Coolant replacement and clutch bleeding tips

Here's a couple of quick tips. I don't know if these things have been mentioned elsewhere, likely they have, but I'm gonna add them anyway. This was done on a 5th gen.

1. If you've removed the clutch slave cylinder or for any other reason need to bleed the clutch. (I replaced the sprocket and the clutch slave cylinder had to come off, it fell apart when I took it off.)
Most of us have bled brakes or hydraulic clutches before, I have many many times but for some reason the old "open, pull, close, release" wasn't working after an hour of frustration. I pulled the slave cylinder back off the bike to inspect it and see if anything was wrong. I depressed the slave cylinder plunger by hand and low and behold, bubbles started popping up in the reservoir!! All the bleeding I'd done to that point had not moved the air pocket right below the master cylinder!! With the reservoir full, one hand on the clutch lever and one hand holding the plunger in the slave cylinder I pulled the lever which moved the plunger against my fingers, then pushed the plunger back in. After doing this several times there were no more air bubbles popping up in the reservoir and bleeding the rest of the way normally took a whole 5 minutes. Now the clutch feels perfect.

2. Replacing the coolant.
I fully drained the cooling system and filled it with fresh coolant. (I had also done some other stuff) When everything was back together I fired up the bike and it ran just like it should for maybe 30 seconds then the RPM started to climb. I'd never seen the bike idle higher than 2000rpm before, so when it reached about 3500 rpm I hit the kill switch. I nervously inspected everything I had worked on, was it something with the throttle cables? maybe something to do with having pulled the entire clutch system out? I was nervous but couldn't find anything out of place so I started the up the bike with my thumb poised over the kill switch, watched while the engine climbed to just under 4000rpm and sat there. Running perfectly, just sitting at 4000rpm. Weird. After about 30 seconds the rpm began to drop, came down to normal and everything was just as it should be. What the F^$@. The conclusion I've come to is that the ECU on the bike (computer) is able to sense when there is an air bubble in the system, possibly via contradicting data from temp sensors, and one of the ways to deal with air bubbles is to, well, hold the engine at a raised rpm for a minute or two.
So the bike found and fixed a problem before I could figure out there even was a problem! It's a strange sensation to realize your bike is smarter than you...

I'm NOT absolutely possitive that my conclusion for the higher rpm after coolant change is correct. Hopefully someone can confirm or deny that theory, but at least others can be forewarned of this odd behavior and won't have to fear like I did that their bike is about to blow up!

 

Coolant.

Wide large volume pan.
Narow long funnel
2 gallons of distilled watter
coolant

The collant change is messy. You need to take both lower farings.
best if you have a center stand. Teh reason I said distilled water and other will jsut use a garden hose is that the aluminum in these bikes is fragile and In my own opinion keep the scale that is most city or well water out of the engine.

DO not use a coolant that says universal. Most likely it will have silicate (sand) in it. This can eat your impeller on your watter pump. Just go get 4 bottles of honda stuff from your dealer. It is my nderstanding htat Hond coolant products do not use silicate so you can use the car stuff as well. Also Peak makes a HOAT certified coolant that also does not have silicate.
ME... Ilay it safe and buy the honda stuff from my dealer. After all, the money you are saving by doing it yourself is not on the product but on the labor from the dealer. Also, the peace of mind know it was actualy done.

I knwo the 6th Gens have overflo/burp tank on them and that shoudl take care of any air bubbles you get in the system . to keep air to a minimum try and run the bike up to operating temp with the fill cap off. put the cap on then reve the engine a bit. Kill the engine and pop the cap. you may get some air bubbles there. Also by doing this you will see if you need to ad anymore coolant.

A couple of rides after you perform your fill check the over flow tank to see if you need to add anymore.

You will need some old mik bottles plus the distilled water bottles to get rid of the old coolant and flush water.

There may be lots of better ways but this is what I found on my bike.

Good luck.

 

I too am looking for tips on bleading my clutch as well as my linked brake system. After my last bill for this I need to do this myself.

 

Spooky...

I top off the coolant res and rad, lean the bike back and forth a little, start up the bike with the cap off, when the temp gauge starts to move, top off again, hold a rag over the radiator cap fitting and rev bike up to 3K for a few seconds once or twice, final top off and instal rad cap. Allow it to run and verify the cooling fan's operational, take it for a ride, let it cool off and top off coolant reservoir tank if necessary.

 

Took apart slave cylinder and master cylinder to clean.
Once assembled, used the press clutch lever several times, hold in, open and close bleed valve method starting with an empty system.
Within 15 minutes and about 10 iterations, fresh oil was coming out the bleed valve with no air bubles, but had no pressure on the lever.
Finally read a trick somewhere. With a sprot bike, the master cylinder points up, so air stays trapped in the master cylinder and it does not prime and build enough pressure. Problem is not at the slave cylinder.
I turned the handbars right and tilted the bike opposide to side stand side a couple of inch to get the master cylinder to point down.
pressed teh lever and air bubbles came out in the oil reservoir.
Within 5-6 activations of the clutch lever, I had pressure and clutch working fine

 

Invest in a Mighty Vac MityVac MV8020 Brake Bleeding Kit

The clutch is easy enough (I haven't done the linked brakes yet).

1. You pull the cover off the master cylinder (*TIP* if you turn the handlebars fully to the right, the master cylinder sits much closer to level).

2. Top off with dot 4 fluid only.

3. remove the rubber cap from the bleed valve at the clutch slave cylinder (left side, attached to the front sprocket cover).

4. Have a 10mm open-end wrench on the bleed valve, and set up the Mityvac with the correct sized tubing or connector over the nipple.

5. begin to pump as you open the bleed valve, keep an eye on the level in the master cylinder, you don't want to let it get low and suck air.

6. Keep topping the master cylinder. *NOTE* since it is a vacuum it will continue to drain the system after you stop pumping, so keep an eye out.

7. Repeat the pumping and topping off until you start seeing nice, clean fluid coming out of the system and into the Mityvac's catch cup.

8. close the bleed valve, and replace the rubber cover.

9. Replace the rubber bladder, plastic baffle, and cover on the master cylinder, and screw it down.

Enjoy your fresh clutch! :smile:

Brakes are basically the same, but there are multiple bleed points, and I think you need to use the vac at each of them (not sure, have to check the manual) to make sure you get all the old fluid out. ...but the process is the same.

Good luck.

 

Thanks this gives me confidence to proceed with brakes as well. Auto Zone has a bleeder pump for $29. My pocket can't handle dealer $90 labor cost so I really appricate all these helpful hints and instructions. reading the manuals makes some of this seem near impossible or at least complecated.
At just over 30K miles (98 5th gen) I have so far changed oil and filter, coolant and cleaned the overflow reservior. Brake pads appear good but the fluid in both clutch and brake systems needs attention.
Question? How long is a used bottle of brake fluied good for, (synthetic)? I've had it for over a year does it deteriate once opened?
Looks like I have to remove the rear wheel to get to the two bleed valves on the rear brake. Yes?
Appriciate any observations or instruction
Garr

 

Do yourself a favor and buy a new DOT4 bottle of brake fluid if it's been open for a year. The fluid is designed to capture moisture and even with the bottle open and the lid on it will pull moisture from the air and will be pre-contaminated before you use it. It only costs about $8 buck at the dealer. I always use Honda specific fluids, just because Honda made it. The pump system works great and is the best bet. If you can remove the majority of the bad fluid from the master and replace it with new you will have more good fluid running throug the system before you get the old stuff out. Good luck, Nick

 

I did just as you suggested as well as picking up a Mityvac at Pep Boys and went through the Clutch, Brakes front and back with no glitches to speak of, (tapped a couple of banjo bolts to release some trapped air otherwise all went well.
Felt like a real Mechanic so went on to do the Oil and filter and new Coolant. I used K&N air cleaner kit on the OEM Honda air filter as well. This bike runs and shifts better than ever, even stops better as well.

Now that I have your attention let me run this by you...Many of the rubber body work connectors with the brass threads inside that you attach the body work together with seem to be drying out and are in need of replacement. Do you know of where one can get a bag of them for less than a dealer wants (couple of bucks each for crying out loud)?

Thanks much for responding.

Bless your day.

Garr