Twin disc conversion - Kawasaki S1 550 four

in this video I'm going to be showing you how I converted the front brake of my Kawasaki s1554 from a single disk to Twin disk I recently finished Kawasaki s1554 had its original S3 single disc brake on the left hand side and I needed to convert it to a twin disc to make it work better but on the other side there's no lug so I can't open the bolt too so what I need to do is get a spare left hand Fork slider fit it on the right hand side with the brake lugs pointing forwards and then reposition the mud guard brackets as seen here on my Kawasaki s1b 415 that I made in 1996. on the right hand side of the wheel is a Chrome plated cover held on with two screws if this is removed it reveals four tapped holes in the hub for holding a second disc so the first thing I had to do was find the left hand Fork slider that I can modify and this one's in Nice condition with no major marks or scratches so that's just perfect for the job before I could start modifying the fork leg I need to take some measurements to ensure that I get the mud guard mounting bracket in the right place in relation to the caliper bracket to do this I can press it on my Surface table and use the slit gauges to measure the gaps I rest the fork leg onto the surface table pressing down hard to ensure that it sits Square onto the mounting points of the mud guard then I can use my box of slip gauges to measure up from the surface table to the caliper mounting brackets foreign s come in various thicknesses it's just trial and error to get the exact thickness that you need eventually I get to the block that while it's right underneath this means it's too thick so now I'll go back a couple of blocks and you can add thin blocks to it until the blocks slide just nicely underneath the fork leg with The Gap measurement established I can now use this sit block to set the exact Gap and I reverse the four leg round so I put it somewhere safer now so it doesn't get lost the next thing I need to do is very carefully drill through the mud guard mounting bracket with a tapping drill until the hole comes out the rear side then thread the hole the tapping drill for an M8 thread is 6.8 millimeters and this is a nice tight fit in the thread so now I can put it back in my Vise and use my electric drill to drill through they're both the holes drilled the next thing I need to do is cut a new M8 thread I start initially by running the tap through the existing M8 thread until it starts cutting into the metal at the back there we go that's just perfect so now I need to cut off the other parts of the lug that I no longer need using my hacksaw I take some very careful Cuts I can't cut all the way because I might scratch the other part of the fork leg so go down as far as I can then move the fork and cut down a bit further on the other side and a bit up from underneath and I can use a hammer and gently tap it so it fractures off the cast aluminum is quite brittle and the blood Falls straight off perfectly so now I can take a quick measurement in my Vernier caliper so I can Mark out the other side and cut it in the same place this lugs a lot harder to reach for the hacksaw blade so I have to take little Cuts we get through in the end with both the lugs removed I can now return the fork leg to my Surface table use that slip pack from earlier on putting it underneath the caliper brackets this time to measure the depth for the new mud guard mounting brackets so I hold it down my thumb secure measure with my Vernier caliper up to the surface of the forklug and it's 30 millimeters so I'll make the lug just slightly longer than 30 millimeters so I can adjust it to size I'll make some new logs on my lathe from a bar of 6082 aluminum this is just perfect for this sort of application and it was lovely over to my lathe I slide the bar into the three jaw Chuck and tighten the Jaws securely then I do some measurements on the existing lugs so I can replicate them the existing lugs are 20 millimeters diameter at the big end and the bar is slightly over about 22 so that's just perfect so I can start Machining the initial diameter to 20 millimeters I'll machine down the diameter long enough to make two new lugs with the power machine to the large diameter I now need to turn the compound slide a few degrees to machine a taper to replicate the original lugs to do this I loosen Two Nuts up underneath the compound slide move it around three or four degrees and do them back up I'll do it just by eye until it looks right with the angle set I tighten the two clamping nuts and use the compound slide handle to cut a taper yeah after several cuts the angle is machined and it looks just right I'm really pleased with that so now we can drill and tap a hole in the center and cut it off to length I first use a center drill to drill the center of the bar this ensures the drill will drill nicely down the center and not wobble off line so you can center drill drilled replace it with a 6.8 millimeter tapping size drill from N8 thread with a hole drilled I can now cut the thread the last thing I need to do is set up my parting off blade and part off the new lug to 30 millimeters long so that's the first lock finished so now you screw a bit of screwed Rod into the fork leg so I can screw the new lug onto this onto the thread to align it in the correct place and I can mark it with a pen prior to cutting foreign I can carefully Mark with a marker pen to the profile of the fork leg so I can cut that with a saw file it down to fit nicely ready for welding because of the tapered shape of the new lug I screw a cap head bolt into the end so I can grip that in the Vise really tight to cut with the saw because it's really hard to grab a tapered shape in the rice it just slides out with a sawing complete I can now use a file to file the shape down to the line so now it's already a trial fit on the fork to see how it looks so I offer it by eye first and it looks just right so now I'm going to put a bolt in the center and screw it in tight clamp it up ready for welding with the new lock wires in place it's now time to file it all up so you can't see it this takes quite a while with various files to get them until smooth down really nice with the profile roughed out with a file I finish off with some abernet cloth to make a nice smooth surface I'm now ready to go outside and use my angle grinder with a flapper wheel to profile the front side of the fork to remove all the weld I'm using quite a fine flapper wheel so it takes some material off really slowly so you have better control you don't need to dig in and take off more than you want a glass across the garden and there's a pigeon watching me I don't think he's very impressed with the noise but I can't be bothering that much he just drops down has a nice drink the profiles take your shape nicely now and it's starting to look really good just to put a nice shampoo around the edges and smooth it all off and I think I'm ready if I do the next polishing stage so back in the garage I'm on the abernet cloth again to take up all the rocks from the flapper wheel and give it a final buff over the whole Fork before I go back to my shed to use my vintage buffing machine to give it a nice Sheen I don't want a gloss shine just a nice Sheen all right what I'm really pleased with that it just glistens in the bright sunshine so that's going to offer it up to the bike and see how it looks initial indications are brilliant that's going to fit just perfect and now you can see you've got the two lugs at the front of the caliper and the inward pointing mud guard brackets I removed the right hand fork leg from the bike and trial fit the new right hand forward leg but sometimes you can get a bit of distortion with the welding process but this one's slid on beautiful a nice sliding fit so I'm really pleased with that so now I can go back in the garage and put in new fork seals and assemble the fork leg the new rubber forks will tap in nicely with a hammer and once it's down flush with the top of the fork like I use an old copper Bush to tap it in all the way this is very slightly smaller in diameter and allows me to tap the seal down nicely against the shoulder once it's right down I can then put in the round retaining washer and wire clip I make sure the wire clip is fully seated in the groove then to fit on the dust cover so now we're ready for assembly and the thought can go back onto the bike but first i'm going to remove the Chrome cover from the wheel and fit the new disc and here you can see the four tapped holes in the right hand side of the wheel all ready to accept the disc so this slides straight on nicely and the four holes line up just perfect so now I can put on the two tab washer sets and the four bolts and do them up tight and then I bend up the tangs of the tab washers with my pliers with the second disc fitted I can now refit the fork leg and fit the front wheel back into the bike and the right hand hose retainer from a Kawasaki zeb1 fits perfect to hold the new pipe so here it is with the new discs fitted nicely I had all the metal caliper components re-zing plated I've got new pistons and new seals and new brake pads so it's now time to assemble the calipers foreign bodies have been ceramic coated which is brilliant because it's both heat proof and brake fluid proof and it's a nice satin Sheen so the first thing I do is put a little drop of grease inside the bearing sliders on the actual main brackets then I just checked the brake pad fits inside the bracket because sometimes they're a bit tight especially after plating but this one fits in just nice and smooth so I'm really pleased with that I've got new seals and new Pistons to fit and these look amazing really shiny and smooth so they're going to work really well I smear about silicon grease onto the main piston seal this helps it slide into the caliper body nicely and it also helps to prevent corrosion in the groove over time it can be a bit fiddly to fit you just have to sort of get it one side here and then make it flop across and slide down it pops into place and run around your fingers make sure it's seated nicely before attempting to install the piston I put a bit of silicon grease on the Piston as well just to make sure it helps it slide in nice so with a bit of even pressure it gently goes back and pops into place I'm really pleased with that so now we can put on the dust seal I bought a pair of new stainless steel bleed nipples because the old ones are in really bad shape but first I'll put a bit of grease on the thread just to make sure I don't seize in place I tighten the bead nipples tight to make sure they seat nicely in the caliper body I offer up the outer brake pad this has an anti-rotation tongue that fits into a groove on the caliper and must be aligned correctly and is secured in place with a central Bolt you must make sure you use the correct Bowl if it's too long it'll bust through the actual brake pad material and cause damage beautiful I can now install the four rubber boots onto the main bracket these just push on nicely and snap into place the main bracket can then be orientated into the caliper body itself is quite a difficult thing to do it sort of has to slide in and around and go past all the rubber bushes but it does go in and it snaps into place eventually and then you can put in the two long bolts with long bolts in place and that's going to be placed on the back and tightened I then check that the main bracket slides nicely backwards and forwards and then insert the last pad this Palace to engage in the bracket and slide through and this rest against the piston and it all slides across nicely and it looks really great so that's ready to go on the bike it's nice now Springs approaching and the flowers are coming out and the Sun's shining is much better than the cold wet days we've had at winter so now I can get the caliper back on the bike the right hand one slips straight on nicely and the two bolts go in and engage I hear a tapping at the window I think Tracy is trying to contact me so I go back up the garden and then Robin's having a wash in the bath as well as I go past he's having a right we'll flap around in the water he loves it in the water and it's Tracy she's got me a nice cup of tea it's just what I wanted thank you lovely it's always nice to have a nice cup of tea while you're working so now I can do up the right hand caliber bolts in my around here that's nice and tight but the caliper itself is still quite loose which is nice sometimes when you do like the main bolts the caliper itself goes really tight and that's no good it's a new Left Hand caliper goes straight into place nicely replacing the old S3 one I had on there originally this is a KX250 one piece caliper I then reconnect the hydraulic pipe after a bit of reshaping the new right hand pipe fits nicely on the caliper and lines up exactly with the bracket where the hose is going to go it's now time to fit the new right hand hose a new double length banjo bolt allows two pipes to be bolted together onto the bottom yoke the last thing to do is put in the brake fluid and bleed the system this can take quite a while to get out all the air but you know when it's all out you get a nice firm lever I always place an Old Tower over the tank first just in case any drips go on the paint because it can mark it very quickly due to the orientation of the calipers and the position of the pipes the system self bleeds over about a five minute period just by pushing the lever in and out watching ear come up and you can gradually feel the pressure getting better and better and better in the in the end you've got a really good feel with all the air out of the system I replace the Rubber seal and screw on the cap and that's it job done well thanks for watching hope you enjoyed the video I've just sent off the front header pipes to get them re-chromed when they return I'll take the breakout and give it a good test with a new front brake I'm sure it'll go really well or maybe I'll post a video anyway see you all soon

Channel: Allen Millyard

Views: 134,285

Keywords: kawasaki, millyard, home made, shed, shed made, old school engineering, engine repair, Hacksaw, hand cutting, MCN, Classic motorcycle Mechanics, The motorbike Show, HCA, Filing, Files, Colchester Lathe, 1970's, Kawasaki, Haveago, millyardracing, hyperride2, Mikuni, Its fast, Four cylinder, henrycoletv, allen millyard, and it fits perfect, just by eye, four cylinder, kawasaki triple, 90 degree

Id: dnthZTjRI1A

Length: 22min 42sec (1362 seconds)

Published: Fri Mar 31 2023