Article [13] ST1300 - Brake Maintenance - Getting all the air out of the brake system

[MidLife]

Maybe with professional equipment. I wouldn't know, I have never tried.

Yes. Or "semi-professional", but not a hand pump.

About 20 years ago, we had a local dealer doing a fairly decent purging job (better than others) using a vacuum method with an "octopus" hydraulic harness connected to the bleeders. There was a post once by somebody mentioning something similar.

Last mechanic on my 03 was great at purging and I thought he was using a "pumping" method as his compressor was running while purging. But it was a compressed air operated vacuum pump. Worked great (he retired unfortunately, although he was only 72).

Could have been using something like this.

 

[Igofar]

I have done several tech events and allowed professional trained mechanics to use their vacuum pumps first, and while the bikes owners thought the brakes felt great afterwards, I was always able to remove quite a bit more air out of the system, and firm the levers up a lot more after using a simple check valve.
Vacuum pumps are used for speed and not the most efficient.
Bottom line, it’s the mechanic behind the tool, not the tool itself.
Those using vacuums think and believe they are the best and are happy with the results….until they are shown by someone else that there may be a better way.

 

[Andrew Shadow]

In my opinion expecting a vacuum pump alone to completely rid a complicated hydraulic system of all air is misguided and a misuse of the vacuum pump on the part of the user. It is not the fault of the vacuum pump if it is being used for a purpose that it is not particularly good at. That does not diminish the value of the vacuum pump however. They are excellent tools for moving high volumes of fluid quickly and easily through the system when that is necessary. That can be for the purpose of draining a system, refilling a system, or flushing a system. That is primarily what I think that they should be used for. In addition to using a tool, knowing what tool to use when is also part of the process. Knowing the limitations of the tools being used is another part of that process. Making poor choices anywhere in that process reflects poorly on the person making the choice, not on the tool. As common as it is the old adage the right tool for the job is not just an adage.

 

[Sadlsor]

As common as it is the old adage the right tool for the job is not just an adage.

This is true.
What's not included in that truism, is there are times when to complete a job correctly, more than one tool *may* be required.
Yay!
And who couldn't use another tool?

 

[MidLife]

Those using vacuums think and believe they are the best and are happy with the results….until they are shown by someone else that there may be a better way.

A better way to be happy with the results....?

 

[MidLife]

In my opinion expecting a vacuum pump alone to completely rid a complicated hydraulic system of all air is misguided and a misuse of the vacuum pump on the part of the user.

Maybe. But works well if you know how to use it. Results I was happy with (which is of course still far from nirvanic euphoria from a Igofarded bleed).

 

[Igofar]

Pick a weekend and ride over to Arizona and I will bleed your brakes for you, and if they are not better than when you did them with your method, it’s free.
And, I’ve always got have a dozen MP check valves in the tool box if you want to learn how to do it much easier, with less mess, and nothing to clean up afterwards.
What have you got to loose?

 

[MidLife]

Pick a weekend and ride over to Arizona and I will bleed your brakes for you, and if they are not better than when you did them with your method, it’s free.
And, I’ve always got have a dozen MP check valves in the tool box if you want to learn how to do it much easier, with less mess, and nothing to clean up afterwards.
What have you got to loose?

Not my method. Never used Vacuum on the ST myself. MP only.

The old now retired mechanic was the one using vacuum (no hand activated pump, but air pressure operated vacuum pump with continuous sustained vacuum). And so was a local dealer way back then when they were still selling STs.

I am sure I'd be elated with an Igofar supervised bleed. My own bleeds don't feel too bad either....but start feeling mushy 500 miles down the road. Not so with the mechanic's bleeds.

The fluid you start with can also make a difference as there is a range on allowable air in solution. If you are unlucky and start with air on top of the range, brakes that are rock solid at sea level can turn scary mushy over a 14er (same with clutch). And solid again once back at sea level.

Along these lines, an AZ bleed at close to 3000 ft is bound to feel pretty good at my sea level.....

People who really care will syringe degas the fluid before injecting into the master reservoir (just pouring from the container can entrain more air). Top racing will pull a vacuum on their fluid prior use to reduce dissolved air and moisture. There are reasons why vacuum makes sense.

I truly appreciate your offer as we all know there is no better bleed than an Igofar bleed. But that would be the difference between being very happy with the brakes and being very very happy with the brakes; Reaching the point of diminishing returns...while there are other things needing close attention on the bike.