Zero front Brake Pressure | Page 2 | GTAMotorcycle.com

Zero front Brake Pressure

TwistedKestrel

King of GTAM
Site Supporter
The fact that you haven't seen any improvement leads me to think something is wrong. First thought goes to the master, but why would it fail at exactly this time?

Sorry to ask this question: You didn't swap the calipers, did you? I.e. the bleed nipples would be at the bottom instead of the top. Not sure if this is even physically possible in this application, but it would make bleeding difficult
 

Wyled

Well-known member
The fact that you haven't seen any improvement leads me to think something is wrong. First thought goes to the master, but why would it fail at exactly this time?

Sorry to ask this question: You didn't swap the calipers, did you? I.e. the bleed nipples would be at the bottom instead of the top. Not sure if this is even physically possible in this application, but it would make bleeding difficult
I am inclined to also agree. It seems to be the same result everytime even when I did the complete rebleeds. Theres the tiniest but of pressure compared to well, air, but nothing of value at all. And that nothing has changed anything is scaring me.

I didnt change the calipers but i changed the pistons (cleaned them), and replaced the dust seals all of them. Just new lines were added
 

TwistedKestrel

King of GTAM
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Sorry again - by swap I mean accidentally switching the left and right calipers. Are the bleeders on the top side, or the bottom side?
 

ToSlow

Well-known member
Site Supporter
I am inclined to also agree. It seems to be the same result everytime even when I did the complete rebleeds. Theres the tiniest but of pressure compared to well, air, but nothing of value at all. And that nothing has changed anything is scaring me.

I didnt change the calipers but i changed the pistons (cleaned them), and replaced the dust seals all of them. Just new lines were added
i'm wondering if you didn't rip the seal "O-RINGS" when you pushed the pistons back in the calipers. If it was me now riding is done i would pull the caliper back off and take it apart and double check the work
 

GreyGhost

Well-known member
Site Supporter
I've had a braided stainless line that had your symptoms. It turned out to have a hole in the liner but you couldn't see it. Swapping it for a crappy rubber line confirmed the issue was in the "better" part.
 

Wyled

Well-known member
Sorry again - by swap I mean accidentally switching the left and right calipers. Are the bleeders on the top side, or the bottom side?
topside
 

Wyled

Well-known member
i'm wondering if you didn't rip the seal "O-RINGS" when you pushed the pistons back in the calipers. If it was me now riding is done i would pull the caliper back off and take it apart and double check the work
might as well, although there havent been any leaks from the pistons
 

Wyled

Well-known member
I've had a braided stainless line that had your symptoms. It turned out to have a hole in the liner but you couldn't see it. Swapping it for a crappy rubber line confirmed the issue was in the "better" part.
really hope not but. did it leak brake fluid?
 

GreyGhost

Well-known member
Site Supporter
really hope not but. did it leak brake fluid?
Not obviously. I think it may have been wicking through the braid. In that case it was a hydraulic clutch but fundamentally similar. Days of head scratching and trying various options and finally resorted to part swapping to find the issue. Luckily the first part swapped was the winner.
 

bitzz

Well-known member
HMMmmmmmmmmmmmmm
Two weeks and you guys still haven't figured it out. I don't think I would hire any of you to fix my brakes.
Hydraulic disc brakes is a pretty simple circuit, nothing complicated about it.

NO I AM NOT OFFERING ANY SUGGESTIONS
If you don't understand this simple circuit you have NO BUSINESS screwing around with it.
OP: Take the bike, or just the brakes, to someone that knows what they're doing. If you remove the setup and bring it to me, I'll bleed it for you.
 

ToSlow

Well-known member
Site Supporter
HMMmmmmmmmmmmmmm
Two weeks and you guys still haven't figured it out. I don't think I would hire any of you to fix my brakes.
Hydraulic disc brakes is a pretty simple circuit, nothing complicated about it.

NO I AM NOT OFFERING ANY SUGGESTIONS
If you don't understand this simple circuit you have NO BUSINESS screwing around with it.
OP: Take the bike, or just the brakes, to someone that knows what they're doing. If you remove the setup and bring it to me, I'll bleed it for you

hard to see what's going on over the internet, can only work with what you got.
 

Trials

Well-known member
but it is pretty awesome if you can actually help some biker fix their ride from miles away.

Brakes are Easy to fix if they don't work, replace parts.
Hydraulics are as easy to fix as plumbing, replace parts.
Job done, bleed and test ride 🏍️
 

J_F

Well-known member
Site Supporter
HMMmmmmmmmmmmmmm
Two weeks and you guys still haven't figured it out. I don't think I would hire any of you to fix my brakes.
Hydraulic disc brakes is a pretty simple circuit, nothing complicated about it.

NO I AM NOT OFFERING ANY SUGGESTIONS
If you don't understand this simple circuit you have NO BUSINESS screwing around with it.
OP: Take the bike, or just the brakes, to someone that knows what they're doing. If you remove the setup and bring it to me, I'll bleed it for you.
you couldn't afford me, so no worries
 

Mad Mike

Well-known member
Not obviously. I think it may have been wicking through the braid. In that case it was a hydraulic clutch but fundamentally similar. Days of head scratching and trying various options and finally resorted to part swapping to find the issue. Luckily the first part swapped was the winner.
It could also be a herniated line. Rare, but that’s likely what you had. A tear in the pressure layer puts the lining pop thru and expand like a balloon, no leaks but also no pressure. Very hard to see if there is an external braid.

Try returning the old lines to the bike. If they bleed ok, then you have eliminated calipers and master. Swap the braids one at a time bleeding in between to prove the braided lines.
 

Wyled

Well-known member
I should also add I'v used a vacuum pump on them and they still haven't changed
 

Mad Mike

Well-known member

Trials

Well-known member
Can you put your finger between the plates and even feel movement?
even just using a syringe and plastic tube just pushed onto the bleed screw? .... careful that can get messy.
 

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