is gonna heat up.When she cooled down...where was the res level sitting?That's what you need to see...where the coolant level is IN THE RAD and IN THE RES when she's cool.That's one reason they say to check it when cool...besides the fact that you'll get a facefull of hot coolant if ya try to open that cap after she's warmed up....don't ask me how I know;)

I'd say...top off the rad(while cold)....fill the res to the upper level line...and go ride.See what that does.If either one is LOW...I mean...like LOW...you are gonna get an overheating situation.....That rad and res work together to keep the right amount of fluid moving at any given time in that cooling system.It's NOT just a 'boilover' catch bottle.You could just make sure those upper lines are clear there..just remove each connection at the cap...see if possibly ANY chunk of something got lodged in there.Easy to check.And your hose clamps...any of em TOO tight?Cutting into the hose where ya can't see it?And how ARE those hoses?worn out?Fluid fresh in there?or been around the block one too many times.You could have some corrosion going on in there...maybe the last guy just used plain water to fill?Who knows.

* Last updated by: Grn14 on 7/27/2012 @ 3:19 PM *

The cooling system is designed to allow for minimal expansion of the coolant during operation which is why there is a reservoir in place to begin with. The system operates under pressure (1.1 bar) to allow for the coolant to operate at higher temperatures without the coolant boiling. If the radiator cap is not keeping the system pressure near the design goal of 1.1 bar then the coolant boils. This causes air bubbles in the system which increases the system volume due to the displacement of the air bubbles. This is when you see overflow into the reservoir and ultimately the coolant ending up on the ground from the reservoir overflow tube.

A bad head gasket will also cause this problem when the combustion pressure is allowed to leak into the cooling system, ultimately overpressurizing the system and forcing coolant into the reservoir.

In your situation I think you're spot-on with your diagnosis of the bad radiator cap. I hate to hear that you were charged $44 for the cap though. Kawasaki P/N 49085-1066, the most current application for the ZX-14 can be had for $21.45 from several on-line discounters and should retail for approximately $29. Even with shipping you'd save enough for fresh coolant. Good luck with your situation. Hopefully you'll be back on the road this weekend with nothing more than a new radiator cap.

Update on coolant issue.

Before I started having this problems I would have described my bike as rock solid and predictable in regards to temperature. My bike would normally sit a 3 bars when riding. In slow moving traffic or in line ups it would climb to 4 bars and the fan would run to compensate.

This week I went through what I felt was a thorough "air purge" process (not that I felt I had any air in the system just wanted to be thorough). I made sure the rad was full. I ran the bike up to temperature without the rad cap on. The bike would get to 4 bars and hold there, the fan would cycle on and off, Everything seemed fine. I let the bike cool down completely. I repeated this process 4 times (run the bike at night & let it cool down over night). I tapped hoses, felt to make sure they were all full and warm, etc. I observed flow at the top of the radiator. I could increase rpm and see the flow increase. I felt the rad for cold spots to ensure that there was no blockage or issues with the radiator.

I purchased a 1.6 bar rad cap to replace the stock 1.1 bar cap. With the bike cold, I made sure the coolant was fully topped up (to the neck of the rad's internal sealing lip). I placed the new rad cap on. I made sure that the reservoir was filled to the "cold" level. I started the bike and let it warm up in my garage. The temperature climbed up to 4 bars and held there. Fan cycling as one would expect. I had my buddy keep an eye on it, with instructions to shut the bike off if temperature indicator climbed past 4 bars. I got dressed for a test ride. The night was cool 68 deg F. I was hoping that the new rad cap was going to offer me the solution I needed. I noticed that the bike sat at 4 bar with driving 50km/hr (30miles/hr). Normally the display would have dropped to 3 bars. I merged onto the highway 100km/hr (60 mile/hr) and it was several minutes before the display dropped to 3 bars. It held at 3 bars for the duration of the highway ride. I pulled on the highway and the temperature climbed to 4 bars. I pulled into a large parking lot and drove 20km/hr (12 mile/hr) for the length of about 3 football fields). As I pulled into a parking stall the display showed 5 bars. I shut the bike off. I dismounted and looked to see if any coolant was leaking onto the ground. No leaking. I looked at the reservoir and it was completely full (just to the brink of overflowing). I had a coffee and left the bike for about 40 min.

When I started the bike up to return home it was at 4 bars. It stayed at 4 bars for a while, then finally dropped to 3 bars 80km/hr (50 miles/hr). I slowed to 50km/hr (30 miles/hr) and the display climbed to 4 bars. I pulled into a gas station and the display climbed to 5 bars. I filled up, and hit the highway again. The display dropped to 3 bars for the highway ride home. Once off the highway I saw 4 bars. As I turned into my driveway the displayed climbed to 5 bars. I parked the bike for the night. The next morning I looked at the reservoir to see if any coolant had been pulled in as the bike cooled down. The reservoir level was 1/2 between the "Hot" mark and full.

I wonder if I am having a thermostat problem where it is sticking. I looked at the manual for the steps involved in changing it (that you Kawasaki for making it so quick and easy - NOT). I have to wonder why I can let the bike idle in my garage and never get a temperature spike (no airflow, low pump flow) but when out for a ride I have problems.

The little voice in my head keeps whispering (head gasket). I hate that little voice. I called 2 different shops and they do not seem to be able to come up with suggestions. Both shops have never stocked, ordered in, or heard of a thermostat problem on a ZX-14. I am using a top rated coolant product with a very high boiling point. My rad is spotless. There is no leaks in my system.

Tonight I am going to test it again. I will check for air, place temperature sensors at various points, and see if I can detect a clue. If anybody has any ideas or could run this thread by top rated experienced mechanic I would be grateful.

Spyglass

Spy I would think a leaking head gasket would show up in your oil,from easy to hard I would flush system,change and get an oil analyse,plug reading then compression leak down test

Hub's not here....your head gasket is FINE...DO NOT start messing with your bike Spy....didja read that other guy's post...about the lines being crossed?You didn't somehow mix em up putting on there didja?At any time...even before this.

You could tell immediately if your head gasket is shot by looking IN the sightglass....ANY FOAM?If there isn't...forget about the gasket.Just sayin.

Wait a minute...I thought you had a 14R....bars?IDK.....Next deal I'd go for is COOLANT...What kind are you using?When you originally did this Radiator thing....you checked the coolant,yes?WHAT did it look like?Color AND condition.BTW...I think your first cap was fine...this sounds to me like a perfectly good coolant system....with a small leak somewhere.Sounds to me like it's managing to pull air in there as you're riding...that's what it sounds like.To me.

* Last updated by: Grn14 on 8/10/2012 @ 4:01 PM *

Thanks for responses guys (Darryle & Grn14).

I did read the other thread where the member had swapped the two small hoses (I was all excited until I read the reason). I have never pulled those hoses off and have followed the top most hose all the way back to the reservoir so I know it is in the correct location.

My oil is clean and shows no signs of moisture of contaminants.

I have a friend who knows a guy, who knows a guy, that might have a coolant system pressure tester for a motorcycle (small cap). If it pans out I will surely test my bike.

Grn14 I do not have a 14R (have a 2008 14). Changed original coolant at the season. The coolant looked pristine. I put in Motul Motocool Expert (high boiling point 133°C/271°F) It is a straight non mixing coolant product. I put 3500km (2174 mile) on the bike this season before "the problem" appeared. Some of the rides were very hot days and I never exceeded 4 bars or had coolant expelled, or excessive transfer of coolant to my reservoir. As far as a leak in the system I doubt it. I have no evidence of a leak, but more importantly, when the bike cools down it does pull liquid in from the reservoir (one would think that if it could pull in air it would tend to do so over pulling back water).
At this point I would agree that my original cap was probably fine.

I sure hope it is not a head gasket. I can offer several arguments against it being a head gasket, but there is one fact that makes me wonder..... why does the problem not happen during 30 min if idling (under 1000 rpm) but happens when the bike is ridden and rpm is over 1000 rpm.

I will perform a few tests on Monday and report back. I had a ride planned for this weekend but there is no way that I would complicate other people ride with my current dog & pony show. I think I will leave the bike locked in my garage and head to the cabin and get in some Kayak time (my kayak does not have a radiator.... )- LOL

Thanks again for the input.
Spyglass

Spyglass, you can send a coolant sample to Polaris Laboratories in Edmonton, Alberta, to have it analysed for combustion gas leakage. It takes approximately 60ml for this test. I'd do this to determine if you have a failing gasket. It is very possible to have coolant leakage into the combustion chamber without having it leak into the lubrication system. This would be one possible cause eliminated if the results come back negative. You can get their phone number and call and get details and pricing. Just google Polaris labs Canada.

Good Luck!!

Thank you Fowvay. At this point being able to rule things out is helpful. I will see if I can get in touch with Polaris Laboratories and determine what I need to do.

I am going to dedicate this week and try and cover ever base to get to the bottom of the problem. I hope my efforts and the coolant examination can determine the problem.

Spyglass

I believe I have cured my overheating / coolant expulsion problem. I did not find a singular break in the proverbial chain, no clear smoking guy (more like a room full of smoke). It is fun how one looks at their bike when it goes from being rock solid and dependable to problematic and undependable.

Here is a brief run down of what I explored.

1) Crossed my fingers and changed the stock rad cap from a 1.1 bar(15 psi) to a 1.6 bar(16.4 psi). Than manual suggests a range from 14-18 psi. This was a quick and easy first swing. It seemed to be supported by the fact that I did not notice a high temperature indication on the display (I later learned that the temperature did read high after I shut the bike off and was not able to read the display). While it did not eliminate the expulsion problem, it did help raise the boiling point of the coolant, and as a result I experienced a slight less expulsion (fill the reservoir up full but not overflowing).

2) After I noticed the temperature spiking I turned my attention to the thermostat and flow. I removed the thermostat and tested in a a water bath solution c/w 2 thermometers. The stat was rated at 60 deg C (140F). It was opening late (74 deg C (165 deg F). I cut the valve portion out of the stat and placed the rim body back in place (wanted to ensure that I did not reduce any back pressure and rob any potential resulting flow from the oil exchanger path, which is in parallel with the block flow). I did not see any improvement with the stat removed from the system. From all the tests I have performed over the last few weeks I am 100% confident that the bike, once warmed up, never sees/enjoys coolant temperatures blow 80 deg C. I will not bother to put in another thermostat (perhaps if I lived in a cold climate and rode all year long it might be a consideration for faster warming up).

3) I tested the fan (again) to enure that it was repeatably coming on when expected and that the air movement was decent. It worked perfectly.

4)Pressure test of coolant system. My external examination did not find any hint of a leak, and all the coolant was accounted for). But to be thorough I wanted to be able to rule out a leak. If there was a leak it was allow a lower boiling point and could, like a bad rad cap, offer a tidy explanation. I assembled the parts needed to make the test (will post the device later). I tested my device to ensure it was accurate and free of leaks itself). The manual suggested a test duration of 6 sec to provide proof. I left my test on for 6 hours. The system did not drop a fraction of a psi.

5)I drained all the coolant from the system. I pulled the cover off of the pump and inspected the impeller (looked brand new, no possible slipping on the shaft, etc). I replaced the pump cover and decided to perform a real life flow test. I pulled the bottom "supply" hos off the rad. I connected it to a water bucket (that I maintained with a garden hose). I started the bike and could see the rate at which the pump moved the water from the bucket, through the complete system block, oil exchanger, and rad. Everything looked good.

6) The only step left was to consider the coolant. I had put in Motul's Motocool Expert at the start of the season. I had riding over 2500km with out any issues using it. I was told it was one of the best product on the market. I did not see am improvement using it (no lower bars, etc). It seemed to fall into step with the a 50/50 mix of anti freeze and distilled water. The Motul comes premixed. I decided to put in brnd new coolant of a different make. I bought Prestones Extreme coolant. This product also comes premixed. I noticed right away that it looked richer green, thicker, had more of a slippery feel to it. The Motul by comparison was thin, faint in colour.
I filled up the coolant system and bled out all the air by idling the bike without the rad cap on, tapping hoses, etc. I let the bike cool right down. I made sure the rad was filled to the top. I filled the reservoir to the "cold" mark. I took the bike for a test ride, stopping at various point to check the reservoir level. The reservoir level never changed. The bikes temperature display seemed to offer hope as well. It showed the former 3 bars while riding, 4 bars when stopped or trapped in slow moving traffic. It was the first taste of victory I had in the coolant battle.

7) Sunday I decided to give the bike the ultimate test. I 500km (300 mile) run on 37 deg C (98.6 deg F) weather. I headed up the Fraser Canyon and blasted up to Cache Creek and back. It was a very hot day. Even at 130km/hr the air felt like a hand dryer. I noticed that bike maintained 4 bars while riding. When I stopped at Cache Creek at the gas pumps I quickly turned my bike off. The display showed 4 bars and climbed to 5 after I shut the motor off. I looked at the reservoir...... not coolant being dumping in. I smiled, filled up and rode home (smiling & sweating back to Hope and a cooler valley floor).

So If I had to point a finger any any one thing it would definitely be the Motul Motocool Expert coolant product. Is The product crap? Was it old stock sitting for too long on the dealer's shelf? Did the year I have it siting on my shelf add to issue? Is any one else using Motul's coolant product, any issues or concerns.

Spyglass

You really need to put a thermostat back in (it is there for a reason)
1. It slows the flow of coolant down (so that it doesnt pass through the radiator to quickly)
2. It lets the engine get up to its operating temperature quicker
3. It controls engine temperature on cooler days
Engineers dont just put these things in your cooling system for the fun of it!

My 2 cents

Neil

Sheesh...you weren't kiddin!Full on test?....You should maybe think about opening yer own shop!LOL!!!!!Hope that coolant actually was the culprit....sounds like it.I'm also with Neil....I'd get that thermostat back in there...you living up North...could be very important and all.Good job...GLAD you took the time to answer back....so many guys don't.No one ends up knowing if their help actually 'helped'.

I DID see that somewhere...that Motul coolant...brushed it off though.I'd say...thicker is better....?????IDK.Green is green I guessLOL!Mine is quite slippery as well.

* Last updated by: Grn14 on 8/21/2012 @ 1:13 PM *

Neilp I am of the same camp as you. If a feature has been incorporated into a design there normally is a reason.
Thanks for your thoughts,

In the case of the thermostat on the ZX-14 it is for initial start up, and during operation in really cold temperatures (temperatures colder than what I experience during my 3 month riding season here). If the manufacture had intended the thermostat to play a more active role they would have sized the rad larger. Once the bike is warmed up the thermostat is wide open for the duration. Kawasaki has engineered their coolant system close to the bone for riding in general conditions. The engine temperature falls within what they feel is an acceptable range. For my bike it seems to be 80 deg C (176 deg F)to about 120 deg C (248 deg F). Ambient air temperature has a small hand to play. Airflow is the key balance between heat gain & heat loss. With a high rate of air flow the bike will run in the range of 80-100 deg C (over 100km/hr, 60mph). With a low rate of air flow the bike will run in the range of 100-120 deg C (20- 80 km/hr, 12-50 mph).

I have several RTD sensors kitted on my bike monitoring temperature. I am measuring the temperature of the coolant leaving the engine block (at the thermostat housing) and leaving the rad or at the pump. I am measuring either side of the oil heat exchanger as well. I use my infrared heat gun to measure exhaust, hoses, and various other spot readings.

Spyglass

Thanks for the info guys. All the comments and troubleshooting steps help me solved the my problem. I bought a 2010 zx14 that supposedly overheat on traffic, after basic troubleshooting and bleed the air by running the bike idle without the radiator cap until temperature stabilized and no overheating issue at all. Installed the radiator cap back and allowed the motorcycle to stabilized temperature on idle park in the garage, the radiator fan worked as expected. During all this process I was monitoring the temperature at different places of the cooling system with a IR Heat gun. At this point I was very happy with the results and assumed the issue was corrected BUT after turning OFF the motorcycle, 30 seconds later antifreeze will start leaking (about 7-10 oz) from the overflow container thru the overflow drain hose.
I replaced the radiator cap and the issue continued, followed the air bleeding sequence few more time without no success. Finally Spyglass mention about the inverted Air Bleeder and Overflow hoses and ..... that was exactly the problem..... If any body have the same problem of the motorcycle leaking from the overflow double check the hoses..

Thanks guys.. great info...