Solution for brake "pump up" - Ducati.ms

GHEZZI · Feb 9th, 2009, 4:02 pm

Well guys, we may have a solution to this dilemma. I spoke with Arthur Brown at a track day Sunday, I believe he has worked for Ducati superbike teams around the world. His suggestion is as follows;

Remove one caliper and its pads.
Sqeeze the brake lever gently several times so the pistons protrude about 10mm. I found it necessary to hold back several pistons so another would release. Indication of greater stiction.
Thoroughly clean with 'brake clean' and allow to dry.
Apply rubber grease around the base of the pistons. I used a tiny match stick sized paint brush to apply a very thin smear of rubber grease.
Push pistons back in, locate pads and re-instal caliper.

The very last piston I sqeezed back in wasn't as free and smooth as the other seven so I will look at again soon.

Result - FANTASTIC! On a short city test ride there is almost no discernable difference between first and subsequent squeezes of the lever. The real test will be hooking hard down my favourite mountain test track behind other riders who surprise me with a lack of corner speed mid-turn and I need to brake again.

My feeling is I had 5 or 6 pistons out of 8 that were sticking or slow to retract and now I may have just one.

The only conclusive proof we can have is if all you guys who have experienced this malady try the above solution and report back.

Caidly · Feb 9th, 2009, 4:45 pm

Nice job. I hope to try it some day as well.

Monstaman · Feb 9th, 2009, 5:02 pm

Great work GHEZZI, I will have a look at mine too.

Another good point to note when putting the front wheel in is make sure the stanchions are free on the axle before torquing it all up, make sure the wheel is nicely centered and free spinning as any drag and off setting of pistons from their relaxed position won't help.

AZ_Scott · Feb 9th, 2009, 5:13 pm

Interesting procedure. One question: What exactly are you referring to as "rubber grease"?

There's a special silicone grease they use on fork seals. Is this the same stuff?

sconly · Feb 9th, 2009, 5:21 pm

i am also interested in this magical "rubber grease" as a mechanic I can honestly say aside from anti-squeek grease that is applied to bmw (cars) brakes I cant think of anything that isnt going to burn up and make a mess or have every little piece of crap stick to it as you drive.

also tough to believe that there is that much stiction on the pistons on a brand new bike, not impossible just tough to believe.

Monstaman · Feb 9th, 2009, 5:46 pm

Rubber grease is an off the shelf grease, nothing new and been around since Gods dog was a puppy.

Used for slave and master cylinders, disc pots etc.

It is a semi fluid grease, not like the grease gun grease.

Quote:

Originally Posted by sconly

also tough to believe that there is that much stiction on the pistons on a brand new bike, not impossible just tough to believe.

I don't discount anything out of the equation now

infanterene · Feb 9th, 2009, 8:45 pm

Rubber grease is a castor oil based grease. It works great on orings, diaphragms and stuff like that.

GHEZZI · Feb 10th, 2009, 12:01 am

Rubber Grease is like KY gel but only more slippery

My tube is about 15 years old and about is big as ya bird (middle index finger) black white and yellow in color. Sold in Australia by Repco (well, 15 years ago) and actually has the words 'brake replacement parts' still visible.

As I said in my original post here, conclusive evidence will only be available if all who suffer, experiment in this manner. Until then I do not wish to debate, theorize or hypothasize on the outcomes.

I have experimented, if you've got the same drama please seek advice, trial and error, experiment etc. I'm not the Guru, I need help too.

Good luck!