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kwiggins29059, Motorcycle Mechanic
Category: Motorcycle
Satisfied Customers: 2915
Experience:  Experience in Harley Davidson and Triumph
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When I pump the rear brake on a 2001 750 fluid pumps out of

Customer Question

When I pump the rear brake on a 2001 750 fluid pumps out of the resivoir and no pressure to the caliper. What's going on? We replaced the master with no change.
Submitted: 1 year ago.
Category: Motorcycle
Expert:  Kenny O. replied 1 year ago.

Hi my name is ***** ***** still have "air" in the lines, some of these Ducati's at least the ones I'm familiar with has to do with the geometry of how the master cylinder to the caliper relation is configured.

One tool to combat this is to have a power bleeder, not sure Dennis if you have access to one or have been using one but if you have a Harbor Freight tool store by you they have a pretty inexpensive one that will work, so having one of those to pull the fluid through rather then pushing works much better.

Next you NEED to make sure that the either the master cylinder or the caliper is higher on plane then the other, what happens air (bubble) can generally get stuck at one of the connection points (banjo bolt) on the brake line, I usually try to get the master cylinder higher over the caliper and then the banjo bolt where it is located in the master higher over the bleed holes inside the master cylinder. I know this doesn't make a lot of sense so I will post up a diagram of what I'm trying to explain.



Expert:  Kenny O. replied 1 year ago.

Dennis, I put together a little diagram of what I explained to you earlier, let me know of it make sense and or you have any questions.



Customer: replied 1 year ago.
We've done that. Hand vac bleeder, caliper turned over so bleed nipple us on the high side and above the master with a tool between the pads
Expert:  Kenny O. replied 1 year ago.

Not sure of the tool you are using between the pads but I would mount the caliper up so the rotor is between the pads, you might be getting movement on the tool verses between the rotor. You have air trapped at one of the banjo bolts I'm sure of that, that is why you are getting no pressure, so its just getting the right plane when bleeding, believe me I have seen many seasoned technicians struggle with this.


Expert:  kwiggins29059 replied 1 year ago.

Hello, what led to replacement of the rear master cylinder? Just wanting to see if there might be a problem elsewhere causing this.