bleeding brakes

[silk186]

I have a GT avalanche 1.0 with Tektro Auriga comp disc brakes. I'm going to be selling it soon but I was thinking to bleed the brakes. I don't have anything to do it with so I would need to buy a kit to do so. If I do, would it be suitable to do a few set of brakes and work with different sets of disc brakes, or will I need to buy a new kit if my next bike comes with Shimano disc brakes.

What is a good bleeding kit to get, cheap, good for a few uses and compatible with different brands?
Or is it cheaper to buy individual parts from a hardware store?
Kits seem to range in price from £10-50

 

[Cubist]

Essentially a bleed kit is a syringe and a short length of 4 mm plastic hose, plus a bottle of fluid. Some systems need or benefit from a screw in connector on the reservoir, but they are convenient rather than essential. The cheapest kit on eBay is Dans kit, which is about a fiver and comes with instructions for your brakes.

The kit will do any Tektro or Shimano brakes that use mineral oil.

 

[lpretro1]

Why do you want to bleed it - not something you do as a matter of routine as you can cause more problems than you fix if you are not careful - only bleed if brake has air in it. This usually manifests itself by a spongy feel to the lever initially then if you pump the lever a few times it firms up. For any other problem it isn't a bleed that is required.

 

[silk186]

This is my first purchase of a bike with disc brakes. The brakes feel very loose and the front doesn't work very well.
A friend said that I need to bleed the brakes to fix them.

Watching so youtube videos it seems necessary. I don't know the age of the bike.
I disc blocks necessary when bleeding?

 

[Cubist]

Advisable, but a piece of ply the right thickness, or even the rotor will stop the pistons closing up.

The kit I linked to works by flushing upwards from the caliper.
To explain in detail, the system has fluid in a reservoir at the lever. This will be fitted with a cap using two small hex capscrews. Get the bike in a stand . Use a 4mm hex key to loosen the lever bar clamp and rotate the lever so it is horizontal, and higher than the caliper. Clean around the reservoir and lever assembly. Undo the cap screws holding the reservoir cap in place and put them somewhere safe. Ditto the reservoir cap and any seal or diaphragm, noting the order of assembly. .

Wrap a clean rag under the reservoir to catch any spilt fluid. Now drop the wheel and use a flat blade or screwdriver to gently prise the pads as far apart as they will go. A wide plastic tyre lever is ideal. This pushes the pistons home into the caliper. Now remove the pads and put them somewhere where the won't get covered in mineral oil/fluid.

Fill the syringe two thirds full with mineral oil, and attach the plastic hose. Using a cloth, turn the syringe point upwards and tap and squeeze to remove any air bubbles, gently squirting the syringe until the plastic hose is full of fluid and no air. Catch any fluid in the cloth.

Put an 8mm ring spanner over the bleed nipple on the caliper. You may have to remove the rubber cap first. Attach the open end of the plastic hose and turn the ring spanner a half turn or so. Squeeze fluid from the syringe into the caliper, and watch to see contaminated/air-filled fluid welling up out of the reservoir. It'll overflow and run into the rag you wrapped round underneath it. Once the fluid runs clean, close the bleed nipple and remove the syringe. Wipe up any spilled fluid with a cloth and clean with Isopropyl Alcohol.

Now, ensuring the reservoir is full to the brim, replace the diaphragm, and replace the reservoir cap and screws. The system is now chock full of fluid and no air. Again, use IPA and a rag to clean up any spilt fluid.

Clean your hands and replace the pads (with new ones if the pads are less than 1 mm thick, ) Now, either replace the wheel or put a piece of ply or whatever between the pads, and pump the lever to pressurise the system.

Adjust bitepoint or reach to suit and go ride.