Bike Disc Brake Caliper Disassembly/Assembly (Avid BB7)

I show how to disassemble and re-assemble an Avid BB7 mechanical disc brake caliper. I also show how the mechanism works. I just thought it would be fun to see what was inside, and see how it works. I cleaned and lube the parts. I replaced the three ball bearings, but I really didn’t need to. If they show wear or damage, they should be replaced. The ball bearings were 5/32” balls. I lubed the parts with marine grease. I considered using Sil-Glyde which I have used for disc brakes on cars. But I decided marine grease might be more available to people watching this video than Sil-Glyde.

Service Manual for Avid BB5 & BB7:


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Hey viewers I have this Avid bb7 disc Brake caliper here it’s a bit dirty and What I thought might be kind of fun is To take it completely apart and see What’s all inside of it and how it works I’m also going to clean it a little bit Put it all back together so basically What I’m going to do is show you the Process of doing like a service overhaul On it but really I just really want to Take it apart and see what’s on inside Of it so I just thought it’d be kind of Fun so let’s go ahead and do this I’m going to start off by removing these Pads what I need to do is take these two Dials here and turn them completely Counterclockwise and that will uh move The pads out So on this one I can use a uh I think This was it uh T25 Torx driver to Unscrew this and so this will move the Little uh Pistons out and then use some Uh needle nose pliers here I grab these And slowly work them out It looks like the spring is still in There Push the spring out Foreign [Music] Okay so I got the pads out So next thing I do is remove this little Knob here do you use a little flat tip Screwdriver and carefully just kind of Pry it up a little bit

Like that now there’s this little spring Part on here and I kind of just pull That off like this put that aside Next I need to remove this little nut That’s holding the arm on there so I’m Going to hold the arm and I’m going to Use an 11 millimeter wrench to turn that Nut That Should be able to remove this arm there So the arm a little washer and a nut Came off of there and I’ll put these Aside And now I want to remove this spring and This little dust seal here see if I can Get this out of here Ah there we go So there’s the spring and the dust seal It looks looks like the spring goes Through that little hole there the dust Seal Another little washer here Now this whole Piston’s kind of loose in There yeah progress Next I’m going to take the main body Part here by removing this Allen bolt And this Allen bolt it’s a five Millimeter Allen bolt so get like a Ratchet wrench here and remove this bolt Here There’s one bolt out And the two bolts are different lengths But should be easy to tell because this Part’s deeper here than this part so it

Should be easy to tell which one goes Where Foreign Clip thing here put that aside and There’s a bearing Came out And there’s two more bearings don’t lose These So there’s three bearings And then this part came out here And put that aside for the moment So now I want to remove this Piston from This half of the body I also want to Remove this plastic part here so what I’m going to do is I’m going to turn This counterclockwise using my T25 Torx Driver and this will unscrew this out of This body but also push this little Plastic uh dial off here So it’s going to be a little tight There so I got the little piston out of There and then I can just slide this Little dial off here like this And so I can go ahead and put this aside And put this aside and put this aside So now I want to remove this piston here So I need to do is unscrew this little Bit here I can either use needle nose Pliers or if you have a Schrader valve Tool here like this you can fit this on There and then just go ahead and rotate This clockwise [Laughter] All right

So there’s that so now I have this all Apart and I’ll put these parts aside So I have the caliper completely Disassembled here and a lot of parts but How does it work well let me show you so This is part of the body here and if you Look inside the hole here there are like Three little channels in there and the Bearings will sit in those channels so I’ll drop those bearings in there Foreign Like that Now this part here also has little Channels on the back side now this part Will fit into here like this And so those bearings are now trapped Between the channels of this part and The body so what happens is the arm will Uh clamp onto there so um when this Rotates This part gets pushed out so you can see That it’s pushed out and so you get the Braking action now this part doesn’t Rest directly against the the the back Of the brake pad there’s this part here Because See how this part rotates well you don’t Want that rotating right against the Back of the brake pad so you have this Little part here which sets in here like A little table and so as this rotates Out This doesn’t turn it almost go right Against the brake pad it just kind of

Will push out of your brake pad and you Get the braking action so that’s how the Braking action works Now what about the dials what do the Dials do okay well I’ll show you so this Little part here Threads into this part of the body Like this and so this dial rotates this Around and so as you screw this in This allows you to adjust the brake pad When you’re initially installing it so As you rotate around this will just push The brake pad in or let it go out a Little bit so you can adjust the brake Pad on the one side Then on the other side you have this Little part This threads inside this little part and Then this little nib here sticks out and So that the the little dial will fit Right onto that so as you turn the dial It it rotates this part inside of this Part here Um which will push this part out or let It in a little bit so you can adjust the Brake pad on that side so that’s what Those do So now these parts are really dirty in Here so what I’m going to do is I’m Going to clean them all up uh the Avid Manual actually says use alcohol but Probably what I’m going to use is like Dish soap and warm water and a scrub Brush and scrub them all up get them all

Cleaned up Well I got all the pieces all cleaned up And they definitely look a lot cleaner Than they did before so now I’m ready to Start putting them back together Now I have it says to grease the parts But it doesn’t really say what kind of Grease to use so I’m going to go ahead And use uh Marine grease uh because it’s Uh like water resistant and also works To higher temperatures so I think this Would be a good choice I’m gonna start off by lightly greasing The threads inside this part here just a Light coating Grease And I’m even playing with a Q-tip Like that And then the next thing is this little Part here I’m going to start threading This into here just start screwing it in And screw it in until it’s roughly flush With the other side And then I can take this part here and Snap it into place Like that Next I want to grease the threads around This part here just again a very light Coating Around the threads there And then this part is going to screw Into this part here And I’m going to use the Schrader valve Tool here to go ahead and screw this in So I can just rotate this

Counterclockwise it’ll screw out Kind of like that So next I’m going to take this little Part here and I’ll just put a little bit Of a grease onto the the end of the ball Here Like this And then it’ll go into the end of here And push it in it’ll stamp into place Take a little bit of pressure There And the next I want to grease these Little uh slots these little ramps here For the ball bearings so I’m just going To lightly grease into there And then I also want to put just a Little light coating of Grease around This part here as well so that it will Rotate nice and smoothly in in the the Body there Okay so now I want to get a little bit Of grease down in the slots in here Inside this body here just a little bit So just squirt a little bit into each Little ramp And they can just kind of smear it Around a little bit in there And then carefully place the bearings Into the little ramps And then if you’re wondering what size Of bearings these are they’re five Thirty seconds inch bearings So you always put brand new bearings in There if you want

Okay got a bunch of stuff to do on this Next little step here first I want to Get a little bit of Loctite blue around These threads right here but I want to Be careful not to get any Loctite blue Down into that little hole there so what I’m going to do is I’m going to get some Threadlocker blue here Um put it onto like a Q-tip here And then just carefully Wipe it around this threads a little bit Now the next thing I want to do is I Have the spring and this little dust Seal here let me get this here there’s Like this little hole in the dust seal There Little hole is going to line up with This hole here in the body so I’m just Get this down into place Kind of like this Next thing I want to install is this Little washer with the hex opening in it It’s going to fit right over there and Fall in around this little hex shape Part there and now the spring Next part is the spring the spring has Pins on both sides One side there’s a straight part that Comes out for the pin and the other side Does not have that uh the part with the Straight part here is going to be facing Out And so carefully take the pin on this Side here put it through the hole in the

Seal and down into the hole in the body Like that now the next thing that’s Going to be installed is the arm here so Now the pin and the spring on that side Is going to go into This little hole here there’s like a Little uh thread screw here this little Slot there that’s where the pin is in The spring is going to fit into So just kind of carefully get that lined Up Bring this around here Um that And then what I’m gonna do is I want to get the Arm here lined up so that the hex shape In the arm is lined up with the hex Shape on the stud There So now the next part that’s going to fit On Is this little lock washer here that’s Going to uh be with the curved side Facing down so that’ll go on there like This And then this little uh nut is going to Go on here And start screwing this on and that’s Going to be an 11 millimeter Uh nut and so I have my wrench that I Used to take it off and use this to Tighten it on And be careful not to over tighten it There

So now if you gotta uh together Correctly This should move nice and smoothly here You got the spring action here and you See this part come out there and so If it doesn’t move smoothly take it Apart try again and you know maybe the Bearings got out of place or something Didn’t quite go right but take it apart Try it again so the next part is I’m Going to take this little spring clip Here I’m going to slide this on here and Then what I want to do is I’m going to Take this little nib here I’m going to Rotate this around so that it’s in line With one of these lines there and then I Can take this part slide it on and I Want to get this little slot here lined Up with the nib there And then this should just snap on Like that And so I got that part going So now I’m ready to put the two halves Of the body together what I’m gonna do First is I’m going to take these bowls And put a little bit of a Loctite Blue on the threads there And so now I can take the the main part Of the body here and then there’s this Little spring clip here and so these Little tabs on either side are going to Fit in the opening here so I can just Slide this in here like this And then it’s got the little flat part

On the other side uh here so this will Fit there and so the tab Will fit Kind of like in these little opening Little Flats on either side here so That’s where that little spring thing Goes there and then these holes are Lined up and so what I’m gonna do is I’m Gonna put in Uh the short screw first no actually I’m Gonna put the long screw in first Um foreign So the long screw is opening here so This will slide down into here Get down into this opening here And start screwing that in It’s a five millimeter hex And I’m not going to tighten it quite All the way yet And Then I want to do the screw in this Other side here and I’m gonna have to Move the arm to get the screw in there So kind of pull the arm aside here Get the screw down through there and Then get it started into the hole on the Other side here And then I can tighten that one down And then tighten this one down here So now I want to torque these two bolts Down so I have a torque wrench here it’s A beam style torque wrench and I want to Torque them down to about 8.5 to 10 Newton meters so I have a five

Millimeter hex socket on there and so I’m going to tighten this down There’s about nine And I got to pull this arm out of the Way here to get to this bolt get that in There and then tighten this down to About There’s about nine newton meters and so Now I have the body all assembled there So now I’m ready to install the brake Pads one thing I want to uh point out is There’s a left side and right side so This one’s labeled R that’s the right Side there’s the this one’s label L That’s for the left side and so the left Side will be on the left side of the Bike is going to be facing to the Outside of the bike that direction and The r is going to be the inside of the Bike it’s going this direction so you Want to make sure that you install them Correctly so Um this is the R1 and notice how these Little uh Nubs here are off center and So is the hinge on this little spring so What you’re going to do is line up the Little uh hinge on the spring between These little Nubs here and the frame of The spring here is going to go to the Right along the outside of the actual Brake pad there so it’s going to sit Right in the place like this And so then the other pads just go right On top here again with the the frame of

The spring right alongside the edges of The brake pad so I’m going to go ahead And squeeze this together and again the L is going to go to the outside here so I’m going to slide this into place Slide it in And they should snap down into place Make sure they’re firmly seated in there And then as you activate you actuate the Little arm there Notice how it squeezes that together and So you have your braking action So that Clean lube and reassemble an avid pb7 Disc brake caliper what do you guys Think let me know that down in the Comments hopefully you found this video Useful or interesting if you did please Give my video a thumbs up if you’re not Subscribed my channel click that Subscribe button down there be sure to Click the Bell so you get notified when New videos come out I’m over on Facebook RJ the bike guy go over there like that Page over there I post a lot of stuff Over there it’s a lot of fun anyway Thank you guys very much for watching

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