View Full Version : Bleedin' Brakes
Sorry to dredge up what should be another simple topic and questions that have been asked a 1000 times before i know and yes i have searched topics but i have exhausted all the options i think.
As you may not know, the bike was left standing for a few years and i am still rebuilding it and have left what i thought would be the easiest job until last. Oh how wrong was I and i have never had problems like it before!
Part of this meant the calipers had to be stripped & cleaned. When i rebuilt them i purchased new OEM pistons and seals (dust and main seal groove was also cleaned out) and they were rebuilt with red grease. Caliper slides & boots were cleaned up and re-greased with silicone grease.
New stainless nipples have been put in and belt and braces, the thread was wrapped in some PTFE.
New stainless lines have been put in - 3 line set up so the original splitter is still in place.
Master cylinder has been rebuilt using a kit and the inside bore is smooth and the tiny return valve hole has been checked to make sure it is clear.
No matter how i bleed, i can't seem to get the lever hard.
I have tried bleeding the traditional way - pull lever, open nipple, let fluid come out, close nipple, release lever - repeat until no more air bubbles come out.
I have tried reverse bleeding from the nipples with a syringe
I have tried reverse bleeding from the nipples with and Gunson Easibleed pressurised from a tyre.
I have cracked all the banjo's to make sure there was no air hiding anywhere here, whilst using the lever method.
I have tied the lever back to the bar overnight with the top loosely on the reservoir
I have taken the calipers off and pushed back and pumped back out the pistons separately in case their was an air pocket behind the pistons.
Tried all the above with the bike on an Abba so it was level and then on the side stand and making sure the MC was at the highest point.
The brakes do seem to apply when i use the lever and release when i let go, it's just the lever is not firm and very easily pulls all the way back to the bar, no matter what i do i just can't seem to get any pressure built up?
Any ideas as to what i may have missed please as i thought i had all bases covered and with all new parts, i wouldn't have thought i would of had these issues and have never been caught out like this with brake bleeding in the past.
Thx
pads take a while to settle into the discs and until then the lever will feel a we bit spongy. bed the pads in for about 100 miles of so then do another quick bleed.
best bleeding is done with a "tube and jar" put brake fluid in jar about 1/4 full then immerse tube end in brake fluid then attach tube to nipple, open nipple and pump the brake lever till the brake fluid fills the tube and watch for bubbles. if no bubbles then on the pull stroke close the nipple then let go of the lever. no need for "open close" of nipple while pumping.
sometimes you need to tap the brake lines repeatedly with a spanner of something while bleeding, this dislodges any clinging air bubbles.
Thanks Bibio - that makes sense. i will give that a whirl next.
yes, sorry I've been through so many things i forgot to mention i have tried tapping the brake lines whilst bleeding as well.
The only thing is that i was hoping to get the bike in for an MOT and the way it is now i am worried about the "excessive travel" fail. The lever adjuster is already on 1 and the lever pulls with no resistance to about 1cm from the grip and then only then can you feel the lever harden slightly.
There is obviously pressure in there as one of the discs you can actually see flexing under the pressure from the pads when the lever is pulled.
as long as it has enough power on the rolling road scale then thats all the tester is looking for.
i have stripped down some shocking braking systems that have passed an mot.
R1ffR4ff
16-06-18, 10:46 AM
This is usually a sign of a sub-par Master Cylinder.You should be able to bleed the front brakes on a Motorcycle in minutes without any fancy gizmos.
I've never had much luck with,"Rebuild" kits so now I just bite-the-bullet and buy a new MC when this happens.
i think your are right R1ffr4ff, I thought there was enough braking power there but took the bike out for a spin and needless to say, there was really no bite there.
While i was out i detoured to the MOT place and the chap there said try another MC as well as i have tried everything else possible - So it looks like i will be ordering another MC. Not due to arrive until the end of the week but will let you know how i get on.
R1ffR4ff
18-06-18, 02:14 PM
Which ones did you buy if you don't mind me asking?
nowt wrong with MC rebuild kits as long as you get the OEM ones. robinsons have them on promotion right now for £9.68 59600-45860. yes that right £9.68 for an OEM kit.
Toooldtodie
18-06-18, 08:50 PM
Jees! Cost me best part of £50 for OEM rear master kit...what gives??
Jees! Cost me best part of £50 for OEM rear master kit...what gives??
its the front one and its on promotion... the promotion might end tonight or tomorrow.. who knows so best get it while you can.
Toooldtodie
19-06-18, 04:57 PM
Still there. Is it the same part for K5 S?
Can't seem to find the answer online...
yes, it fits curvy and pointy naked and sport. its used in a lot of other suzuki bikes as well.
Toooldtodie
19-06-18, 07:53 PM
yes, it fits curvy and pointy naked and sport. its used in a lot of other suzuki bikes as well.
See that's good to know and it is now out in the public domain. You have done us Suzuki owners a favour. Thanks Bibio, again! :smt055
how to x'ref parts:
first go here https://www.ronayers.com/oemparts/#/c/suzuki_motorcycle/parts then pick the year of bike, then pick the model, then look for the part.
once you have found the part then copy the part number and go to Robinsons Foundry https://www.robinsonsfoundry.co.uk/ and from the part number above paste it in to the "search this site" box and then press the magnifying glass. this will then bring up the part, what i like about Robinsons it will also give the promotional price if there is one.
now a little secret about Robinsons Foundry. if your in the UK and the part is full price you can enter TLZO into the code box and it will give you 10% off.
if you want to x'ref parts you can paste the part number here https://www.ronayers.com/ into the Suzuki part number search on the left hand side then press the red search button. it will bring up the part number and at the left it will say "where used" click on that and it will bring up a list of bikes the part is used on, you can then click on one of the links and see where that part is on another bike. this sometimes does not give a full list so you need to manually check other years of the bike you are looking at parts for https://www.ronayers.com/oemparts/#/c/suzuki_motorcycle/parts
Talking Heads
19-06-18, 10:40 PM
In the past I've used https://en.microfiches.net/ to get motorcycle part numbers and info on what other bikes the parts have been used on.
thats a bit harder to navigate. i like Ronayers as it gives all the fiches for a certain bike on one page.
Talking Heads
20-06-18, 10:38 AM
The site I linked to tells you what different market variations of each model are available but your one lumps them all together without any explanation.
Your one is based in the USA, mine is local.
https://www.bike-parts-suz.com/suzuki-motorcycle/650-MOTO/SV/2017
Good that there are choices and its a far cry from the dark days before the internet.
they are all the same parts in the usa, eu etc.etc the only difference is headlights and some ecu's ;)
I bought the MC rebuild kit from Brooks Barn - they have been alright in the past with with seals and other stuff and i got my starter motor rebuild kit from them and not had any issues.
I looked at the price of a new MC - which was about £150. by the time you pay that it is almost worth considering a Brembo unit. So i thought i would take my chance on a decent second hand one which i managed to pick up at a reasonable price but it only arrived yesterday so i have not fitted it yet.
If you are ordering quite a few parts - https://www.motorcyclespareparts.eu/en - are quite reasonable and have come out cheaper than robinsons (but i didn't know about the discount code before).
If you are after K Tech springs or emulators. Reasonable prices from http://firefoxracing.co.uk/ and I have just bought some this morning from them. Was about £160 for both which i thought was good.
punyXpress
22-06-18, 12:53 PM
sometimes you need to tap the brake lines repeatedly with a spanner of something while bleeding, this dislodges any clinging air bubbles.
Years ago after fitting Goodridge front hoses I had the same with my naked curvy.
Tried 'rattling' the brake lever and within half a minute there was enough 'bite' to it to continue bleeding as normal. Whole job jobbed in a couple of minutes. :)
yup lever 'rattling' helps getting stubborn systems started. what you do is flick the end of the lever about 10mm very fast (like a jack hammer), this dislodges the air in the MC.
ok so the mystery deepens......
The good condition MC arrived, i fitted it and bleed the brakes every which way again....lever still not firm. Tried the fast flicking (missus got jealous ;-)) but it didn't help. Had i just regretted buying a "good condition" MC cylinder and should i have just bitten the bullet and spent £150 on a new nissin MC?
Now here is the odd thing, whilst i was here this time it thought i would install the new discs i had lying around. Well, as soon as i installed, a quick bleed again and the lever was a lot firmer now and less travel?! WTF?
It still wasn't right though and as it was getting late i just clamped the lever back to the bar overnight. When i went to have a look in the morning once i released the lever it was still slightly firm (although still slightly better than before) but i now had a pool of brake fluid on the floor from the NS caliper. Took the caliper off and it seems the pressure overnight had forced it way past the new piston seal on one of the pots.
So it look like i may have pinched the seal when i rebuilt the caliper, but not sure why it didn't do this before, i'm assuming because it wasn't building up any pressure in the system.
So fingers crossed, if i remove the faulty piston, check the seals, re-grease and put it back together i am hoping this will resolve the issue.
So it would appear the a mix between new discs and a leaky seal (which didn't show up until the discs went on) was the solution
R1ffR4ff
25-06-18, 08:17 AM
Glad you are getting somewhere.Always the same with older systems that have not been regularly serviced.Starts off as a 10 min job etc.....
Then something else goes once things are disturbed :(
yes very much tested my sanity!
Piston bores were clean and unscored. I deliberately made sure all was good as i was putting in new OEM pistons and seals and given the price of these i didn't want to be pulling these apart so soon or risk marking them when doing so.
still no idea why new discs seemed to have resolved the problem though
Talking Heads
25-06-18, 09:54 AM
Were the bobbins seized on the old discs?
nope they all freely turned by hand
Red Herring
25-06-18, 08:46 PM
Be aware that when you rebuild calipers (and do a really good job) the pistons almost move to easily. This means when you try to bleed the system they move back fractionally when you release the lever (the suction part), giving excessive travel on the lever just as you describe. Once there is enough pressure to push them properly onto the pads and discs they usually say put and the lever firms up. I usually get round this by pumping the lever back and forth really quickly once the system is full and bled, this seems to get the fluid past the master cylinder before the pads have a chance to retract.
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