wtborrow: pressurized brake bleeding system

[isaac_]

Anyone near marlborough/Central MA have one that I can borrow or does anyone have any recommendations on a system I could buy? I think this is about as close to guaranteeing I don't have any air in my lines. Tired of have squishy brakes on my SV.

[tsorfas]

You don’t need it for real. SV is cake to bleed

[isaac_]

Lever was going to the bar. It was fine at the start of the weekend.


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[tsorfas]

Your issue is not air in the system. Most likely a gasket or something with the line.

[isaac_]

Yea. It’s possible. But I don’t want to leave room for error this time. I’m going to rebuild them and would like to use this method.


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[Tekime]

They sell a vacuum pump & bleeder at Harbor Freight for like $20. Pretty basic but it works. I don't bother with pressure bleeding but always feel like I should. Current brake setup on my SV is tighter than anything I've had before, no pressure bleed but I did take a long time tapping and watching the reservoir as minute air bubbles escaped. Then zip tie the brake lever leave the reservoir a bit loose and let it sit overnight.

I once used a large syringe to pump fresh fluid in from the bottom and it worked awesome... the syringe has since degraded beyond use but this reminds me I want to try that again.

[isaac_]

They sell a vacuum pump & bleeder at Harbor Freight for like $20. Pretty basic but it works. I don't bother with pressure bleeding but always feel like I should. Current brake setup on my SV is tighter than anything I've had before, no pressure bleed but I did take a long time tapping and watching the reservoir as minute air bubbles escaped. Then zip tie the brake lever leave the reservoir a bit loose and let it sit overnight.

I once used a large syringe to pump fresh fluid in from the bottom and it worked awesome... the syringe has since degraded beyond use but this reminds me I want to try that again.

Like a mityvac? I’ve never gotten one to work properly. The syringe method is appealing. I’m going to first work on rebuilding the calipers anyway so I might give this a try if I can’t source what I’m looking for.

[number9]

I once used a large syringe to pump fresh fluid in from the bottom and it worked awesome... the syringe has since degraded beyond use but this reminds me I want to try that again.

KTM specifies this as the way to bleed their clutch slaves, and people use it do their brakes too. It works pretty well!

[Kurlon]

Tractor Supply sells large syringes, FYI. I have a large ultrasonic tank if you want to wander north and dip the calipers in as part of the rebuild.

[Paul_E_D]

Syringe FTW. But PK was talking about the same issue on his SV. He suspects the dust seal on the pucks are the cause and was going to try removing them altogether.

[scottieducati]

After you rebuild them, make sure the pistons are *fully seated* in the caliper when you do your initial bleed. I like to use a hockey puck to keep the pistons all fully seated, this will make your initial bleeding process go a bit quicker.

RE: your issues, as Kurlon states you have a leak somewhere and no manner of bleeding would "cure" it. If you suspect the master, replace it.

[isaac_]

Syringe FTW. But PK was talking about the same issue on his SV. He suspects the dust seal on the pucks are the cause and was going to try removing them altogether.

He and I were talking about this. I inspected the seals and they looked to be in place but I’ll probably take them out as well.

After you rebuild them, make sure the pistons are *fully seated* in the caliper when you do your initial bleed. I like to use a hockey puck to keep the pistons all fully seated, this will make your initial bleeding process go a bit quicker.

RE: your issues, as Kurlon states you have a leak somewhere and no manner of bleeding would "cure" it. If you suspect the master, replace it.

Literally brand new brembo out of the box.

[scottieducati]

Then you’re looking at a piston seal or bleed nipple seal. I assume you bled calipers first then bled the master? If it’s Brembo it’s gotta have a bleed nipple there.

FWIW faux Brembo stuff is out there...


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[isaac_]

Then you’re looking at a piston seal or bleed nipple seal. I assume you bled calipers first then bled the master? If it’s Brembo it’s gotta have a bleed nipple there.

FWIW faux Brembo stuff is out there...


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Calipers first, then MC. That’s been my routine.

Bleed nipple seal?

[Paul_E_D]

Once the system is primed (has a little pressure) Always bleed toward the master. Take the caliper off and push the pucks in to force the air to the top of the system. It you get the master to be the high point, no need to bleed twice or even crack the bleeders. You are simply getting air out, not pushing fluid through. Too much chance of introducing more air by cracking the bleeders.

[scottieducati]

And to clarify when I said I use a puck to hold this caliper pistons back, I mean a hockey puck in the caliper, w/ pads removed. Will help you seat both sides without one moving on you.

[nhbubba]

Tractor Supply sells large syringes, FYI.

They do? Their store staff told me they don't.. and gave me a lot of very dirty looks for even asking for such a thing.

Amazon order history says I bought this : Yobett Large 150ml Plastic Syringe + 120cm (47in) handy plastic tubing: Amazon.com: Industrial & Scientific

Works slick as can be. I use it all the time. Pop a small zip-tie on the line over the banjo to hold it on or it will pop off and spray fluid everywhere. Ask me how I know..

[Kurlon]

The 12 or so I've got in my various bins all came from Tractor Supply.

Producer's Pride 60cc Syringe with Catheter Tip at Tractor Supply Co.

[RyanNicholson]

Yea it sounds like a seal issue to me... since the conversation went to methods of flushing....

I recently got one of these: QSICISL Hand Held Vacuum Pump Brake Pump Tester Set Vacuum Gauge and Brake Bleeder Kit for Automotive with Adapters Case Metal handle - - Amazon.com

It works great on my bike, and for $20 I can't complain. Build quality was impressive for the price and having the case was appealing so it isn't 40 pieces of bullshit floating around a tool box like the last mityvac type thing I had.

The syringe approach is interesting though, with the ability to maybe shake out trapped air if you run into that issue.

PS: The fact that my Amazon link goes to a different (and out of stock) product on Walmart.com is annoying.

[PeaPod]

I have the same problem Isaac. As far as I know I have had it ever since I put a Brembo (RCS) on my bike as well. I don't remember having the issue with an Accossato that I had on there before. Like yours, I pretty much last one weekend and the lever goes to the bar. I get home and take the caliper off one side at a time, remove the pads, push the pistons out, then all the way back in, replace, and pump up the line. Do the same to the other side and then my lever is nice and strong.

I have cleaned the brakes in full by removing the calipers. I have rebuilt the calipers with new rubber. I have replaced the master bleed valve with a speed bleeder. None of this has resolved my issue. I am planning on buying another Accossato over the winter.

[02redhawk]

Did you replace the crush washer on the caliper?

[isaac_]

Did you replace the crush washer on the caliper?

Didn’t even touch the caliper ones. I did at the MC. But this reminds me I need crush washers. Gone to a few stores now and they’re giving me weird looks, “what’s a crush washer?” This was at an auto store...

[02redhawk]

I can just hear your answer "It' a 5 cent critical part of the break system".

[scubasteveRR]

I can just hear your answer "It' a 5 cent critical part of the break system".

break system??? you mean BRAKE system. i know it's a homophone homonym, but you should really learn the difference.

[02redhawk]

You can understand why I was one of the 1st buyers of the original Gramatic ptrogram.