Zero front Brake Pressure | GTAMotorcycle.com

Zero front Brake Pressure

Wyled

Well-known member
I have a 2010 GSX-R 750 that I bought last year with 11k KMs on it. Right now it has 11500

Before that, brakes were great but I wanted to get new lines and decided to change the pads and seals as well. I've flushed brakes before and replaced lines before.
So, changing the pads and seals was super fast and easy and then I installed the lines and now with everything back together, Im having trouble getting any sort of pressure in my front brakes. My rear works perfect and I changed lines/pads there too.

Watched a ton of videos and checked out the GSXR forums but can't seem to find out what the issue is.

Ive bled them three times now, both calipers and the master cylinder. Only fluid seems to be coming out and YET I have zero pressure whatsoever in the lever. Allbanjo bolts are tight, no leaks as far as I can tell, not sure what to do! Only thing I could think of was leaving the lever depressed overnight which I just put an elastic on an hour or so ago but besides that I'm stumped.

Any help appreciated, thanks guys!
 

J_F

Well-known member
Site Supporter
2 possibilities:

1) master cylinder decided to fail at the same time you did the other work

2) air in the system

number one is very unlikely

moar, and better, bleeding!
 

PrivatePilot

Ironus Butticus
Site Supporter
There's air somewhere.

Try a reverse bleed. It was the ONLY thing that worked last time I had my brake system open to air. Many hours of frustration trying to do it the traditional way (even with a speed bleeder) solved in 30 second using a big syringe and the reverse bleed method. Should have done it way earlier but I'm stubborn like that.
 

Mad Mike

Well-known member
  1. Make sure your bike is standing up straight, lots of bikes are tricky to bleed on sidestands.
  2. use a bleed hose and jar off the bleeder, hang the jar above the caliper.
  3. start on the caliper opposite the master. Move 200ml through that side before moving to the otherside. Repeat.


things to watch for:

  • bubbles in the bleed stream - bleed till you see none
  • never let the master get low
  • If you changed lines, make sure the slope from caliper to master has a constant drain slope— no high points
  • if you have ABS, consult service guide, ther May be extra steps
 

Wyled

Well-known member
Just to address a few more things you guys asked/mentioned

I think air being somewhere seems to be what it is. I'm gonna take a look at it in a bit again and do another bleeding with the remainder fluid I have.Ill probably go to dollarama and get some syringes to do the reverse attempt.

Both Suzuki recalls were completed in 2018 as for the seals I replaced I forgot to mention I did the piston seals, did not touch the MC

Thanks guys, I'll update again if necessary or when I manage to solve it.
 

BigEvilDoer

Well-known member
Just to address a few more things you guys asked/mentioned

I think air being somewhere seems to be what it is. I'm gonna take a look at it in a bit again and do another bleeding with the remainder fluid I have.Ill probably go to dollarama and get some syringes to do the reverse attempt.

Both Suzuki recalls were completed in 2018 as for the seals I replaced I forgot to mention I did the piston seals, did not touch the MC

Thanks guys, I'll update again if necessary or when I manage to solve it.
Good idea on doing it reverse - it's the only way I change the brake fluid anymore.
Once you feel you've got it refilled bottom up, Put a zip tie around the bar and brake lever. Squeeze it tight, pull the zip tie so the lever is as far in to the bar as it goes. Leave it sit overnight. Then bleed again. With luck, any bubbles will be pushed up to the top and pop out easily with the bleed.
 

Wyled

Well-known member
Hey guys. Came down today and took the zip tie off, the brake lever seemed to have atiny bit more pressure but still was bottoming out so no luck there. Gonna try the reverse bleed tomorrow I think. I spent some of today doing a complete flush and reattaching the lines. I did find one of the copper crush washers to be pretty tattered from the installation so i thought maybe that was the cause. Except, there were never any leaks from the banjo bolt/failed washer so I don't think that is the cause.

I ended up getting new crush washers and reinstlaling the lines, doing the flush and then finally bleeding the entire system again except I still had spongy brakes. I put another zip tie around it today and if I go down tomorrow and theyre still spongy I'll use whatever fluid I have left to give the reverse bleed a shot, hopefully that sorts it out. I also noticed that my front wheel does not spin freely. One side of the the pistons from each caliper have closed the pads around my rotor but I'm not sure if that's normal and the only reason the wheel stays stuck is because the piston won't lift the pads off my rotors? ANyone know what I'm talking about? Anyways probably doesn;t really matter since I dont have working brakes anyways.
 

Trials

Well-known member
It's still all just air in your system, do the syringe trick and push your oil in from the bottom :/ air in liquid always rises, it can't do anything else.

imho, the depressing the lever does nothing for you, neither oil or air can pass backwards through the brake master cylinder when the piston is depressed, otherwise you didn't assemble it correctly, or the seals are shot. Your brake pads are dragging because you have compressed air in the system.

Before you do the reverse bleed you need to push all the pistons all the way back into the calliper assembly first. If you miss that step you will never get all the air out.
 

Wyled

Well-known member
It's still all just air in your system, do the syringe trick and push your oil in from the bottom :/ air in liquid always rises, it can't do anything else.

imho, the depressing the lever does nothing for you, neither oil or air can pass backwards through the brake master cylinder when the piston is depressed, otherwise you didn't assemble it correctly, or the seals are shot. Your brake pads are dragging because you have compressed air in the system.

Before you do the reverse bleed you need to push all the pistons all the way back into the calliper assembly first. If you miss that step you will never get all the air out.
Thanks for this, so I'm just forcing my piston back into the calipers, do I need to watch out for anything? Would the front M/C rise because of that? Thansk
 

Trials

Well-known member
Thanks for this, so I'm just forcing my piston back into the calipers, do I need to watch out for anything? Would the front M/C rise because of that? Thansk
Yes it is going to overflow the master cylinder reservoir unless you use a syringe to evacuate the old oil out of the reservoir and then top it up to the correct level. put rags around the bar to catch fluid spills.
 

ToSlow

Well-known member
Site Supporter
Yes it is going to overflow the master cylinder reservoir unless you use a syringe to evacuate the old oil out of the reservoir and then top it up to the correct level. put rags around the bar to catch fluid spills.

brake fluid will mess up paint if you’re not careful
 

Trials

Well-known member
... feels weird on the skin too.
I had the front brake go all the way to the bar today and pretty near plunged a bike into the lake on a steeper then 45 degree slope :LOL: not sure what happened there, I switched bikes and need to service that one before I ride it again or possibly drown.
 

racepro171

Well-known member
try having someone hold the calipers up above the master and bleed that way, had to do that one before
 

Wyled

Well-known member
Still stuck with very little pressure (lever can bottom out). I think i've tried everything on this thread and still can't to get the air out. Am I just out of luck? What would your guys' next step be? Take it to a shop? Is there anyone close by the highpark area with some free time who'd be willing to come bleed and get some pressure into my system... Id pay of course.
 

ToSlow

Well-known member
Site Supporter
run a small hose from the bleeder back to the res and pump the handle a few times. that way it sucks and pumps fluid both ways
 

Trials

Well-known member
(y) like a kidney dialysis machine to bleed your brake, I love it.
 

Wyled

Well-known member
run a small hose from the bleeder back to the res and pump the handle a few times. that way it sucks and pumps fluid both ways
Am I bleeding it like normal (pressurize, crack, close, release) when I do the handle pumps or am I just pumping back and forth with the bleed nipple wide open. Also does the hose need to be sitting inside the fluid of the resevoir, and be full of fluid itself or can the hose connecting the two have air pockets in it since it wouldnt be full of fluid
 

ToSlow

Well-known member
Site Supporter
yes attach the hose to the bleeder when it's open and run the other end of the hose so it's submersed in the res brake fluid and pump the handle
 

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