Vacuum Brake Bleeder Recommendation

[tcp71]

I have a mitivac handheld like shown above. I have a compressor run vacuum bleeder. I have a Schwaben pressure bleeder. If i have the right adapter for the reservior, the pressure bleeder is the best. Second is the vacuum bleeder. Just apply some grease around the nipple and control the flow by keeping a wrench on the nipple and opening it just enough to flow fluid out. close it and refill the reservior as needed. The mitivac is useful, but takes a lot of squeezing to keep the vacuum going.

When I bleed mountain bike brakes, the procedure for shimano brakes is to use a screw-on bowl on top of the master cylinder and push fluid into it from the caliper nipple with a syringe. There is a further procedure where you are supposed to squeeze the lever and flow it back down to the caliper, but I've never needed to do that. Avid brakes require a syringe on both sides (caliper and master cylinder) and you basically flow fluid back and forth with any air ending up in the top of the chamber by the plunger.

I would try the syringe method on the motorcycle to backflow from the caliper to the master cylinder reservior. Just do it slowly, keep the wrench on the nipple and close it every few CC's worth of fluid to suck the extra out of the MC reservior by the lever.

 

[TacoFergie]

Take this for what it's worth, but a soft hand lever may be a function of the masters plunger diameter for that particular bike. Some manufacturers use small diameter masters, which give low hand effort to brake, but the lever feel is spongy. Another thing that can lead to a spongy feel is if the caliper pistons are parking too far away from the disc. Pumping up the master and tying the lever to the bars for a day sometimes helps, by allowing the piston to creep closer. This will be particularly problematic is there is corrosion in the system, and the pistons don't move freely.

I think there is a little bit the soft initial application built into the master cylinder piston travel, but it it travels enough to touch my pinky and right ring finger when 2 finger braking on the initial pull. You have me wondering about the calipers now and if they may be returning further than expected. One thing I do notice is on really hot days with the bike in the sun for a while the lever feels better, like it's putting a little head pressure on the reservoir maybe?

 

[TacoFergie]

I have a mitivac handheld like shown above. I have a compressor run vacuum bleeder. I have a Schwaben pressure bleeder. If i have the right adapter for the reservior, the pressure bleeder is the best. Second is the vacuum bleeder. Just apply some grease around the nipple and control the flow by keeping a wrench on the nipple and opening it just enough to flow fluid out. close it and refill the reservior as needed. The mitivac is useful, but takes a lot of squeezing to keep the vacuum going.

When I bleed mountain bike brakes, the procedure for shimano brakes is to use a screw-on bowl on top of the master cylinder and push fluid into it from the caliper nipple with a syringe. There is a further procedure where you are supposed to squeeze the lever and flow it back down to the caliper, but I've never needed to do that. Avid brakes require a syringe on both sides (caliper and master cylinder) and you basically flow fluid back and forth with any air ending up in the top of the chamber by the plunger.

I would try the syringe method on the motorcycle to backflow from the caliper to the master cylinder reservior. Just do it slowly, keep the wrench on the nipple and close it every few CC's worth of fluid to suck the extra out of the MC reservior by the lever.

We'll see how this reverse bleeding goes and I might end up in this spot eventually. I do like to have multiple options for tools and different applications though. So a pressure bleeder may be in my future regardless.