Brake Fluid Flushing

. I will attempt flushing the brakes, and anti-freeze only if there is enough time.<<>> having all the tools and replacement items at hand you could be done in a morning easy, a look around the how to section here will be a big help if this is your first attempt.

Use a turkey baster and remove the brake fluid from each reservoir. Fill with new brake fluid. Do this every year and the fluid in the line going to the brake shoes will be diluted with the new fluid every time you apply the brakes. Easy to do and it takes 10 minutes for both reservoirs. Been doing this with Goldwings for 15 years.

Modernman1953 wrote:

Use a turkey baster and remove the brake fluid from each reservoir.  Fill with new brake fluid.  Do this every year and the fluid in the line going to the brake shoes will be diluted with the new fluid every time you apply the brakes.  Easy to do and it takes 10 minutes for both reservoirs.   Been doing this with Goldwings for 15 years.  

?? how does brake fluid " circulate " in a brake system.

The fluid in the reservoir goes down as the brake pads wear. The new fluid will not find it's way to the wheel cylinders. The right way is to open the bleeder while apply the brake. Close the bleeder then release the brake. Keep checking the reservoir and filling as needed. Repeat the process.

Be careful. There are some members that get upset for repeating the same subject.

Just read the service manual, else have the Honda shop do it. Very important to know what you are doing when messing with your brakes.

The fluid in the reservoir goes down as the brake pads wear. The new fluid will not find it's way to the wheel cylinders. <> nor will any crud / moisture be removed. There has to be some reason it's a recommended periodic service.

oldwingguy wrote:

The fluid in the reservoir goes down as the brake pads wear. The new fluid will not find it's way to the wheel cylinders. <> nor will any crud / moisture be removed. There has to be some reason it's a recommended periodic service.

I would drain the reservoir, put new DOT-4 brake fluid, loosen the bleeder, pump and hold the brake handle while loosening the bleeder until the fluid drains into a cup. When the brake handle bottoms out, close the bleeder then release the brake handle. Add more fluid in the reservoir. Start the process all over again until either the fluid changes color or you feel that enough fluid has been emptied into the cup. The amount should include the volume of fluid in the wheel cylinders. Tighten the bleeder.
The service manual should have the recommended procedure.

One man job with a Mity Vac. REMEMBER it's not how much one bleeds it's how one bleeds well, with the Mity Vac. ONLY use enough " draw " to move the fluid, it's not necessary to see how high on the gage one can raise the dial. That and doing it the correct order.

My wife has always been there to assist me with all my past cars and trucks. She will be assisting me with the Swing.

Lucky you.

Molecular diffusion will mean that over some time, all of the fluid will end up the same, so the stuff in the reservoir will pull moisture out of the lines, and new fluid will end up in the lines. If this is done every year, the fluid will be fine forever with no buildup of gunk.

But if you want to get every bit of the old out, then bleed your brakes.

Be sure to get every bit of oil out of your motor every time you change your oil too.... lol

Modernman1953 wrote:

Use a turkey baster and remove the brake fluid from each reservoir.  Fill with new brake fluid.  Do this every year and the fluid in the line going to the brake shoes will be diluted with the new fluid every time you apply the brakes.  Easy to do and it takes 10 minutes for both reservoirs.   Been doing this with Goldwings for 15 years.  

Modernman1953 wrote:

Molecular diffusion will mean that over some time, all of the fluid will end up the same, so the stuff in the reservoir will pull moisture out of the lines, and new fluid will end up in the lines.  If this is done every year, the fluid will be fine forever with no buildup of gunk.  

But if you want to get every bit of the old out, then bleed your brakes.

I was at an independent bike shop and talked to a very experienced old motorcycle mechanic today. I asked him specifically whether it was necessary to completely change the brake fluid and bleed the brakes on my 2006 Silverwing with 7,000 miles. He did not recommend it. He said to do as above, just drain each reservoir with a turkey baster and refill with DOT 4.

Any further evidence for this either way?

I did as he recommended but if a total bleed and replacement is really necessary I’ll take it in to Honda early next month.

My 2 cents worth is that the callipers are at the lowest point of the brake system, and any grunge will tend to accumulate there. Whenever I service the brake fluid I syringe out the reservoir, mop out any residual grunge, then refill with clean fluid. Then attach a bleed hose to the nipple, apply lever pressure and crack the bleeder, close the bleeder, release the lever, then repeat as needed. The old fluid is usually quite dark in colour, and you can usually see when the fresh clean fluid arrives. It may take a few reservoirs full of new fluid to get the old fluid purged.

Terry Smith wrote:

My 2 cents worth is that the callipers are at the lowest point of the brake system, and any grunge will tend to accumulate there. Whenever I service the brake fluid I syringe out the reservoir, mop out any residual grunge, then refill with clean fluid. Then attach a bleed hose to the nipple, apply lever pressure and crack the bleeder, close the bleeder, release the lever, then repeat as needed. The old fluid is usually quite dark in colour, and you can usually see when the fresh clean fluid arrives. It may take a few reservoirs full of new fluid to get the old fluid purged.

The brake fluid was amber but clear. I could easily see the bottom of each reservoir and there was no muck or grunge in the reservoirs themselves fortunately.

I guess I’ll pick up the hose and bleed them next.

I also syringe out the old brake fluid, refill with fresh clean fluid, and bleed the brakes using a Rothewald brake bleeder kit. It's a simple uncomplicated procedure, and as Mr Smith says you can see the old darker fluid changing to the clearer new stuff.

At least then you know the brakes have clean fresh fluid in the reservoir and brake lines and have been bled. Rather than taking the word of some hairy arsed old bike mechanic who's only half done the job on the Service Checklist.

Using a turkey baster instead of a syringe seemed a tad primitive too,

Meldrew wrote:

Using a turkey baster instead of a syringe seemed a tad primitive too,

I watched several videos on replacing the brake fluid and using a metal turkey baster was specifically  mentioned.

https://m.youtube.com/watch?v=U7zwmHeyMgE

I’m a retired foot doctor so I’m quite familiar with syringes, with some in my medicine cabinet, but I found using a metal turkey baster quite satisfactory.

I'm not a retired foot doctor, but I am familiar with using 50ml and 100ml syringes to carry out various maintenance jobs. They're far easier to use than a primitive turkey baster isn't even much good for it's intended culinary purpose. There's far less chance of spilling brake fluid onto paintwork with a syringe too.

I suppose you have to find a use for your turkey baster,  Don't y'all now deep fry your Thanksgiving turkeys outside on the porch instead of using the oven.

They've had to produce YouTube safety videos about the dangers of lowering wet turkeys into hot oil.  I watched Bill Shatner ruining his new loafers in one video when the oil overflowed..  

The only use I've found for a turkey baster is adding or removing coolant from the expansion tank after changing to get the correct level.

Brake fluid is "hygroscopic", it draws moisture from air overtime and degrades, water/moisture is heavier than brake fluid and settles at lowest point in system, brake calipers. It causes corrosion at pistons/bores. Brake fluid does not cycle thru or is consumed by system, strictly gravity feed, brake fluid should never be serviced to full mark, unless new pads are installed, normally level only drops due to pad wear. System should be completely flushed every 3-5 years, regardless of mileage or use.

So then why not replace the DOT 4 brake fluid with DOT 5 which is synthetic and not hydroscopic?

Cosmic_Jumper wrote:

So then why not replace the DOT 4 brake fluid with DOT 5 which is synthetic and not hydroscopic?

Dot 3,4+5.1 are compatible/glycol based all Hygroscopic (refers to a matter's ability to adsorb and absorb water from the surrounding environment), the higher the number, better quality.

Dot 5 silicone fluid is not compatible with any other brake fluid, only way to use in a glycol system is to completely remove/clean any trace of old fluid, as in full disassembly of all components, etc., any trace could diminish brake performance. Nearly impossible on ABS models.
Not worth it, IMO.

My 2012 SW brakes where not serviced in 8yrs/10K miles here in the moisture state, a full caliper clean and seal replacement was the final solution to my occasionally sticking front brake, after several flushes fail to fix it.

I ordered a set of Speed Bleeders to do it right and make bleeding the lines a bit easier:
http://www.speedbleeder.com/index.htm

zrx212 wrote:

My 2012 SW brakes where not serviced in 8yrs/10K miles here in the moisture state, a full caliper clean and seal replacement was the final solution to my occasionally sticking front brake, after several flushes fail to fix it.

I have a bad habit of buying older Honda's from uncaring owners and then working them back to a decently maintained state, so I have had more than my fair share of brake experience. If you are handy, I fully endorse completely stripping the master and callipers for a full inspection.

The calliper pistons can corrode and pit and that damages the outer seals, and causes unwanted binding. The grooves that the seals sit into also get corrosion/dirt build-up, and that squeezes the seals hard onto the pistons, again causing binding. The only fix for that is to disassemble and carefully scrape the groove clean and fit new seals.

I have come across some quite nasty debris in callipers or clutch slaves, which I assume is crystallised brake fluid. No way to get that out without disassembly. There's usually a brown sludge present as well.

One area that often gets overlooked on callipers like the Swing uses are the sliding pins; the callipers have to be able to slide sideways when the pistons extend to pull the back pads onto the disc, and if you don't keep the sliding parts greased (Honda says silicone grease only) they seize and you loose brake power.