Simplified brake bleeding - Conventional method

[Rolando]

After some years not bleeding brakes or clutch I read up on the 30+ page illustrated routine to bleed my ST1300 brakes in the Articles section above and was figuring it was best to stick to my "if it's not broke, don't fix it" policy for a few more years.

After some consideration I decided to apply my cooking philosophy: Simplify. (I tend to measure and put together all ingredients, but leave out as much of the procedure as possible. Things come out quite well usually, but much easier.)

I bleed the clutch using a clear tube, wrench, soda bottle and the help of my wife in the conventional "open, press, close" sequence where you let the bleed screw nipple open 1/4 turn or less, press the lever or pedal full down, close the nipple srew, release lever or pedal and repeat.

Did this with each of the nipples following the indicated sequence, except I left out the proportional control valve, because that way you only have to remove a single right hand side cover to get to the rear reservoir.

Bleeding procedure sequence:
1. Left front caliper. Outer (top) bleeder. Fed from front reservoir.
2. Right front caliper. Outer (top) bleeder. Fed from front reservoir.
3. Proportional control valve. Left front caliper with secondary rear master cylinder must be tipped. Fed from rear reservoir
4. Rear caliper. Center (forward) bleeder. Fed from rear reservoir.
5. Right front caliper. Center (lower) bleeder. Fed from rear reservoir.
6. Left front caliper. Center (lower) bleeder. Fed from rear reservoir. After re-installing from step three above.
7. Rear caliper. Outer (back) bleeder. Fed from rear reservoir.

As indicated, never did the (3) Proportional control valve and never removed any caliper to tilt in any way.

I'm wondering if experts here haved a knowledgeable opinion on how detrimental this simplified procedure could be to adequate or sufficient brake bleeding.

In the end I got clear fluid and no bubbles at all from all nipples.

Seems to me maybe the proportional portion of the liquid and tubes might have been cleared mostly also.

I do wonder if the caliper tilting is also terrible essential.

Anyway, this is an invitation for debate from those trully knowledgeable here.

Thanks.

Happy riding.

 

[dduelin]

A glance at the left front caliper reveals that the bore of the secondary master cylinder is higher than both the feed hose to the caliper and the hose that sends pressurized brake fluid to the rear caliper via the proportioning valve. Bleeding the LF caliper in place (without tilting) ensures moisture or air trapped in the SMC remains inside the bore of the SMC cylinder. This contributes to "pedal drop" or a brake pedal that drops slightly or has a soft feel after the hand lever is released and to corrosion that eventually disables the link between front lever and rear brake at the least and overheats or locks up the rear brake at worst. It is impossible to properly bleed the slave cylinder on the LF caliper without tilting it above horizontal so bubbles can escape.

 

[ReSTored]

Process sounds OK. Spare the spouse and get speed bleeders. They make the job so much easier. You can do the 3 calipers and the clutch in 20-25 minutes.

 

[Jrnyer]

The very first time I did a complete brake bleed, I didn't get enough fluid pumped from the Proportional control valve, and had the soft rear brake pedal syndrome. But, I didn't realize this until a few day later. So off came the right side tupperware, and did another complete bleed, this time making sure the PCV was completely bleed. Lesson learned.

 

[Who Dey]

Interesting. My 03ST1300ABS seems to have a soft rear brake when first applied, but if I release and press again it firms up. Maybe an improper bleed on the PCV caused this. But, I do not know if the brakes have ever been bled? Had 1630 miles on it when I got it? Hoping to get to INTECH and learn how.


Who Dey

 

[STreaker]

Good timing on this thread; today I replaced my stock bleeders with Speed Bleeders, and what a difference! The brakes now feel like I have steel lines. I've used a suction device before and it worked well, but the difference to that and Speed Bleeders is night and day. Its one of the best and inexpensive farkles you can buy.

 

[Scooter]

Good timing on this thread; today I replaced my stock bleeders with Speed Bleeders, and what a difference! The brakes now feel like I have steel lines. I've used a suction device before and it worked well, but the difference to that and Speed Bleeders is night and day. Its one of the best and inexpensive farkles you can buy.

Jon, just for clarification, what did you use as a suction device before, Mityvac or equivalent???

 

[STreaker]

Jon, just for clarification, what did you use as a suction device before, Mityvac or equivalent???

It was a Mity Vac device purchased at Harbor Freight Tools. The device worked great at first, then the seal failed so I lost suction. At that point, I heard enough good about Speed Bleeders so I tried it. I ran alot of brake fluid through my lines, because new brake fluid is useless if it sits in a can instead of your resevoir.

 

[Fortunet 1]

Good timing on this thread; today I replaced my stock bleeders with Speed Bleeders, and what a difference! The brakes now feel like I have steel lines. I've used a suction device before and it worked well, but the difference to that and Speed Bleeders is night and day. Its one of the best and inexpensive farkles you can buy.

I used an automotive suction pump to bleed all locations using tilt method on left caliper and sequence followed exactly in thread. The pump up device was easy to use and
resulted in noticeably better brake action (and clutch) when completed. Not sure what "speed bleeders" are...or if they would have made this easy job any easier.
Fill me in what they are and maybe a thread with photos. Happy with the fluid my fluid change. Glad I went through the procedure, while the platics were off.

 

[Rolando]

Well, it's great to see this thread got us all to thinking about this.

One reason against suction seems to be that it would pull air into the system if there were any place it could be sucked in from. Conventional pumping pushes the fluid out. However, when you open the nipple, air can be sucked in, unless you get it open just enough to let fluid and bubbles out, but not let more air in through the nipple threads. (About 1/8 turn it seems.) But since you are pumping out, air does not go into the tubes in any case. (There is a system that pushes fluid in from the nipples to the reservoir which seems logical, since bubbles tend to go up. Haven't tried it.)

The most knowledgeable response here seems to me to be the one explaining the need to tilt the left caliper to get the bubbles possibly traped there out. However, from what I can see, strangely enough, the pressure on the fluid does push publes out of the system, even when the fluid is flowing down. I would imagine it would do aproximately the same at the caliper. If bubbles can be made to go down, they can probable be made to leave the system whatever the position of the tubes or caliper. Especially considering most of us run quite a lot of clean fluid through the system on each purge. (I emptied the reservoir at least twice for each nipple.) In practice this seems to be related to pressing the lever or pedal and repeating the sequence relatively quickly. I can see the bubbles returning up the clear tube if I linger too much, but can see them pushed down into the soda bottle if I repeat the sequence at a good rythm.

Another very usefull tip from your contibutions is about pumping and squishiness: If you pump several times the pedal or lever and it gets harder, there are bubbles in the system. This seems a very usefull tip.

In my case the brake lever and pedal seem quite stiff still and were pretty stiff to start. Now the fluid is very clean and through the procedure it was clear how it was being cleaned out and I think even a few bubbles emerged, but can't be sure if they were from the nipple threads.

Now what I need to do is plan another 3000km tour somewhere, mabe Chiapas.

Thanks to all for your comments.

Take care.

 

[STreaker]

I'm glad to read you had a very good response to suction pump, which is the intended result. Speed Bleeders are replacement brake bleeders with a one way valve built in to allow fluid out, but no air in. It simplifies the procedure; once installed all you need is a plastic drain pipe for future bleeds.

If suction device works well for you, stick with it. Cheers, STreaker

 

[dduelin]

If you look at the left front caliper and imagine the hollow section that is the bore of the secondary master cylinder you should be able to see that it is very unlikely that pushing hydraulic fluid down with pressure, or suctioning it out with vacuum, can remove air trapped in the bore. Fluid is coming in and going out across the bottom of the hollow section and the bore tilts up so fluid comes in one hole and out the other with no way for air bubbles above the openings to escape. If there was an outlet at the top of the bore the bubbles and accumulated moisture would travel right on out when bled. This is why Honda specifies the removal and tilting procedure.

The LBS system does have some added complexity compared to independent front/rear systems and some owners report having to repair or replace the secondary master cylinder due to sticking from corrosion well before normal wear would seem to require it.

Regarding pulling air bubbles in through leaking bleeders if you choose to use a vacuum pump - taping the threaded section of the bleeders with teflon tape seals the bleeder threads and prevents air entry. You only have to do it the first time.

Whatever shortcuts you take and still have a firm hand lever and foot brake......hey, it's all good.

 

[Rolando]

Very clear. Evidently this must be taken into account. My clutch and brakes are so responsive and high and not at all squishy that on this occasion at least in my bikes case it seems maybe there were no bubbles. Next time I must do the whole procedure to prevent this rusting and all. Many thanks.

 

[Rolando]

I put everything together in a document attached in pdf format. Hope it is of help.

It seems there may be incorrect information, especially regarding which pivots are fed from the rear brake fluid deposit, although I copied indications from the site. If knowledgeable persons here could check the correct pivot/deposit combination in each case, I can make any corrections.

I did install speed bleeders and they work great.

Thanks to all for your valuable help.

2011-12-18: Step 4 corrected and indications for simplified bleeding at proportional control valve PCV added, as indicated by Dave (ddduelin). Many thanks.

 

[dduelin]

I gave it a only quick glance but I think it is incorrect to show the front brake reservoir supplies the rear center piston as shown in Step 4. The center rear gets fluid directly from the rear master cylinder reservoir.

A member here, Igofar, has found that you can move the right side middle cowl out just far enough to bleed the PCV (proportional control valve) without having to remove the middle cowl and associated fairing parts. I tried this the last fluid flush and found that I could follow Igofar's lead and save about 30-45 minutes by removing fasteners that hold the cowl in place and gently pulling it out at the rear edge then slipping a piece of wood in place to hold the middle out about 2 inches right over the PCV.

 

[Northern Dancer]

I looked at the PDF -- Thanks, it is helpful.
I noticed the Front and Rear Modulators used with ABS -- do they have brake fluid in them and if so how are they bled.

Thanks,

Ron

 

[RaYzerman]

Process sound OK. Spare the spouse and get speed bleeders. They make the job so much easier. You can do the 3 calipers and the clutch in 20-25 minutes.

I'd have to agree with you now... after years of denial about Speed Bleeders, and reading about all the issues with vacuum systems, and after always using teflon tape on my bleeders and sometimes needing a helper..... I tried Speed Bleeders. Total convert, never go back now. However, I didn't get the stainless ones, so resolve to pump a little fluid through at least once a year to keep them "lubed". Note, they come with sealer on the threads. If I replace them, I'll go stainless for the extra money. Love that nice silicone hose that they sell too.

 

[jfheath]

Useful docs !

I notice that both sets of instructions (the Original Post and the pdf version) show the same sequence - but there is a slight variation between these steps and what is described in my Honda Workshop Manual which says:

1)Left Front Outer
2)Right Front Outer
3)Prop Control Valve (Tilt 0-15 degrees)
4)Rear Outer
5)Right Front Centre
6)Left Front Centre
7)Rear Centre.
ie steps 4 and 7 are the opposite way round. Whether this makes any difference or not, I don't know.

(Note however that this is a UK version. Don't know if that affects things.)

 

[Diamond Dave]

Does anyone know if air in the brake system could cause the rear brake to stick? The service manager at Honda told me "no way."

 

[Mellow]

Does anyone know if air in the brake system could cause the rear brake to stick? The service manager at Honda told me "no way."

My first thought was yes.. .but usually, when you have air in the system it feel spongy and sometimes like there's no fluid at all... I think I replied in another thread that it would cause sticking but the more I think about it, I'm not sure. I think air is more likely to cause no pressure or loss of maximum braking pressure rather than sticking.... I'll let those that are more knowledgeable reply.