Flushing Coolant System

[Guest Kris78]

Ok so time has come for me to flush my radiators and put new coolant in.

I have just purchased some liquid intelligence , engine radiator flush kit just for piece of mind.

Now my question is has anyone used CLR ( calcium lime rust) mixture to flush the engine and radiators ?

As this is cheaper and easily available at our local store compared to the liquid intelligence cleaning kit.

[MadScientist]

I would be hesitant to use CLR in an aluminum radiator. The organic acid active ingredients will dissolve some of the aluminum, which may possibly lead to a weak spot in a older radiator. Some people do it, but CLR cautions against use on brass, copper, and aluminum. Since the cooling system operates under pressure, I wouldn't do anything that would potentially weaken it.

As far as the liquid intelligence stuff, any manufacturer that doesn't list their active ingredients OR provide at least an MSDS (all the links on the liquid intelligence site return 404 errors) is less than reputable in my book. That stuff wouldn't get anywhere near my garage.

[PairOfAces]

Do Not use this crap ! Your system does not need it. If it has been filled with a distilled water coolant solution over the years there will be NO NEED for this. Look into your radiator with a light for corrosion. If you do not see any, and you won't, there is no need for this. Fill the system with 100% distilled water and run if you feel you need to rinse the system. Aluminum does not corrode unless it is completely neglected. I would assume it has been flushed since 2003. These caustic cleaners are BAD.

[Grum]

Hi Kris78.

Can I suggest you visit your nearest Honda car dealership and purchase a 5ltr container of Honda Type 2 Coolant. It is blue in colour, is pre mixed, borate and silicate free and suitable for all Honda engines, it has a 5 year life in your engine. Used it successfully in 3 previous VFR's.

Totally agree with PairOfAces and MadScientist, there should be NO need to flush your system with anything other than distilled water, doing this will ensure you don't have any compatibility issues with previous coolants.

Cheers.

Grum.

[Guest Kris78]

Hi all

Cheers for the replies , my main concern with flushing the radiators and engine was for piece of mind as I just purchased the bike. When I got the bike home I did the usual going over and service and I noticed the radiators were low on fluid and no fluid in the overflow ,I removed the radiator cap and noticed it wasn't clean at all and had brown colour stuff dirt/rust/sludge like stuff on it.

So I just flush with distiller water then and use good coolant

[MarkDetroit]

It sure sounds like the previous owner seriously neglected your bike. Likely did not use coolant at all.

With the rust you see, IMO, using a high quality flushing product makes sense. Just make sure this product is then flushed properly afterwards.

Don't go overboard and don't use CLR!

[Guest Kris78]

There were traces of coolant ,though the service history was a blur to old mate that owned it before me.

My local Honda motorcycle dealer knows the bike and confirmed it had been looked after and serviced.

So a flush a new radiator cap and some good coolant , what has been recommended by the local boys is this stuff :

Just waiting now on the spill less funnel kit ?

[MadScientist]

Engine Ice is roughly a 50% propylene glycol solution which is very close to the performance of ethylene glycol at 200F (thermal conductivity and viscosity are within 5%, in favor of ethylene glycol), I wouldn't expect to see any performance benefit from this. The only industry that really uses propylene glycol coolants are food service because it is non-toxic, but more expensive and similar in performance. Pure water outperforms them both by a rather large margin in terms of cooling ability. Neither provide a large boiling point elevation until the concentration is so high that it is useless as a coolant; your main source of boiling point elevation is the increased pressure in the cooling system. Pure water at 14.6 psig boils at 246F(119C). Ethylene or propylene glycol only add about 10F to this at 50%.

Given that you don't encounter freezing temperatures in Darwin, I would mix either this product or an ethlyene glycol product (like the honda factory coolant) to the minimum recommended concentration. DOW chem recommends 25% glycol (eth or prop) to maintain condition of seals and mechanical components, and prevent growth of microbial contaminants.

Last thing, I hate that bottle. If you are going to use strong language like "proven" then you better cite peer reviewed scientific articles or independent lab engineering data to support your claims.

[texasvfr]

If you really need to add something to flush your system just add some vinegar , nontoxic and not too caustic.

[Grum]

Hi Kris78.

Once you have a clean cooling system, as I said before, go for the Honda Type 2 pre mixed coolant, then you are assured of using the right stuff for your bike. DO NOT COMPROMISE on coolant quality. VFR engines run hot, especially in hot ambient temperatures as would be common in Darwin, also in stop start traffic your cooling fan will be working overtime.

How old is your bike? How many K's has it done?

There is no way known a well maintained VFR with the correct coolant AND concentration level should end up with crap under the radiator cap. Perhaps its been simply topped up with tap water which may be full of minerals causing the crap as well as greatly diluting the coolant qualities.

I would be very concerned that the coolant level was SOOOO LOW!!!! Do you have a leak somewhere? I would be doing a detailed inspection of every water hose and connection, including the hoses under the intake throttle body area.

Such a low coolant level is not a sign of a well maintained bike. Perhaps the radiator cap you are replacing may solve the leakage issue, however its vital you sort out why the coolant is running low.

Best of Luck.

Cheers.

Grum.

[Guest Kris78]

Well new radiator cap fitted today and all issues fixed

Cheap and quick fix

I flushed the system with distilled water and put in that coolant I posted with the new cap and it's all good now

I'm sure that the coolant was low due to the cap letting the coolant pass into the over flow bottle and leak over the ground.

I have been told by Honda that the bike has been serviced when needed. I'd say myself that tap water had been used to top up the cooling system and maybe due to the old owner not being mechanically minded that he did not change the cap or start looking for faults and just topped up the cooling system...

[spud786]

Im probably the only VFR rider that has the least amount of issues with everything from electrics to thermostats and high mileage, I simply use a prestone mixes with anything at a 60%+ range + distilled. Been that way since the bike was new off the floor in its first month.

Now if you allowed the coolant system to degrade, to the point you need a cleaner, that's I factor I've never have to deal with.

[Aimbot9000]

Prestone Radiator Flush + Cleaner is what I used my first coolant change for peace of mind as I had no maintenance records. Dont know if you can get that stuff locally.

[Redbike]

2006A model - How much old coolant should I drain (did it when the bike is cold, on main stand, I drained from water pump and also the front cylinder with open cap, and let it drop)?

I just did it last week. Then I filled up with anti calc water and drained, so I got clear water, not more the green Honda Liquid.

I also washed the reservoir, since it was inside a bit old/green/dirty.

Finally I filled up still in cold state trough the radiator cap + the reservoir till max level with Motocool Expert.

In sum only 3L (the manual said 2.92L+0.9L )!

Then I made an engine warm up with some RPM+5000 peaks.

When I checked the cap was still full and found extra 8mm in reservoir tank too. I also checked: cooler now started at 106C (earlier at 102C)

Was it normal?

Does it mean, I still have 1L old coolant in? Or some anticalc water

[expvet]

When you filled it up with the anti calc water did you run it to temps where the thermostat would open and let it circulate for a while? Also when you opened the 2 drain plugs was the radiator cap off? 

[Redbike]

No. I did it Cold...as Haynes and an other Honda VFR 800 repair books said.

First I simply drained the old coolant opening both drain screws and the radiator cap.

Then I plugged in the drain holes and filled up full with anti calc water.

Then I drained the water through both holes filling some extra water, while the old coolant color changed to transparent water.

Also drained and cleaned the reservoir tank.

Then I drained system complete.

Then I filled up full with new coolant also the reservoir tank.

Then I warmed up till 100C with some throttle pulses.

Later I checked and filled up the radiator cap and the reservoir to max.

Then I warmed up till 100C in 10km.

Later I checked the radiator cap and filled up to top on side stand again.

In sum, I filled in 3L Motocool Expert.

I checked the coolant quality-->-30C, on the bottle it was -37C.

 

Haynes said: new coolant must be replaced in two steps. I did it once after washing with water trough.

2. loop would have gone closer to -37C, but I think  complete draining would be only possible by removing the radiators and coolant pipes...

 

[Lint]

OK, your first step was to drain the old coolant and then reinstall the drain screws and radiator cap. Second step was that you filled it with anticalc water. Did you, at this point, run it enough to open the thermostat? I think you should have, if you did not. My thinking is that you did not give the water a chance to circulate and flush everything out.

 

Also, make sure you "burp" all of the air out. Put your bike on the side stand and remove the radiator cap. Run your bike and occasionally blip the throttle to circulate the coolant and let the air out.