Bleeding the front brakes

[Scoots]

I need to change the brake fluid on my '89 R100RS. I thought I'd try the "reverse bleeding" method.
Could someone give me a quick rundown of this method? I'm familiar with brake bleeding and did it regularly on my VW Beetles, but never reverse bleeding. I want to make sure I don't screw up!

THANKS

[SteveD]

Tools:
new brake fluid,
dot 4 or 5.1 but not 5.0,
clean 60cc catheter tip syringe,
any syringe 20-60cc,
smooth bore tubing to fit syringe and bleed nipple, 18" or so.
10mm ring wrench,
phillips head screw driver.
old towel

Technique: bike on cs. h'bars tilted to the left so that fluid reservoir is not tilted. wrap the towel around the reservoir so any spillage doesn't reach your paintwork. The wheel needs to stay turned to the left so the reservoir remains level.
Remove reservoir cap (screwdriver). Aspirate and discard the old fluid with any old syringe. Inspect base of reservoir for crud. Wipe clean.
Assemble the filled catheter tip syringe to the tubing, hang the wrench over the left caliper bleed nipple, prime the tubing to expel all air, then attach it to the left bleed nipple.
Open the bleed nipple then slowly push the new fluid in. After a 20-30 ml volume is in, stop and assess the reservoir. Is there more old fluid there? There should be, so aspirate and discard, then repeat until the fluid becomes clean.

Then close the bleed nipple and move to the right caliper, repeat as above...then finish off by putting it all back to how it should be.

I hope that helps but I haven't done it on a mono with the linked calipers, just on a ts with the separated calipers.

[barryh]

I find the fill from the bottom syringe method works well particularly on a completely empty system. If it's only a fluid change I also use the syringe in reverse as a vacuum bleeder to suck fluid out of the bleed nipple. The only issue in both cases is leakage past the nipple threads, either fluid out or air in. I use PTFE tape on the threads only, keeping well away from the sealing cone.

[Major Softie]

I find the fill from the bottom syringe method works well particularly on a completely empty system. If it's only a fluid change I also use the syringe in reverse as a vacuum bleeder to suck fluid out of the bleed nipple. The only issue in both cases is leakage past the nipple threads, either fluid out or air in. I use PTFE tape on the threads only, keeping well away from the sealing cone.

I do the same. Especially on older bikes, somtimes with a little corrosion on the nipple threads, they can leak profusely without taping.

[Scoots]

Thanks guys.
All went well.