Bleeding Hope Mini's???
A friend has a set of 02 hope mini's and the lever is getting a little mushy (pulling all the way to the bar without the power from before) i offered to bleed them for him. Now, i have never bled mt bike brakes, however i worked my way through school as a automotive tech so i am hoping i will be ok. my questions are: what kind of fluid do they use, and does anyone have any tips for bleeding them?
all help is appreciated, thanks
The nine most terrifying words in the English language are, 'I'm from the government and I'm here to help.' --Ronald Reagan
- DOT 4 or DOT 5.1 brake fluid -- new bottle
- 2 syringes
- 2 x 20cm length of clear tubing
- 2mm allen key for reservoir cap bolts
- 6mm wrench for bleed valve
- 4mm allen key for handlebar clamp bolts
First, remove wheels and pads. If you happen to contaminate the pads, you can bake them in the oven at 425F for 25 minutes, pad-side up. If you spill DOT fluid on anything, quickly clean it up with some rubbing alcohol. Rubbing alcohol is also great for cleaning dirty rotors.
Rotate the brake levers so that the top of the reservoir in the master cylinder is flat.
Now, instead of using Hope's bleed technique of pumping fluid from the master-cylinder to the caliper by pulling the lever, try filling a syringe with DOT 4 or DOT 5.1 fluid -- make sure there are no air bubbles in the syringe. Using the 6mm wrench, open the caliper's bleed valve slightly.....leave the wrench on the bleed valve. Attach the syringe/tubing to the caliper's bleed valve and gently push the fluid up from the caliper to the master-cylinder. Once the reservoir is full, take a second syringe and begin removing excess fluid from the master cylinder reservoir so it doesn't overflow and make a mess....make sure if you spill DOT fluid that you clean-it all up with some rubbing alcohol. DOT fluid can damage paint, etc., if left too long. Keep pushing the syringe at the caliper and keep sucking out the excess from the reservoir. Once you are nearly finished at the caliper syringe (don't completely drain it), I then use a combination of pumping (Hope's technique of using the lever and bleed valve) and pushing with the syringe at the caliper. You can also use the syringe at the caliper to suck fluid back....this works faster than Hope's technique. You can repeat the pushing/pumping until there is no air bubbles seen in the reservoir and/or syringe.
Lastly, when bleeding, it helps to tap the line and caliper gently with a screwdriver to free any air bubbles that maybe trapped.
When you are done, leave the syringe with fluid attached to the caliper. Then, gently re-install the master-cylinder's rubber bladder and reservoir cap and apply gentle pressure with your thumb on the reservoir cap. Now, gently push fluid from the caliper into the system. Since the reservoir cap is slightly loose, fluid will drip-out. That's OK, just clean-it up. You want to make sure there are no air bubbles trapped under the rubber bladder. Keep the pressure on the syringe and then tighten the bolts to the reservoir cap. Be careful, these bolts are very tiny and can strip. Once tightened and while still maintaining pressure on the syringe, tighten the bleed valve at the caliper. Now, remove the syringe.
You may find that there is now too much fluid in the system, i.e., the pistons/pads are too close. In this case, slowly open the caliper's bleed valve and release a tiny drop of fluid. Close the bleed valve and re-check.
You must choose DOT 4 or DOT 5.1
One thing left out of the last post, great post though! The Hopes are shipped with DOT 5.1. DOT 5.1 is hard to find while DOT 4 is much easier. If you choose to go with DOT 4 you must flush out all of the DOT 5.1 fluid. Good luck! I ended up having to take mine in to me LBS. Well worth the money.
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