It really helps if you
understand what is going on in the brake system.
For example - "you got to #3". That is the start of the process for the rear brake circuit using fluid from the rear reservoir. What you did for #1 and #2 was for the circuit operated directly by the front brake lever using fluid from the front brake lever reservoir. The two circuits are independent of each other.
If you have got something in the calipers to stop the pistons being pushed out, then you can do #1 and #2 as a cycle until they feel firm and then cycle round #3 to #7 without going back to #1 and #2 - until you get the brake pads in, the calipers bolted up and you do the final full bleed 1 to 7 after leaving the brake lever tied back and the brake pedal weighted overnight.
Read this - a lot of people have found it very helpful.
A detailed look at the process of getting the air out of the Honda ST1300 brake lines. A sequence of diagrams of the brake circuits, colour coded to show which parts of the system are being accessed when each bleed valve is opened and explanations of where the trouble spots are. These are just...
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As far as the #3 to #7 sequence is concerned - the brake fluid goes in two directions from the brake pedal master cylinder: a) To the rear centre piston. And b) forward to the front centre pistons.
The line to the rear centre piston is easy to bleed - the brake line goes downhill to the caliper and can be filled with fluid very easily. But you cannot feel this at the pedal. until you have all of the air out of that line - the two halves are joined by a double banjo bolt - so they form part of the same circuit.
Then focus on the line going to the rear outer pistons. This line is complicated: it ends at the rear outer pistons - but it goes first to the front centre pistons. It splits on the front right fork leg above the mudguard (at the delay valve). Get the fluid to the front right centre piston first. Then over the front left centre piston.
It is a very short run - acouple of inches - to the inlet port of the SMC. The next bleed valve after that is back up the fork leg, across the mudguard, a flexible 'n' shaped hose to the headstock ond then to the right hand side under the fuel tank - the pcv bleed valve. Once you get fluid coming out of that valve you need to exercise the pcv to get rid of air and old fluid that is lurking in there. If you are not getting a good flow out of that bleed valve, it is worth carefully unscrewing the valve and pumping a few squirts of fluid. I've had gunge shoot out like a cork from that point. Put the bleed vlave back extremely carefully - gently turn it anti-clockwise unti you feel it drop off the start thread and then gently trun it clockwise. Fingers only until you reach the point at which it needs to be tightened.
The SMC needs to be tilted so the fluid is being pushed uphill, but you're not trying to shift the fluid with the SMC, you are trying to clean the bore, and to help eject the old fluid behind inlet port between the piston's two seals. It needs brake pedal pressure to push the fluid past the primary seal
**. The fluid and air from the outlet port goes (eventually) to the PCV bleed valve. You might need help to keep the flow going while you exercise the SMC by having someone to press the brake lever. Get them to watch the reservoir level as well because while you are on the left side of the bike, the reservoir is quickly running out if fluid.
Then its down to the rear outer pistons and the rear most bleed valve.
This isn't a sequence start to end.
It is a cycle. After doing #7, go back to #3. With more fluid throughout the system the pumping becomes easier.
I use a vacuum pump to get the first cycle out of the way, but I hate using it. Its messy. Use the technique described in the manual. Close the valve, pump the pedal / lever a few times. This builds up air pressure. Hold the pedal down or lever in, open the bleed valve and let the air pressure push the fluid through, close the bleed valve as the fluid flow slows down. Repeat.
After leaving overnight with lever tied back - gently release the lever. Push in the front outer pistons a fraction - air will have collected under the reservoir - this helps it through the tiny compensation port. Ditto with the brake pedal and the rear centre piston.
Once the levers are firming up you can start getting rid of trapped bubbles. Flexing hoses above the mudguard, tapping joints. etc.
Chase the air around the rear circuit. Do the rear centre first. Then chase to the front right centre, front left centre, pcv bleed valve, rear outer pistons. (That is slightly different from the sequence above, but you are chasing an imaginary bubble of air to the next bleed valve. That is different from filling the system from scratch.)
Read the pdf file. Watch the video. Study the pictures. None of this made any sense to me from the Honda manual until I decided to write this document. It was only by putting it together and trying to explain it - and researching and discussing with people like
@Igofar and
@Anna'sDad that it started to make sense.
It often takes me 3 or 4 circuits of the sequence #3 to #7 to get the brakes feeling as they should. I've just refurbished my one way bleed valves - so I can leave them attached while I do the rounds. The old hose was getting to tinted and stiff, but a length of windscreen washer hose is a good replacement. I don't know how long it lasts with brake fluid.
** Explanation of operation of master cylinders.
The operation of a hydraulic master cylinder - as used for the front brake lever, rear brake pedal, clutch lever and SMC. Coloured diagrams and explanations. 1 - 'Relaxed' Brake Master Cylinder (ie Brakes are not Applied) The image shows the front master cylinder and the reservoir...
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