Brakes Brake loosing pressure

bad seal on piston? bad crimp on connection? bad or cross threaded nipple on the caliper? bad resivoir cover seal?

this stuff gets expensive to fix/find but once you do.... well you know the rest ;)
 
pagheca said:
They just called me. The bike is ready. There was air in the circuit. Probably it got in when I changed the tube last time, but I wonder why it increased the other day. Does it sound reasonable or could I get the same problem again in your opinion?

Regarding the tubeless conversion, they told me that they can do it even if I buy the tires myself online.
Click to expand...
How are your eyes doing today, are ya doin alright?
 
HumanPerson said:
I just cannot wrap my head around how you would have gotten air in the brake lines from changing a tube lol
Click to expand...
He probably had a pocket of air in the hand-brake reservoir. When he inverted the bike to work on the tire, air bubbled up from the handbrake to the Caliper.

Just a guess, but it feels right.
 
HumanPerson said:
Well thank you mate

Has it cleared up your vision, crisp, and clear now?
I may have to do something in a few years with me eyes

I'm a big scardy cat LOL
Click to expand...

For some obscure reason, I have no fear of doctors, dentists (and dogs... :) ), etc. Only of.. moths and butterflies! :LOL: I always go to medical operations very relaxed and this HELPS a lot because I relax and just get curious about what the hell the surgeon is doing.

I can claim to have "international cataract experience" :cool: because I was diagnosed in Italy, had my left eye operated on in England, and my right eye operated on in Spain :). I can tell you that the first one was a bit annoying because I could see the strong light from the operating table. The second one was a piece of cake: NO pain, no problems (so far). And I started to see more and more a few hours after the surgery. I am almost there, just a bit blurry but focus is OK.
 
pagheca said:
For some obscure reason, I have no fear of doctors, dentists (and dogs... :) ), etc. I always go to medical operations very relaxed and this HELPS a lot because I relax and just get curious about what the hell the surgeon is doing.

I can claim to have "international cataract experience" :cool: because I was diagnosed in Italy, had my left eye operated on in England, and my right eye operated on in Spain :). I can tell you that the first one was a bit annoying because I could see the strong light from the operating table. The second one was a piece of cake: NO pain, no problems (so far). And I started to see more and more a few hours after the surgery. I am almost there, just a bit blurry but focus is OK.
Click to expand...
I wish I had your faith in doctors. My problem is that with knowledge comes the awareness of their mistakes. I scheduled a meeting with an OBGYN who botched a surgery on my (then) wife. I laid out every single mistake he made during the surgery, and even gave him the page numbers from the books in his library (from the bookshelf in his office) which described the correct way to perform the procedure. He retired that day.

I had another doctor who I told him what the problem was (Kidney stone), and he proceeded to remove my appendix. The appendix was not the problem, and I finally peed out the kidney stone a week later. (They symptomology was spot on "textbook" for kidney stone and was incorrect for appendix).

I had another doctor who I clearly told him I had fractured ribs and a collapsing lung; he took blurry X-Rays (overexposed) and could not see the fractures. (Two ribs fractured (broken) in two places, another rib in one place). He sent me home to die. I returned to the hospital an hour later, (even bluer), and insisted on care. They put me in a room overnight on some oxygen (to shut me up). The next morning, they did a portable chest X-Ray, and FINALLY figured out my right lung had fully collapsed, and my Heart had shifted to the right to fill the empty void. This kinked my Aorta (like a garden hose) cutting off blood flow. He gave me a quick shot of versed (Midazolam) and proceeded to cut into my chest (and spread my ribs) to insert several inches of hose connected to a vacuum pump to re-inflate my lung). All of this happened when I was awake (as waiting for an operating theater would have been lethal).

I have an unusual amount of medical knowledge for a non-medical worker. With greater knowledge comes the certainty that too many Doctors are not skilled at their jobs. The first doctor in my story had over 30 years of practice behind him when I forced him out.
 
addertooth said:
I wish I had your faith in doctors. My problem is that with knowledge comes the awareness of their mistakes. I scheduled a meeting with an OBGYN who botched a surgery on my (then) wife. I laid out every single mistake he made during the surgery, and even gave him the page numbers from the books in his library (from the bookshelf in his office) which described the correct way to perform the procedure. He retired that day.

I had another doctor who I told him what the problem was (Kidney stone), and he proceeded to remove my appendix. The appendix was not the problem, and I finally peed out the kidney stone a week later. (They symptomology was spot on "textbook" for kidney stone and was incorrect for appendix).

I had another doctor who I clearly told him I had fractured ribs and a collapsing lung; he took blurry X-Rays (overexposed) and could not see the fractures. (Two ribs fractured (broken) in two places, another rib in one place). He sent me home to die. I returned to the hospital an hour later, (even bluer), and insisted on care. They put me in a room overnight on some oxygen (to shut me up). The next morning, they did a portable chest X-Ray, and FINALLY figured out my right lung had fully collapsed, and my Heart had shifted to the right to fill the empty void. This kinked my Aorta (like a garden hose) cutting off blood flow. He gave me a quick shot of versed (Midazolam) and proceeded to cut into my chest (and spread my ribs) to insert several inches of hose connected to a vacuum pump to re-inflate my lung). All of this happened when I was awake (as waiting for an operating theater would have been lethal).

I have an unusual amount of medical knowledge for a non-medical worker. With greater knowledge comes the certainty that too many Doctors are not skilled at their jobs. The first doctor in my story had over 30 years of practice behind him when I forced him out.
Click to expand...
Jeepers mate!

Well, we're glad yur still here and made it over to us to have these chats :)
 
addertooth said:
I wish I had your faith in doctors. My problem is that with knowledge comes the awareness of their mistakes. I scheduled a meeting with an OBGYN who botched a surgery on my (then) wife. I laid out every single mistake he made during the surgery, and even gave him the page numbers from the books in his library (from the bookshelf in his office) which described the correct way to perform the procedure. He retired that day.

I had another doctor who I told him what the problem was (Kidney stone), and he proceeded to remove my appendix. The appendix was not the problem, and I finally peed out the kidney stone a week later. (They symptomology was spot on "textbook" for kidney stone and was incorrect for appendix).

I had another doctor who I clearly told him I had fractured ribs and a collapsing lung; he took blurry X-Rays (overexposed) and could not see the fractures. (Two ribs fractured (broken) in two places, another rib in one place). He sent me home to die. I returned to the hospital an hour later, (even bluer), and insisted on care. They put me in a room overnight on some oxygen (to shut me up). The next morning, they did a portable chest X-Ray, and FINALLY figured out my right lung had fully collapsed, and my Heart had shifted to the right to fill the empty void. This kinked my Aorta (like a garden hose) cutting off blood flow. He gave me a quick shot of versed (Midazolam) and proceeded to cut into my chest (and spread my ribs) to insert several inches of hose connected to a vacuum pump to re-inflate my lung). All of this happened when I was awake (as waiting for an operating theater would have been lethal).

I have an unusual amount of medical knowledge for a non-medical worker. With greater knowledge comes the certainty that too many Doctors are not skilled at their jobs. The first doctor in my story had over 30 years of practice behind him when I forced him out.
Click to expand...
Hi addertooth,

I'm really sorry to read about all these misadventures of yours and your wife. I fully hear you. I don't think there is a single person (alive or ... dead) who has not had at least a few medical misadventures in his or her life, either for himself or for some relative or friend. I'll spare you my own adventures and those of my friends.

However, mine is not blind faith in doctors. It's that while I was having surgery I was thinking how lucky I was to have happened to be in the only time in human history (long, say, two hundred thousand years), and in one of the few places in the whole world where you have a chance to have such an operation in three hours, go home, and in a few days regain your sight. And all without spending a penny!

Until less than a century ago I would have died at age 22 from severe appendicitis, my wife as a child from nephritis, my mother at age 6 from typhoid-so I wouldn't be here writing these considerations. Instead, I went to a hospital in a little remote island that may not be perfect, may not be error-free, but thanks to so much technology developed over the last century and the competence and skills of a few doctors am here after two days joking about it, and without having experienced any pain.

Doing the divisions comes out to a probability of about one in ten thousand: 100/200,000 * 1/10 (at a rough guess the area of the world where this happens, for free). Had I been born in Africa, or just 100 years ago, the story would have been very different....
 
HumanPerson said:
I just cannot wrap my head around how you would have gotten air in the brake lines from changing a tube lol
Click to expand...
If the caliber piston came out to far while the wheel (rotor) was removed, like maybe the brake lever was squeezed accidentally. And then the piston was pushed back in to mount the wheel it sucked in some air. I've seen this happen when changing out motorcycle wheels.
Click to expand...
 
pagheca said:
Hey guys,

my bike's hydraulic rear disc brake suddenly started losing pressure. There are no visible leaks.

All started when I changed a flat tire a few weeks ago. When I put the wheel back on, I noticed that the brake was a little loose and elastic. Then the other day, while descending a long, steep trail, it suddenly started losing pressure and making a lot of noise. At the end of the ride the lever was touching the handle.

I'm going to take it to the shop, but I'm wondering what the problem may be. Any advice? Thx!
Click to expand...
Did you place your bike upside down when changing your tyre? I found that my brake levers are very spongy afterwards. A trick I learnt is to use rubber bands to pull the levers in overnight. This is also useful if you have a leaking seal (caliper). When was your brake fluid last replaced? The manufacturers recommend every 6 months though I tend to leave it until the brakes start feeling spongy or there's a noticeable reduction in braking. If the fluid is old it'll boil if you using excess braking, especially downhill. When did you last replace your pads/rotors? When you put your wheel back in, did you line it up dead centre, put any spacers back in there correct order.
 
That's true! I put the bike upside down to change the tire. I'm going to pick up the bike from the store tomorrow, so I'll ask them if they changed the fluid. First maintenance ever since I bought it.

Thanks for the suggestion and Merry Christmas to you and everyone on the forum!
 
Hi folks, last question of 2023 for me...

I picked up my ebike yesterday from the shop. The brake seems to work fine, and they also removed an annoying squeak that was coming from the rear suspension. They say the pressure loss, as already suggested here, is due to oil boiling when it warms up. I'm not entirely convinced, but that's ok. This is not my question.

I rather asked them why the Maxxis Assegai cost so much at their shop (over €100 EACH, plus the cost of the conversion to tubeless). The guy replied that there are different Assegai's compounds, some much more expensive than others.

This is not my understanding after some searches over the internet. This document, although very useful, is not completely clear about that. I do not understand if you can combine the various options once you select a particular tire model, or not.

Any hint?

Have a nice end of the current revolution of our beautiful planet around the Sun, and an even nicer beginning of a new one, filled with plenty of funny rides with your loved ebike and friends!

p.s. sorry: I am a nerdish astronomer and cannot forget that a year is just that... :D
 
After writing the above I found that actually the Assegai comes with many options:
The Assegai can be used front and rear for a surefooted feel or as a front paired with a faster rolling rear tire.

  • Dual compound, 3C MaxxTerra, or 3C MaxxGrip options
  • 60 TPI, DoubleDown (2×120 TPI), or Downhill (2×60 TPI) casing options
  • EXO or EXO+ puncture protection options
  • Wide Trail (WT) sizes are optimized for 35mm inner width rims
  • Select specs are Tubeless Ready (TR), confirm in table below
Click to expand...
from https://www.maxxis.com/int/tire/assegai/

So, the situation become much more complicated as I have to find out about all those options before ordering... :rolleyes:
 
pagheca said:
After writing the above I found that actually the Assegai comes with many options:

from https://www.maxxis.com/int/tire/assegai/

So, the situation become much more complicated as I have to find out about all those options before ordering... :rolleyes:
Click to expand...
The best tubeless option is the EXO/TR if I remember correctly. I have a 29x2.50 Assegai on the back of my GG Smash running tubeless and its a splendid tire. Go ahead and spend the big money on the 3C Terra EXO+/TR. Its an absolute top quality tire. Hard to find an experienced singletrack rider that doesn't sing Maxxis' praises. My Assegai holds air forever on tubeless rims.
 
m@Robertson said:
The best tubeless option is the EXO/TR if I remember correctly. I have a 29x2.50 Assegai on the back of my GG Smash running tubeless and its a splendid tire. Go ahead and spend the big money on the 3C Terra EXO+/TR. Its an absolute top quality tire. Hard to find an experienced singletrack rider that doesn't sing Maxxis' praises. My Assegai holds air forever on tubeless rims.
Click to expand...
My brother, we can lead feckin horses to water......gawd dam it ima bit overwhelmed....i need to go back to the drawing board!!!!!!!!!!!!!


Feck!





I'll see ya in the oncoming year bud! ;)

Hugs :cool:
 

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