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My bike is a 2016, I have flushed the brake fluid each year, last done about 2 weeks ago.

 

The problem: Now my front lever feels squishy - the machine still stops well, but the lever continues to the bar a bit more after the bite of the brakes. I no longer have a solid feel at the lever.

 

My questions are:

  • Has anyone found a good caliper rebuild kit?
  • Or even felt the need to rebuild their calipers yet?
  • Should I be lubing the pistons with brake lube from the dust seal to the edge where they meet the pad's backing?

 

image.png.39bc0847c2385b3e3b2fe60460375ae5.png

 

I'll bleed the brakes again but I doubt that's the problem. Should lube the pivot points too but that wouldn't cause what I'm guessing is called "brake fade" even at low speed. The bike's 2 years old, and wouldn't you know it, the manual recommends to replace the master cylinder internals AND the caliper internals every 2 years. Since I clean my brake pistons off twice a year with a toothbrush and brake cleaner I'm hoping to avoid a caliper rebuild in favor of a master cylinder rebuild... But then if I have to do that I may as well replace the front lines with steel braided, right? And if I do that, I may as well rebuild the calipers...

 

eBay has a few sellers for $25 per caliper which seems kind of expensive - the OEM parts sites are even worse, the diagrams look like they are selling a seals kit per piston. For the pistons themselves, I can only find them from the OEM sites for like $70 a piece which is insane. The master cylinder rebuild kit is only $15 from the OEM sites though. So $15 for the master kit, $25 x 2 for the calipers, and $100 for the steel lines, all plus shipping. Trying not to spend another $200 on my bike if I can help it.

 

Any thoughts?? I'll post how-tos for the things I wrote above!

his face seems pulled and tense
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There should be no reason on a 2016 to have to rebuild the calipers, unless:

  1. you took them apart damaging seals
  2. They actually have dirt and crud on them
  3. You simply want the experiance of reuilding

Either way buy Genuine yamaha parts for it if you want to

 

IMO you did not bleed them out enough and you have air in the or two did not bleed them out correctly

 

Since you are not seeing any brake fluid leaking out from any place lets assume you need to rebleed them getting air out.

 

Make sure you have placed the bladder in correctly for the master cyclinder

 

Questions:

 

  1. Did you dissaemble the calipers?
  2. Did you attempt to clean clean the pistons?
  3. Did you pull push on the pistons?

Fading is a sur esign of air or a leaking system

 

“Laws that forbid the carrying of arms disarm only those who are neither inclined nor determined to commit crimes.” --Thomas Jefferson quoting Cesare Beccaria

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You can definitively tell if your calipers need rebuilding and if they are the cause of your soft lever. 

 

1- if there is fluid seeping around the pistons. Easy peasy.

 

2- With the caliper in your hand, pump the brake lever and watch the piston. You should see if activate then retract slightly. If it's retracting slightly then it's in great shape and functioning as it should. 

 

If you're not losing any fluid then I might be inclined to inspect the brake lines fully for swelling, especially while the brake is activated. You may have a braided portion of the hose that failed and is allowing it to expand greatly. 

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3 minutes ago, r1limited said:

Questions:

  1. Did you disassemble the calipers?
  2. Did you attempt to clean clean the pistons?
  3. Did you pull push on the pistons?

1. Nope

2. Gently, yes. The surface of the pistons had light corrosion on them. They don't leak fluid at the moment and never had to my knowledge.

3. Slowly pressed them out by pumping the lever lightly to get them out of the bore until I could see shiny piston so I could clean the corrosion with a soft tooth brush, mild soap and water, and final spray with brake cleaner before pressing piston back into bore and moving onto next piston. I did it last year in the spring after flushing brake fluid, so I did it again this year once winter "ended". Followed this video:

 

 

6 minutes ago, r1limited said:

There should be no reason on a 2016 to have to rebuild the calipers, unless:

 

Fading is a sur esign of air or a leaking system

 

Yeah I wasn't sure if what I was describing was correctly termed "brake fade" - I don't brake aggressively very often so I know it's not from hot brakes... and it's good to read I shouldn't need to rebuild then. Awful expensive to do that every 2 years if the seals kits cost that much

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Have  you unbolted and raised the right side caliper up over the fender while bleeding with it up high to get rid of that loop of hose over the front fender? 

 

My front brake was mushy as hell when I 1st got the bike. There was a great big air bubble trapped in that high spot over the front wheel. Normal bleeding did nothing until I raised that one caliper up high while fleeing it. 

 

BTW, because of the nature of glycol based brake fluids (Dot 3, 4 and 5.1), the rubber seals and components of brake systems are made of EPDM rubber (same stuff used in rubber roofing systems). EPDM does not like organic solvents and greases, so make sure whatever you use to clean, it specifically states it's OK. 

 

Aerosol brake cleaners will remove graffiti. Not sure I'd want that stuff near a piston seal if any rubber is involved. 

 

 

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is it possible any shine wax/spray or cleaning detergent soak the pads/rotors?? 

 

some pads dont quite work unless used at race speeds, is it possible you put wrong pads on? 

 

these are just other ideas that I thought of... 

2015 fz-07- Hordpower Edition...2015 fj-09- 120whp- Graves Exhaust w/Woolich Race Kit- tuned by 2WDW
 

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You could try the mountainbike method of brake bleed. It requires a "syringe" attached to the BOTTOM nipple ( ie on the caliper). Open the top of the master. Attach the full syringe to the nipple. Open the nipple just enough. Push the fresh fluid UP the lines from the caliper end slowly until you get fresh fluid. You need to keep emptying the top reservoir Repeat on the other side. If you take the calipers off and put the outlet for the line at the highest point it helps.

I think the dirt riders do a similar thing with their bikes but haven't seen it done on a road bike.

Go forth and modify my son...go forth and modify...

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3 hours ago, rick said:

Have  you unbolted and raised the right side caliper up over the fender while bleeding with it up high to get rid of that loop of hose over the front fender? 

 

There was a great big air bubble trapped in that high spot over the front wheel. Normal bleeding did nothing until I raised that one caliper up high while fleeing it. 

Brilliant, this did the trick! The lever is still a little soft but much, much improved. I think I'll try the zip tie thing over night. Thank you!!! I think I can put off a master rebuild until later after all... I thought maybe having it at the end of the maintenance chart was a little much

 

3 hours ago, rick said:

Aerosol brake cleaners will remove graffiti. Not sure I'd want that stuff near a piston seal if any rubber is involved. 

I just use Brakleen, non chlorinated, super quick dry... Drives water out from bores and evaporates quickly. I was told it's safe for brake components but not to get it on the tires... I guess I can't be sure but I've used it all along. 

 

3 hours ago, rick said:

the rubber seals and components of brake systems are made of EPDM rubber. EPDM does not like organic solvents and greases, so make sure whatever you use to clean, it specifically states it's OK. 

So what about Sil-Glyde on the pistons? I read somewhere it helps prevent corrosion but sounds like it might just collect dirt and muck up the bores. I leave them dry as it is but anything to help prevent corrosion would be great 

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32 minutes ago, gregjet said:

You could try the mountainbike method of brake bleed.

Yeah I do the traditional bleed with a syringe on the end of my tubing rather than a bottle, it's easier.. I did try this reverse bleeding procedure and it kind of worked but I realized starting at the brake lever side caliper, doing this is would push any air into the loop over top of the fender... Then how do I get it to the other caliper? Instead, I tried raising the caliper and tapping the line before bleeding it to remove trapped air. I managed to get maybe 10 ml out. 

 

45 minutes ago, norcal616 said:

is it possible any shine wax/spray or cleaning detergent soak the pads/rotors?? 

 

some pads dont quite work unless used at race speeds, is it possible you put wrong pads on? 

Nah I don't put slick stuff anywhere near the brakes, and I do have HH pads but I bedded them in properly thousands of miles ago according to instructions. It was just the brake lever feel not the stopping power that was the issue. Thanks though! 

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" I did try this reverse bleeding procedure and it kind of worked but I realized starting at the brake lever side caliper, doing this is would push any air into the loop over top of the fender.."

That's why whne I bought my HEL brake lines I got the race config ( 2 discrete lines fron the Master to each caliper.) rather than the joining pipe.

Go forth and modify my son...go forth and modify...

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Just push the pistons inward - this will drive the fluid uphill w/o overfilling the system. Keep in mind, there's only so much room up in the master cylinder reservoir. 

 

Dunno what Sil-Glyde is, but of it's silicone, that should not hurt the seals. 

 

One way to avoid that loop over the wheel is to replace the hoses with 2 separate braided lines - one each from the master to each caliper

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3 minutes ago, gregjet said:

That's why whne I bought my HEL brake lines I got the race config ( 2 discrete lines fron the Master to each caliper.) rather than the joining pipe.

That's part of the reason I started the thread asking if a rebuild of the master or the calipers was necessary at this bike's age.. Itching to replace the indirect routing and rubber lines with 2 discrete steel braided lines with new, prettier banjo bolts!

 

5 minutes ago, rick said:

Dunno what Sil-Glyde is, but of it's silicone, that should not hurt the seals. 

Not sure what it's based on but I use it for slide pins and the back of the pads when installing new. 

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37 minutes ago, noodles said:

That's part of the reason I started the thread asking if a rebuild of the master or the calipers was necessary at this bike's age.. Itching to replace the indirect routing and rubber lines with 2 discrete steel braided lines with new, prettier banjo bolts!

 

Not sure what it's based on but I use it for slide pins and the back of the pads when installing new. 

I think with as much air as i had, the pads weren't even bedding properly when I 1st got mine. About 100 miles after that proper bleed, the brakes were way, way better and I've not felt a need for braided lines. 

 

IMO, a switch to HH rated pads would be money better spent. 

 

had a look, that Sil-Glyde is silicone based - where you've used it is perfect. I've never lubed brake pistons or bores (in near 50 years of motorcycling, I've never rebuilt a caliper and my BMW R bikes saw a lot of crappy weather in their combined 100k miles)  Ive  never seen a manual specify it either.

 

I've used this stuff on pins and pivots as well as between the pistons and pad backs https://www.permatex.com/products/lubricants/specialty-lubricants-brakes/permatex-ultra-disc-brake-caliper-lube-4/  

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11 hours ago, noodles said:

1. Nope

2. Gently, yes. The surface of the pistons had light corrosion on them. They don't leak fluid at the moment and never had to my knowledge.

3. Slowly pressed them out by pumping the lever lightly to get them out of the bore until I could see shiny piston so I could clean the corrosion with a soft tooth brush, mild soap and water, and final spray with brake cleaner before pressing piston back into bore and moving onto next piston. I did it last year in the spring after flushing brake fluid, so I did it again this year once winter "ended". Followed this video:

 

 

Yeah I wasn't sure if what I was describing was correctly termed "brake fade" - I don't brake aggressively very often so I know it's not from hot brakes... and it's good to read I shouldn't need to rebuild then. Awful expensive to do that every 2 years if the seals kits cost that much

I'll admit I quit watching the video when he starter rooting around with the toothbrush. Everything you said about cleaning your calipers is the same way I like to do it, but those stiff bristles on a toothbrush can push grit past the dust seal that's around the pistons. That's enough to give you a dragging brake. I prefer yo use a paint brush with long, thin, soft bristles. 

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