Motorcycle Front Master Cylinder Rebuild - Part 2 Reassembly

Reassembly of the most common type of front master cylinder kit used on many Honda, Kawasaki, Suzuki and Yamaha Motorcycles.

Transcript

okay so we've got everything disassembled we'll need to inspect the master soldier chassis now looking down in the bore I see a little bit of debris pretty typical there won't need to get it clean this with brake cleaner and perhaps some q-tips and we'll prepare the board in just a few minutes as we look around we have to also reports phew well that I referenced before the larger diameter port is the feed port and it supplies fluid right now the threaded area of the piston here this looks like threads and then the gauge of the seal and pushes a did work this is the relief port this is how fluid cycles back into the reservoir when we release the brake lever is very important this hole is very large and takes a lot of effort to block it this one's quite small it blocks easily if the fluid is corroded so need to make sure that's clear you can use a guitar string and E string you can use the number drill bit you know very tiny pick even perhaps but but be important to ensure that that's clear there's a trick to know that it's functioning properly that I'll be able to demonstrate to you later on in our next video about bleeding process after we need to build calipers looking into the reservoir area here it's not bad fairly clean however there is some noticeable discoloration here where the fluid has begun to go bad remember brake fluid should be replaced to semi annual every other year to ensure longevity and safety and that clearly wasn't the case this one as I started to turn brown we'll need to clean that out again perhaps brake fluid by itself may be a late of a q-tip or Taliban get it in other cases if the corrosion is heavier or more aggressive it could take something as significant as a wire or brush or a soft bristle brush to get all that crews now but need this to be very clean do not want to contaminate our new fluid looking on around here or sunglasses and give shape so it'll be okay probably want to prepare the surface here just a little bit or the ceiling washer works we'll just take some sandpaper and dress that a bit as we go back to assembly so looking pretty good there let's go ahead and do some cleanup prepare the bore cleaner is hard on your hands and stuff's going to spray everywhere I've got some glasses on here so within we're going to shoot down into the toy here I'm good now take a look at her look how pretty that is look at all the debris coming out and this was a relatively clean master solder in the grand scheme of things compared to many I see so if you have a bike you're restoring or bought used components of it sit around just imagine how rough they're gonna be in that case okay so we see the brake fluid here clean your brake cleaner and give this removing most of that corrosion that's a good sign and supplement that a little bit with a little towel action here q-tips can work well again that handy to have a small tipped blunted not very sharp screwdriver so I can get in here and clean off things about great concern of scratching thanks if I were to scratch the bore in here that would be a very bad thing a light scratch that can hold out a heavy scratch couldn't ruin the silver bore and that would be tragic that we'd have to replace the master cylinder we were in the process of rebuilding so if this pretty cleaned out in here and again if here's this owner it could take some effort to get that clean it might spend a few minutes I often times spent more time on cleanup with an older master solder for an overbite then the actual rebuild process takes so you'd even allow for that wipe things down here but overall this pretty clean it's nice to have a component that's not to turbine ready for a change okay good now one of the most important aspects of a master so to rebuild and something that is the most Awkward look by the do-it-yourselfer and even some of the professional folks is to prepare the bore so we have to have those seals sealing well inside this bore and just as you at home a engine cylinder when you're putting new rings in it will need to prepare for surface here break the glaze and put a little bit of a surface finish a couple ways to go after that if you don't do this on a regular basis you can get by with using some sandpaper so I'd like to get some screen twenty grit up here at and give me a little bit of trick together a little tightening it up to you down here about to a couple of tennis I think this is gonna get it we'll find out and I'm going to dip this in some brake fluid get it wet some fluid I'm going to insert it into the bore and then in a twisting manner and I'm going into the wrap so that it tightens the sandpaper outwards against the bar and it's just kind of looking a bit now this is less than optimum but far better than nothing so if you're a do-it-yourselfer and this is the best you can do this is better than nothing because if you just simply put the new seal kit in are not prepared for you may find that it doesn't weight out well it doesn't bleed out at all where it bleeds out the delivers less than optimum level approach now you already see what a difference that's made just with the sandpaper okay so a great improvement there we certainly get you by if you do this on a regular basis you're professional that it more likely to be using a break okay this is just like the homes we use to prepare gives you the cylinders this is just sized for your master cylinders they come in a variety different sizes I don't want to drill your again I'll break through it on it and just as with honing an engine cylinder we want low rpm and a relatively quick inward boom Edward out with movement cuz we're looking to achieve a 45 to 60 degrees crosshatch just as we would with an engine sore often be easier to do this advice don't need to do a whole lot here and the older and rougher condition the bore is in the more hugging will be required this skis not much already prepped with some of the sandpaper you see it's a pretty good sheet compared to the bedding that I see notice some spring back through all the works here I want to make sure I believe all the dirt gum there last thing you want there's a whole bunch of debris and junk in there with our brand new seal set well it's gonna take just a couple of minutes and do some other preparation here that will make your life easier as you go for things I like to do when you paint out flat side down on a nice flat surface draw a few times to clean this surface now this master cylinder is in fairly nice shape but many of them you will find quite a bit of corrosion here and sometimes even some light pitting into the metal and we want to make sure we've got a nice flat clean surface for our diaphragm seal work against and that same token I'm going to do just a little bit of that here when Vanderbilt as well don't forget to aggressive with it don't want to change the shape of it or round it off and just want to ensure it's clean I have seen these leak even with new ceiling washers because there was just enough corrosion there to be a problem and one last spray here to make sure we get her to breathe out and over the towel hang on there these go away a little bit of compressed air is handy to blow this off we have an air can over there we do pressure is great but this is a great handy weight by the air duster things that the office supply store or big-box store and so forth and this is a nice way to [Music] so let's have a look inside this board now and see how much nicer that looks and I think you're gonna be impressed do you see that we have there so again we want that to be prepared very similar to it in the cylinder break the glaze and put a little bit of texture to the surface 45 to 60 feet across and powder so master summer is cleaned up and ready for assembly I will spend a couple of moments here while I'm at it yeah go ahead and clean off my letter pen lucky yeah that's nice pretty good shape some of these will actually require a little bit a cm paper or maybe a brush or a buffing wheel to remove corrosion that one wasn't bad looks real nice inside of the lever just one principal towel through there's the case and a little bit of stuff there not surprising this isn't as clean as that looked and how much junk we got out of that it's the little things like the overlooked and it makes the difference in the long run so we're going to assume that we've already tested our brake lights which is described here and we're going to be satisfied it's good for the sake of this exercise okay so we will be discarding all of these parts because they will come in our new kit which I'll show you in a moment it was in my way so you're break crafters master cylinder kids very complete red rubber grease which will show you how that works in a moment return spring dust cap secondary seal circlip and our piston set now this gets nice and that the primary seal is pre-installed on the piston force this varies it just depends on the kit unfortunately this is not always the case and in some instances we will have to install the primary seal onto the piston and this can be challenging okay now a couple things notice the primary seal is cupped and the cupped open end needs to face inward as that is how the fluid is pushed so I make sure I put it on the piston in the right direction well have taken it off and switch it that's no fun a bit of the red rubber grease here and I don't have to get too aggressive with it and that's kind of challenge of gloves but he gets someone there right where a seal on the piston you want to be gentle blowing across the groove here that the dust boot sits into and now comes the hard part we've got to get it over the flange here into the area where it lives you can see where it's going to end up sometimes again if we're fortunate we'll be able to do this on our fingers and just shove it over there and this is the counter productivity of using the grease which helps us in one respect and makes it more challenging than the other all right now with the gloves on this isn't getting it so let's see if love off I can get lucky enough to push this on here with our fingers or not and in this case not so again my doll blunted small pocket screwdriver a little bit of grease on it very very gently because if I damage the seal then that was the point of the whole process get underneath of it I think you become a squeeze here so I leave meet the pressure okay and then it's kind of a gentle peel a motion I've got to get it over the lip and get it over that lip is the whole challenge once he gets a pass here it gets easy after that I want to stretch it too hard there she goes and even the circlip out and getting a primer a seal on the piston can be your two biggest challenges here I've got gone there I want to be real careful with it but I want to make sure it's not rolled or folded looks pretty good I can see the cup on the inside it's facing the right direction there it's rotating on the piston looking good okay so there we have it now in a similar manner I will be working with my secondary seal it's got a lip right here and that's going to fit into the whole oppressive on I intentionally did not use any grease there because I wanted to stay on here that's gonna eat my assembly not all of these will have that will live but many do store prepared were clean or dry or prepped and so spring to us first and notice as well it's a cup-shaped seal open end is going inwards a bit of the red rubber grease is nice on the edge of this to help ease that installation it's also nice because if you're not in a position to be will immediately move on to the priming and bleeding process got some we brocation here so our seal doesn't dry out another advantage okay so again we go if I'm lucky I can just push it in to rest away with my finger and I was able to do that case sometimes real bit more challenging the flat into my screwdriver here can also be a way to push that in as needed okay so okay so this is our new unit that we received already have the seal on it you get a little bit of rubber grease on here don't need to get crazy with it but I need to get enough on there to provide it lubrication now I'm gonna lay this in here for the moment and prepare the circlet now the stripclub could be almost as challenging to put in and as it was to get out I have spent more time as fighting circlips piston seals and cleaning then the actual rebuild process takes so I'll get it positioned in here I generally try to shoot to have the open end over here near to the lever area opening or it's leisure to access over the piston I'm ready to go you do my finger try to hold a ring on one spot gotta push it down and of course it pops out of it the circlip pliers off to start again the taper on these pliers is causing the clip to jump out there we go good okay so got it down in there finally now it's always a good idea to verify it snapped all the way into the groove it can appear to be it not so again using my little screwdriver here I'm pushing over here little snap there so it was close but not quite so right on the edge the last thing we need is for this piston to pop out of here whether the system is full of fluid remember brake fluid is corrosive to your painted and plastic parts and that's not a good thing so we're in there now we got to put our dust cap on it has to fit into the groove right here so in there sometimes you can get a start with your finger just go around it and it'll drop in there other times it may be easier to just give it a little help with the pocket few traveler and look at that then right in looking good finish it up make sure it is squared and then once I've got it pushed into the groove there need to push the bottom of it down into the unit to get my weather seal be gentle with this again thing I'll blunted screwdriver I don't I poke a hole in my new food that would be very very frustrating all right working the unit smoothly snaps back I'll get there so that part is done we'll take our lever now in this particular case I'm using the red rubber grease because that's what I have here but you would want to use a bobby type grease a little bit heavier duty than this greater long-term use move it there a little bit here now this could be a little bit challenging because we've got to fight against this return spring the master said a little bit to get that started line up on just right there we go that it started and then what's better on in then have to be super tight their briefs want a wipe away and stuck it down don't need to kill this okay but have to be stupid type folks and again making sure make Moo's good there now I'm going to clean up here now of course we can immediately install this on the motorcycle would not need to put it back into the master cylinder because we would be installing it immediately in this case it's gonna be a little bit before we get to the bleeding exercise so get this cleaned up I'm just wiping the initial moisture and stuff off here but I won't want to hit it lightly with a little bit of brake cleaner make sure I leave any residue and the brake cleaner won't get her in the water too if there's any residual water there I'd mess make sure it's nice and dry now the brake cleaner will evaporate on its own but I'd like to get in here in the accordions into the the grooves in the boot if you've got an older unit you're gonna be alarmed or what you see when you do that there's gonna be all kinds of gunk jump it out action and that's yet another reason to replace this piece when you're doing a master cylinder rebuilt you don't want to remove all that moisture one of the best things you can do is try to maintain this clean work area as you can and clean the components as best as possible okay so sometimes there's a little alignment marks of this case there's not just fit it on and I see that it's nice there okay and then check it and assure the fit is good nice and snug again writing letters it marks face the direction of the writer so this company screws on finger tight because we're gonna be going back into this to put fluid in it here in the next couple of days as we give you our demonstration on bleeding so I'll close that up this is enough to make sure nothing crawls in air while I'm waiting to reinstall and make sure reusing our fresh sealing washers on the bamboo bolt okay there's kind of a sharp edge kind of a rounded edge on these I want the sharp edge facing towards the brake line because the sharp edge decided this one is sealed the best and I'm gonna put this in place too so I don't lose track of it so tomorrow when I go to install this weight it I actually know where the bolt is so last thing brake light switch couple things to note a little alignment nub there the lines up with this okay and you know go to be careful the switch here because I've already put the lever on okay so I want to break the nut off so we're gonna push it in so clicked in okay I felt a drop in the notch it's looking good keep it just a little bit of pressure on with my finger in goes the screw again this is another screw that doesn't need to be ridiculously tight I have seen folks actually break these switches by putting a monster torque on the screwed here just snug it down good folks all right yeah there you have it decent master cylinder serviced with brick crafter top quality components everything is looking good everything loose real smooth some shine this up a little bit after I put it on and as matter of fact that's one of the nice things about brake fluid is it will actually help restore this people but don't let it get on the rest of the motorcycles pain so there you have it master cylinder rebuilt ready to install if you've enjoyed this video appreciate if you give us a light you can subscribe to our videos for a full line of brake maintenance and as you climb on your motorcycle to stop and think for a moment what's stopping you thanks for choosing brake rafters and we'll see you next time