Bleeding disc brakes??

[XTC OKE]

I have just installed the new XTR disc brakes and started bleeding but I used a syringe from the caliper filled with mineral oil and injected the oil through  to the lever closed it and thought it will work but as soon as I pulled the lever it goes flat to the handlebar and only minimal braking...

 

What to do??

 

[turtlek]

lots of pumping (of the brake caliper) you have to work on getting all the air out of the brake cables and it requires a few refills of mineral oil

[Guest Big H]

Hope has a bleed kit where you force the brake fluid through the system form the reservoir by using pressure form a bicycle wheel. It works, is not messy and is efficient. Maybe change to Hope disks or find out if Shimano has a similar kit??????

[SwissVan]

I have just installed the new XTR disc brakes and started bleeding but I used a syringe from the caliper filled with mineral oil and injected the oil through  to the lever closed it and thought it will work but as soon as I pulled the lever it goes flat to the handlebar and only minimal braking...

What to do??

 

Sounds like your syringe might be to small (i.e. not enough brake fluid being pushed through), try and get the biggest syringe u can or a specific brake bleeding bottle.

Also need to make sure that no air is being sucked in while filling up from the bottom, air can be pretty devious and finds its way everywhere...

 

And.. did u open the resevoir (on the top) to allow the excess fluid and air to escape?

 

That being said i dont even know if bicycle disc reservoirs have a "bleed point" that can be opened for bleeding purposes, i'm talking from other bleeding experiences not bicycles.

 

 

[L'Bie]

I battled though a learning curve myself and found the following working well. Open the resevoir on the handle. You might have to loosen the brake handle and rotate for the resevoior to be level with the floor. You must have a short length of tube fitting tight over the bleeding nipple on the caliper. Fill the syringe and make sure there is no air. Loosen the nipple and inject the fluid into the break system from the bottom. Be patient and do it slowly to allow the bubbles to stay close to the top of your fresh fluid. Don't over fill the resevoir. Pinch close the nipple when the disired level is reached, re-fit the diaphragm in the resevoir and close-up. Re-allign brake handles, cleanup and enjoy.

[TitusTi]

L'Bie, spot on, with the Shimano's a little patience is in order, do it properly the first time (they do come with instructions) and you won't have a problem for a long time.

[Dirtbreath]

I have just rebled XT brakes. You actually have to fill the reservoir right up to the top so when you flip them there is no chance of any air being in there.

[XTC OKE]

 

I battled though a learning curve myself and found the following working well. Open the resevoir on the handle. You might have to loosen the brake handle and rotate for the resevoior to be level with the floor. You must have a short length of tube fitting tight over the bleeding nipple on the caliper. Fill the syringe and make sure there is no air. Loosen the nipple and inject the fluid into the break system from the bottom. Be patient and do it slowly to allow the bubbles to stay close to the top of your fresh fluid. Don't over fill the resevoir. Pinch close the nipple when the disired level is reached' date=' re-fit the diaphragm in the resevoir and close-up. Re-allign brake handles, cleanup and enjoy.[/quote']

 

I have dont that 2 times allready

 

[SwissVan]

I battled though a learning curve myself and found the following working well. Open the resevoir on the handle. You might have to loosen the brake handle and rotate for the resevoior to be level with the floor. You must have a short length of tube fitting tight over the bleeding nipple on the caliper. Fill the syringe and make sure there is no air. Loosen the nipple and inject the fluid into the break system from the bottom. Be patient and do it slowly to allow the bubbles to stay close to the top of your fresh fluid. Don't over fill the resevoir. Pinch close the nipple when the disired level is reached' date=' re-fit the diaphragm in the resevoir and close-up. Re-allign brake handles, cleanup and enjoy.[/quote']

I have dont that 2 times allready

 

 

Well dont try that see if we care

 

Bigger syringe more fluid more fluid pomp it full till all the air is out even if the reservoir overflows and close the nipple while fluid is still flowing.

Wipe up mess

 

 

[Cassie]

I need to bleed my brakes....

 

Where can I get mineral oil from? (Not LBS - shimano stuff...they are way too expensive!!)

 

Thanks

 

[crasher]

Took my bike to coolheat and they swopped around my hoses and bled my brakes (SLX)

I watched them do it they make it look so easy but whilst we were chatting they said how easy SLX was to bleed and what a B*tch XTR could be.

They bled the brakes to start with like a car with a couple gentle lever strokes and finished off with a back bleed with syringe via calipers.

they would bleed a tiny bit with syringe then a gentle squeeze or 2 of lever and you see bubbles rise in reservoir then a bit more with syringe repeat untill no more bubbles and lever is stiff it looked easy but they know what they are doing.

One thing no one here has metioned is that they fit a plastic wedge/ spacer to hold the caliper pistons in position before they bleed did you do this XTX oke? as I assume it would be a similar set up?

 

[Cassie]

Yes, the plastic wedge (it should rather be flat spanner of some sorts - about the rotor's + 2 pads thickness, in order not to make the piston compress skew...) provide a resistence to the hydraulic pistons...

 

Interesting about the back bleed via syringe....I did not know that!!

 

Thanks for the advice.