Poor Braking - Servicing Calipers, help needed.

[StevenF]

Hello,

Was out earlier in the week for the first time since the good weather started. I noticed that my bakes were terrible, it felt like they were almost non existent. Checked both fluid reservoirs and they're fine. Took a few pictures of my pads as well:

https://i4.photobucket.com/albums/y118/Wonderboy_001/P1000945.jpg

https://i4.photobucket.com/albums/y118/Wonderboy_001/P1000946.jpg

https://i4.photobucket.com/albums/y118/Wonderboy_001/P1000947.jpg

https://i4.photobucket.com/albums/y118/Wonderboy_001/P1000948.jpg

There's clearly still a little bit left on the pads, would think that would effect the brakes that much to be honest.

Any suggestions?
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My Project - Honda CBR 600 F2/FM

[bacon]

Loads of meat left on those mate, getting low is when you can no longer see the line that goes through the middle (around 1mm or less)

edit: reason your brakes could be feeling shit:

* old fluid, rebleed with fresh

* Corrosion, whip the calipers off and give everything a clean with a toothbrush and some brake cleaner.

Its also possible your pistons have seized a bit, rain and dirt gets behind the dust seals and corrosion effectivily pushes the seals out into the piston making them very stiff. Sometimes even dragging the dust seal out with it



Imo, after winter a full caliper rebuild is defo worth a few hours on a sunday. If you decide to do this you will need:

*small electrical screwdriver for scraping dirt from inside dust seal grooves
*Red rubber grease
*Cotton wool buds are good too for cleaning the seal grooves and inside the caliper once the hard stuff has been scraped out.
*brake cleaner
*toothbrush
*copper grease


Get an allen key and partially undo the caliper half bolts, don't undo them, just loosen the initial bite off them (will be hard when they are off the forks later)

Remove calipers from forks, remove pads and stick some wood between the caliper halves on both calipers. Pump them out until they are all nearly out (wood stopping them popping out completely)

Remove from brake line and drain fluid.

Split calipers in half (if you didn't loosen these earlier you will be having fun now, done it myself several times they can be tricky as you cant hold onto the caliper easily)

Clean the caliper body with brake cleaner and the toothbrush.

With the pistons nearly all the way out, they should be easy enough to pull out by hand with some pursuasion.

Remove all seals and leave to soak in brake fluid. The dust seals are only really what gets knackard with corrosion, but should be able to re-use most of them if not all of them with some luck.

Clean the seal grooves with the fine screwdriver, scraping out the white crap, using brake cleaner over them and cotton buds to remove any other dirt.

Once spotless, pack the seals with red rubber grease and reinsert seals, brake seals first, then dust seals. Wipe off any excess red grease that comes out from the seal. Clean up the pistons with some brake cleaner and a rag, dip in some brake fluid and reinstall them into the caliper. Some people like to put red rubber grease on the exposed piston once they have been put back in. Push them in flush to the caliper.

Join the caliper halves back up (loctite on the joining bolts, torque them up once the caliper is back on the bike), copper grease on back of pads and the pad pin etc and put them back together. Install back on fork. Torque the bolts with a torque wrench

Bolt the back to the banjo and rebleed with spanky clean brakes

Spam reply over

[MarJay]

They look fine to me, but if I were you I'd be more worried about the calipers being seized than anything else. As I recall the CBR600 in your avatar has sliding calipers, and so it could be that the sliders are corroded and the calipers don't want to move.

I'd take the whole lot off, strip and clean it, and free off the pistons if they are stuck. If the brake fluid is old, a fluid change would not go amiss.
____________________
British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[MarJay]

[bacon]

Ah didnt realise they were sliding calipers, they should be quicker to service then with half the pistons and seals

[StevenF]

Thanks guys, that's my next task then. I've only ever changed pads on my car, never serviced brakes before so should be fun!

Thanks Bacon you that guide, it'll steer me in the right direction!
____________________
My Project - Honda CBR 600 F2/FM

[StevenF]

Would it be ok to use WD40 on the callipers rather than brake cleaner?
____________________
My Project - Honda CBR 600 F2/FM

[MarJay]

[StevenF]

[MarJay]

[tatters]

Thats not the pad pin but a brass cap, the pin has a allen type bolt head under the cap.


If the cap wont come off when heated you need to drill it.
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Past:NRG50,AF1125(x2),NSR125RR,ZZR250,CX500,VFR400,KR1S,ZZR600(x2),CB400N,YZF1000(x2),KH125,Z200,FX400R,CBR954RR(x2)GPZ500S,GT550,VFR750F(x2),RD350N,XR650R,CBR600F,CB250,KDX250,YZF750R,CRM250,400EXC,KLR650,TTR600RE,DR350S,R100GSPD,RGV250,VMAX1200,DL650,KZ750 Present:G650XC,C12,CRF450X,1190ADV

[StevenF]

I finally got round to dong this today. I've taken the rear calliper off and split it in two and cleaned it all with brake fluid, but I can't seem to get the pistons to come out in order to clean them. Any idea what this is?
____________________
My Project - Honda CBR 600 F2/FM

[tatters]

Blasted them out with compressed air, wrap them in a rag first as they can pop out quite fast.
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Past:NRG50,AF1125(x2),NSR125RR,ZZR250,CX500,VFR400,KR1S,ZZR600(x2),CB400N,YZF1000(x2),KH125,Z200,FX400R,CBR954RR(x2)GPZ500S,GT550,VFR750F(x2),RD350N,XR650R,CBR600F,CB250,KDX250,YZF750R,CRM250,400EXC,KLR650,TTR600RE,DR350S,R100GSPD,RGV250,VMAX1200,DL650,KZ750 Present:G650XC,C12,CRF450X,1190ADV

[StevenF]

[AndyB1989]

re connect the brake line and pump them out

[StevenF]

Ok so we have some progresses. Front brakes stripped down yesterday, cleaned, reassembled and after many hours I got them to bleed properly!

However the rear calliper pin has rounded off and won't turn. I going to pick up a new one today, but I need to get the old one out! The only way I can think of is drilling it out but unsure how to do this properly!

Any advice please?
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My Project - Honda CBR 600 F2/FM

[Robby]

Is it the pin that has seized, or is it a blanking plug before the pin?

Try an impact driver first, and worked for me. If not, try drilling it, but only to a depth of 4mm or so. Make sure the drill is centred, start with your smallest bit and gradually work up until you can remove the old plug, you may end up pulling the spiral thread of it out of the threads in the caliper body. Good to run a tap through the threads afterwards. If you done have a tap then a bolt of the correct pitch will clean them, use some light oil like 3in1 on the bolt while you wind it in to help pick up any crap.

If you damage the pin, get a new one. They're surprisingly expensive for what you get, about £5 each.

Corroded pins is a very common cause of sliding calipers performing poorly, even a fairly small amount of corrosion as on yours can have a major effect on the brakes.

If you haven't already, clean up the corrosion behind the fluid seals as bacon says. You'll probably be surprised at the amount of corrosion that you scrape out, falls out as white powder.

You'll have incredible brakes afterwards, bear this in mind the first time you use them. I nearly fell off the bike doing a low speed stop, a moderate squeeze felt like hitting a brick wall.

[StevenF]

Thanks for that Robby. It's the actual pin that's stuck. I managed to get the blanking plate out but the head of the pin is rounded so won't turn. I tried hammering a slightly larger trox screw into it but didn't work.

I don't haves tap so will need to buy a bolt the same size from somewhere and try that.

One more question lol. I get the drilling the smallest drill bit into the pin, but how do I actually remove it?
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My Project - Honda CBR 600 F2/FM

[Vincent]

Is the end of the pin visible? You can sometimes drill them from the back and they just start to screw out once the drill bites. Or get an eazy out or similar and drill backwards from the top.

[StevenF]