Ducati Monster Forum

Lots of travel in pedal, so am trying to bleed rear caliper. Can't seem to get any flow to caliper. Reservoir is full, cap is off, tubing from bleed screw submerged in cup of brake fluid. Cracking bleed screw with pedal depressed. Got about 3" column of fluid in bleed tube initially, but no more. No air bubbles either. Removed caliper and hung higher than the master cylinder. No improvement. Is there a ball check in the line between caliper and master cylinder? Bike 2001 has only 3000 miles, so must have been sitting for a good part of it's life. What am I missing? I'm getting ooold, but can't remember what I might have forgotten.

Careful bleeding with the cap off, returning fluid could escape from the reservoir and damage paint.  Try pumping three times slowly, then opening the bleed screw with the lever depressed.  Also position the bike so the reservoir is as close as possible to level as possible.  Also check caliper and master for signs of leakage.

No leakage, and already had one spillage. cleaned and waxed all areas. Caliper is now above master cylinder and reservoir, but still no flow towards caliper. Any way to backfill the line?

I also use a big syringe and thin hose/tube to either pull or push fluid. I've found sucking some out via the bleed nipple works to pull it through the system.

I'm not sure exactly where to find a big syringe. Auto parts or hardware I guess. That might be just what I need. I tried pushing on the expansion rubber reservoir seal as the pedal came up, but I needed three hands. My rubber bulb probably doesn't have enough suck, but I'll try that too. Thanks.

You can get a big syringe at a feed store.

Yes

https://www.youtube.com/watch?v=skaKvS_qH_0

https://www.youtube.com/watch?v=lBk00597EyE

https://www.youtube.com/watch?v=jiWnc4fNGCo

(Start from 6:50)
https://www.youtube.com/watch?v=8JRzN896Uyw

I forgot to include these in the last post.

Webbikeworld review on EZE bleeder. (written in 2010)

(https://www.webbikeworld.com/wp-content/uploads/2010/12/fresh-brake-fluid-1.jpg)

https://www.webbikeworld.com/eze-bleeder-motorcycle-brake-bleeder-2/

https://www.aerostich.com/a-to-b-utilities/tools/maintenance-repairs/brake-clutch-bleeders/eze-bleeder.html

For when you seek perfection in brake/clutch bleeding after pushing or pulling the fluid through with a syringe, reverse vac tool, etc..   Stubborn bubbles that adhere to nooks and crannies within the system can be sonically released along the principle of a sonic parts washer. You need a sonic frequency that frees the tiny bubbles and releases them into the fluid stream. I use decommissioned hair clippers with the blades removed and tape it to the lines. A small vibrio massager could work too. I've seen well bled brakes show tiny bubbles in the fluid reservoir  with the use of devices. Other devices have been enlisted for that role that are outside my experience. A member here shared that trick years ago and it finishes the job to perfection.

On some cars the scan tool has the ability to do that using the ABS valving.  I used to tap the rear calipers with a big wrench to get all the air out.  Never thoght of using hair clippers.  Neat!

rosedalesam, do keep in mind you might have a bad master.

The scan tool flutters the ABS valves. Cool.

I love this forum. "Where's the vibrator, dear?" "Oh, I was just seeking perfection. Let me wipe the brake fluid off."  [laugh] I have syringed the heck out of the system, both pushing and pulling, and am starting to get resistance from the pedal. Not there yet. Pushing from the caliper does not get flow through the master to the reservoir. No bubbles or fluid. Going to let it settle overnight, and try again in the morning. The fact of no flow through the master makes me think it may be the problem, but it WAS working enough for me to think it just needed bleeding. Never had a failed master, just leaky ones that needed seals. I am sitting here ready to search for a replacement master. All of you who have sent advice and help, thank you in advance. I will post results.

 We improvise. Some more than others. ;D

 I can string a pretty good batch of curses together. Too bad I don't speak Italian! I failed to get the rear master to draw from the reservoir or get the caliper bled. I could hear a "goosh, goosh" sound when depressing the pedal, and no change of fluid level in the reservoir. Clogged or failed master is my guess. Bah! I decided to put it back as was(removed the caliper to raise it above the rest) and the forward mounting screw fell into the mounting bracket threaded hole. No thread. Looked at the other mounting screw, and the aluminum thread material was wrapped nicely in the screw threads. It felt a little loose removing, but I've found other loose items,  as I get further into owning my Monster.  Went out and mowed the lawn to cool down. Now, after finding a track stand to remove the caliper bracket, I must decide to helicoil, weld and rethread, or buy new or used bracket, along with master cyl. and reservoir(new or rebuilt), some new banjo bolt washers, and since I'm there, new pads. Recommendation for street riding?  :P

Sintered give more bite, but chew the disc more and can trap heat more than organic pads which give more brake dust.

Helicoils are only good to a certain torque range and then you need Timeserts which are stronger. A good used bracket might be cheaper.
Rear calipers need a good scrub of the rear pistons to ensure they push and retract evenly or trouble starts. Do a search here for all the issues and how to fix them, there is considerable experience with the flaws with this rear brake set up. Ive not had an issue with rear m/c's yet but have seen plenty of gummed up, dragging calipers, cooked discs and fried pads.

https://www.oppracing.com/product_display/361430-brembo-oe-mc-ps-11-silver-without-push-rod/

A brand new bracket should cost about $125.  I Helicoiled my old 750, it held up fine.  Timeserts are much better.  I used what I had. 

Bought a new master cylinder, and a used caliper bracket on Ebay. Found only one bracket that did not have sensor mounts built into the casting. It arrived looking good, until I tried to screw the 8mm bolt into one of the holes. It was also cross threaded. Bah! It did allow me to helicoil both holes in prep to installing it. Back together, new master cal., easily bled the lines and caliper. Also serviced the chain and sprocket, and adjusted the chain tension. Burned the stray brake fluid off the pipes and went for a cold ride today. Makes it all worth it. Thanks for the encouragement and advice!