Coolant flush process

[knyte]

Oh I totally I follow you.  My CRF250L has a maint interval of what, 12,000 kms...but I bet there are those who change the oil every 3000 or 5000, and the filter is scheduled for a change every 25,000 kms - I don't know too many who would wait that long - just change the filter & oil at the same time.  I suppose that's part of the allure of owning the machine; babying it.  We want it in top form at all times, to look good and be in the best running order possible.

[maximNikenGT]

Alright - so finally had some time to work on the coolant replacement. I have one of those coolant testing tools that will measure the specific gravity of your coolant to determine whether it is of the appropriate mix/quality to meet expected freezing and boiling temperatures. The tool is especially helpful for dialing in the right mix of coolant to water if you live in climates where you might get abnormally low temperatures or unusually high temperatures. 

So detailed steps are as follows:

1. Use eye protection and latex gloves. Coolant in your eyes is bad as is prolonged exposure to your skin. Also, immediately rinse off any painted areas that get splashed by coolant with water since coolant eats away at painted finishes. 
2. Set bike on level ground and use side stand. Use of side stand will supposedly help the coolant drain from the bike's pipes a little faster than if you use the center stand. 
3. Lay down cardboard/tarp and coolant catch tray under bike in case of spillage.
4. Remove coolant drain bolt located on the bottom left-hand side at the bottom of the water pump cover. Be sure to place catch tray here. Some coolant will leak out upon bolt removal. 
5. Remove upper fuse box cover that sits directly behind the radiator cap on the upper right-hand side. I was a little surprised that you must remove this cover secured by both a push pin fastener as well as a 5mm hex bolt. If you ever have to add emergency coolant while you're on the road, you'd better have a 5 mm hex bolt and a paperclip or else you cannot even loosen/remove the radiator cap. Do not loosen the cap until you have removed the water pump drain bolt first. As soon as you remove the radiator cap about 2 liters of coolant will flow out the coolant drain bolt on the opposite side. 
6. Use same 5mm hex bolt tool as well as a TINY T5 Torx bit to remove the cover that secures the coolant overflow tank and cover. You can go ahead and empty out the coolant remaining in the overflow tank while you're waiting for all the coolant to drain from the drain bolt in step 4. 
7. Squeeze some of the radiator hoses to help drain any coolant caught in the hose bends.
8. Note that the front of the overflow tank and the overflow tank cover have a slightly unusual front connector set up that utilizes a mounting bracket between the mounting hole of the overflow tank and the overflow tank cover (in comparison to the relatively straightforward mounting of the rear hex bolt fastener). This front connector also uses a VERY small T5 Torx bit head. Putting it back together was a little more detailed and took a bit more time vs. taking it off because of the specific placement as well as ensuring that the overflow drain tube didn't get caught/pinched by the rear hex bolt upon reassembly. 
9. Use a turkey basting looking syringe or pour 0.25 Liter of fresh coolant in the overflow tank. Fill level should fall between upper and lower lines. Put the coolant overflow tank and cover back on. 
10. Once all coolant has been drained, secure the coolant drain bolt back on using a fresh/new crush washer and tighten to 9 N/m with a torque wrench. 
11. Strongly suggest using a long neck funnel to add coolant to the radiator intake hose to help prevent coolant spillage and potentially impacting the paint. Unfortunately, the Niken's upper cowling is so big and curvy that it literally prevents you from putting a straight funnel overhead. Add coolant slowly until you reach almost 2 liters of coolant. 
12. When you finally top off the coolant intake, fire up the engine and let it idle for about 20 mins or until the engine reaches regular operating temperature (at least 140-165 degrees F) to let the coolant burp out any air pockets as well as allow the thermostat to turn on and run the coolant through the entire system. One has to hit the engine operating temperature to make sure that your engine temperature isn't fluctuating due to air pockets still stuck in the cooling system (toggle your engine temperature and see if it's jumping up and down). If you see weird engine temperature fluctuation then most likely you have air in the system that just needs to be burped out. 
13. After reaching engine operating temperature, shut off the engine and check coolant levels and determine whether any additional fluid is needed and top off as appropriate. 
14. Once you're satisfied that the bike isn't having wacky temperature readings because of air pockets stuck in the system and your coolant levels shows as being between upper and lower limits of the overflow tank, secure the fusebox cover hex bolt to 9 Nm with a torque wrench and put the push pin fastener. 
15. Dispose coolant at your local auto parts store/auto service shop for recycling. 

Coolant tester tool.

Coolant tester - cold side markings. NOTE: Dark red/triangle needle pointing to freeze point temperature scales is your coolant level reading. The upper dark red/much smaller needle is used to make sure that you're reading the  tool from an absolutely level position. 

Coolant tester - hot side markings. NOTE: Dark red/triangle needle is your coolant level reading. The upper dark red/much smaller needle is used to make sure that you're reading the  tool from an absolutely level position. 

Anti-Freeze and Coolant tester tool is used to verify what your coolant will actually perform at (in terms of freezing  and boiling temperatures) based upon its mix of coolant to water and its age/condition. The tool operates by measuring the specific gravity of the fluid being tested.

You insert the pipe end into the fluid that you want to test. Make sure that it goes all the way up to the level indicated near the top of the tool and hold it perfectly vertical to see where the secondary big needle falls.

Example. If you use this tool in regular 100% tap water, the needle will fall right at or below the FREEZE POINT indicated in red with white text above.

Typically the needle should fall at the -10 degrees F / -23 degrees C for standard 50% coolant plus 50% distilled water mix. If you're operating in more extreme conditions then mix as recommended by the coolant manufacturer. 

Needed a long neck funnel to get the coolant in after removing the radiator cap. 

Left hand side picture of the water pump cover. Bolt to be removed is at the 5 o'clock position of the water pump cover in between the bottom radiator hose and the clutch cover. 

Location of right-hand side radiator cap which cannot be opened until you remove the fusebox cover directly behind it first. 

Hex bolt that secures the fusebox cover plate as well as the radiator intake hose. 

The coolant overflow and cover plate with its unusual front and rear mounting set up. Note front gap between overflow tank and the outer housing is intentional since a metal bracket MUST fit between the two at this point. This was not readily apparent when removing the housing and you'll find out reinstallation is a bit trickier as a result of this nuance. 

Also verify upon reinstallation that the hose that sits on top of the overflow tank does not get pinched by the rear hex bolt. 

Niken upper cowling is so big and curvy that you have to use a long-necked funnel of some kind otherwise you cannot pour coolant without making a huge mess. Now my OEMTools coolant funnel above comes with various sized caps to secure the filler tube to the radiator. Supposedly it's a size "C" cap. However, the size "C" cap that allows the long filler tube through was too narrow to fit on top of the Niken radiator inlet.

Not sure if I have to bend the metal prongs on the OEMTools cap in order to make it work, but it did NOT fit mine with zero fuss. 

It's pretty late so I didn't want to wake neighbors by idling in my driveway/burping the coolant so will save that step for tomorrow. 

Burping the coolant is important because if you have any air pockets in the coolant system, what happens is that your engine will heat up these air pockets as you ride. The resulting engine operating temperatures will cause the air pockets to convert the air to steam which could trigger high temperature warnings when it circulates through the thermostat. The resulting high temperature signals could trigger high engine temperature warnings on your instrument display in addition to under very extreme scenarios (e.g. riding without any coolant/running pure water instead of coolant in your system) potentially triggering engine shut down to prevent catastrophic engine meltdown /cracking and a very large repair bill.   

 

 

Upper bolt securing the coolant overflow is a tiny Torx bit that I wouldn't normally carry as part of my emergency motorcycle tool set.

The overflow pipes, overflow tank and overflow tank cover. 

 During engine idling I added a little adapter to help control/prevent coolant air bubbles from bubbling on to the surrounding painted areas. 

After idling the engine up to an operating temperature of 170 degrees F, turned off the engine. Topped off the radiator intake with coolant and then capped the radiator inlet closed.   Set bike on center stand to and put a light on the backside to check coolant levels and we're done. 

Edited April 17, 2023 by maximNikenGT
Corrected location of certain photos

[Ride365]

So did you test the coolant before you did all that work?

[maximNikenGT]

3 hours ago, Ride365 said:

So did you test the coolant before you did all that work?

I did test at the overflow tank but couldn't from the radiator inlet because the coolant level was too low to be picked up by the tool.

The overflow blue coolant in the tank did test ok but I was already committed to replacing the fluid since I was at the 4 year mark anyways. 

Stock Yamaha coolant was a blue color and I swapped with Prestone lime green coolant. 

[cropduster]

Pretty good guide, thanks for sharing. I followed it yesterday while changing the coolant on my 2019 Tracer 900, as the steps are pretty much the same (except for removing a side fairing beforehand on the Tracer).

The one thing I did differently (after reading about all the frustrations with the coolant overflow reservoir spacers) was to NOT remove it from the frame. Instead, I just used a cheap $5 fluid pump from Harbor Freight and pumped the old coolant out. To fill it up, I attached a vinyl hose to a funnel. I reckon some residue is probably left in the reservoir by doing this, but probably less so than is left in the radiator hoses.

 

I felt like sharing this step, as it probably saved me a good 20 mins and a lot of cursing (based on all I read about these spacers).

[maximNikenGT]

Glad it helped at least one fellow rider! 😀

[2and3cylinders]

The Bomb!!!

https://www.amazon.com/UView-550000-Airlift-Cooling-Checker/dp/B0002SRH5G/ref=asc_df_B0002SRH5G/?tag=hyprod-20&linkCode=df0&hvadid=312174136943&hvpos=&hvnetw=g&hvrand=2377647730814941359&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9021758&hvtargid=pla-435688359104&psc=1&tag=&ref=&adgrpid=63790029762&hvpone=&hvptwo=&hvadid=312174136943&hvpos=&hvnetw=g&hvrand=2377647730814941359&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9021758&hvtargid=pla-435688359104

[maximNikenGT]

On 2/4/2023 at 12:08 PM, TomTracer said:

How many of us follow that schedule on cars? Most I'd guess are more anal about our bikes.

I admit that I'm a stickler for maintenance on my car because I keep my cars in excess of 100k+miles. Frequent and regular maintenance prevents much bigger problems further down the line. No such thing as a "lifetime fluid".