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Time for my first bleed. DIY or Shop?

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KevinGT

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Discussion starter · #1 ·
My XT brakes have performed flawlessly since I installed them in March 2013. But they are getting a bit soft on the first pull, getting harder as I "pump" them a bit. I assume I just need a bleed.

I've never bled brakes before but I've seen some vids and it looks fairly straightforward. I think I need this:

Shimano Disc Brake Bleed Kit > Accessories > Tools > Bleed Kits | Jenson USA Online Bike Shop

and this:

Shimano Disc Brake Bleed Funnel/Stopper > Accessories > Tools > Bleed Kits | Jenson USA Online Bike Shop

Is that it?

It looks like just a few steps:

1. Remove top bleed screw and attach the funnel.
2. Attach hose and fluid to lower bleed valve.
3. Loosen lower valve and push fluid into upper funnel.
4. Close lower valve and replace fluid with tube and bag
5. Open valve and let fluid/air into bag, adding fluid to funnel if needed.
6. Close valve and cycle brake lever. Open valve, let it drain a bit into the bag, close valve, repeat.
7. Close lower valve and remove tube.
8. Remove funnel and replace bleed screw.

I saw something about actuating the lever after the lower bleed valve is closed but I haven't seen that in all videos so I'm not sure.
 
#2 ·
DIY.

I had the same brake pump problem with my XTR Trails. You can bring it to the shop, but I burped my brakes and saved myself a lot of time (and some $). It takes about 5 minutes. You can find videos of this procedure on Youtube or some other MTB sites.

Parts needed: Funnel and brake fluid.

1) Adjust brake lever so the bleed screw hole is somewhat level. I actually used a bike stand.
2) Remove bleed screw from lever/master cylinder and install funnel (w/o plug).
3) Pour a small amount of brake fluid into the funnel (~5cc). Watch the fluid level and refill so it doesn't go empty!
4) Pump the brake lever gently (i.e., pull and hold for a second or two). Watch small bubbles come up through the funnel. Wiggle the bars a bit to encourage the bubbles to rise in case they're stuck behind something. Flick the caliper, hose, and lever as well.
5) Keep on doing this until the bubbles stop coming up and you get the desired lever stiffness (~3 minutes).
6) Put plug into the funnel and remove. Reinstall bleed screw. Clean-up brake fluid overflow with a rag and alcohol. Restore brake lever position.

KevinGT said:
My XT brakes have performed flawlessly since I installed them in March 2013. But they are getting a bit soft on the first pull, getting harder as I "pump" them a bit. I assume I just need a bleed.
Click to expand...
 
#6 ·
Used to bleed the car brakes with my dad, a 2 man job usually. Process with these hydros is very similar but easier, and with the mineral oil a lot less to worry about corrosion and stuff like that.

DIY for sure, buying all you need to bleed the brakes for 100 times is about 40$ from CRC. Follow Shimano's instructions and enjoy your brakes.
 
#8 ·
I'm in the same boat and the next time there is extended rain forecast I might try it myself. My thought was if I try it myself and screw it up...I have to take it to the shop as opposed to just taking to the shop. So cons I spent a few bucks on mineral oil. Pros I figure out how to do it right and save a bunch of money over the years and am more self sufficient.
 
#9 ·
KevinGT said:
Thanks. First dumb question...do I leave the wheel on so the brakes hit the rotor while actuating them during the bleed?
Click to expand...
I'm going to disagree with some others that say to leave the wheel on. Remove it and the brake pads and use a spacer to limit the caliper puck travel. If your hose comes off the caliper bleed nipple (and it has happened to many) while bleeding, you won't risk contaminating the brake pads with brake fluid. It only takes a few minutes to save an "OH SH!T" moment.
 
#10 ·
You definitely want to the take the wheel and brake pads off and use the thick, yellow bleed spacer that came with your set. Put your pads somewhere safe. I like to take the caliper off along with the brake pads and rest the caliper on a stool so that I can reach the lever.
 
#11 ·
KevinGT said:
My XT brakes have performed flawlessly since I installed them in March 2013. But they are getting a bit soft on the first pull, getting harder as I "pump" them a bit. I assume I just need a bleed.

I've never bled brakes before but I've seen some vids and it looks fairly straightforward. I think I need this:

Shimano Disc Brake Bleed Kit > Accessories > Tools > Bleed Kits | Jenson USA Online Bike Shop

and this:

Shimano Disc Brake Bleed Funnel/Stopper > Accessories > Tools > Bleed Kits | Jenson USA Online Bike Shop

Is that it?

It looks like just a few steps:

1. Remove top bleed screw and attach the funnel.
2. Attach hose and fluid to lower bleed valve.
3. Loosen lower valve and push fluid into upper funnel.
4. Close lower valve and replace fluid with tube and bag
5. Open valve and let fluid/air into bag, adding fluid to funnel if needed.
6. Close valve and cycle brake lever. Open valve, let it drain a bit into the bag, close valve, repeat.
7. Close lower valve and remove tube.
8. Remove funnel and replace bleed screw.

I saw something about actuating the lever after the lower bleed valve is closed but I haven't seen that in all videos so I'm not sure.
Click to expand...
My answer is "Not shop". Sometimes you need a few tries and you are better off alone trying to get it perfect. that being said its not exactly rocket science. The best brakes to bleed imo are formulas and maybe eventually srams since you can attach 2 syringes and just pump up and down to get all air out. the rest of the systems is complete stone age imo in this regard.

Remeber you are getting air out of a system and closing it without getting any air in, thats all there is to it. Personally I prefer dot for performance over mineral and miner over dot if minimal service intervals is sought for.

gud luk
 
#13 ·
DO NOT leave the wheel in your first time. Contaminating pads and greasing up rotors is a major pain to deal with and potentially an added expense.
Definitely DIY as the LBS will charge for one , what you can get in necessary parts for years of bleeding.
 
#14 ·
Cleared2land said:
I'm going to disagree with some others that say to leave the wheel on. Remove it and the brake pads and use a spacer to limit the caliper puck travel. If your hose comes off the caliper bleed nipple (and it has happened to many) while bleeding, you won't risk contaminating the brake pads with brake fluid. It only takes a few minutes to save an "OH SH!T" moment.
Click to expand...
Agree completely with this advice. I used the bleed block last night and glad I did as every time I removed the tube from the port I got fluid on the caliper. Finished up by spraying the caliper down with rubbing alcohol before reinstalling the pads.
 
#16 ·
I think the second poster who described his brake "burping" only worked with bleeding up at the lever end. In this case, i don't see the need to remove the wheel/pads. My understanding of a complete bleed is this: Since the fluid line is at a low point near the BB and swings up toward the lever in front and up toward the caliper in the rear, there are 2 areas where air could accumulate.

If you push fluid in the caliper nipple with a syringe or just open the top bleed screw in the lever, you are clearing air in the front part of the line. If you open the bleed nipple in the caliper and let it drain (either with gravity siphon and/or pumping brake lever while opening/closing bleed nipple) you are clearing air in the back of the line.

Alternatively, if you push enough fluid through at either end you should be able to clear the whole line of air.

I just do the burping procedure up front and a little pit of draining/pumping at the rear.

I don't have any idea if one area is more prone to air than the other. Maybe some of you know.

Good Luck,

Chris
 
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