Help!
I changed my front brake pads obviously had to push pistons back into calipers to do so. Buttoned everything up and went to bleed them but couldn't get much lever pressure. Managed to bleed enough to establish no air in lines but still can't build up pressure so bugger all brakes!
Ride planned for tomorrow so I'd appreciate any and all advice please!
Vlad, theres still air in there.
Try bleeding them from the master cylinder as the air will have travelled up the lines
I've tried bleeding 40 minutes per side can't see any air. Also can't get pressure to pu h too much fluid out either. Sigh
Quote from: Del on Saturday, 21 November 2020, 06:46 PM
Try bleeding them from the master cylinder as the air will have travelled up the lines
No bleed nipple there though mate eh.
Vlad, what lines you have? Master cylinder, bleed at banjo connection. Lots of rags, towells to protect. Squeeze lever in, undo banjo, re tighten. Air is trapped somewhere.
As Grog said but also cable tie the brake lever to the handlebar and leave sitting overnight.
Over the years I have learnt a few things which have helped me to get good brakes without having any bleeding problems.
I clean my brakes every year and what I do is once the callipers are off and the pads removed I pump the brakes to push the pistons out to get to clean part of the piston and give the whole lot a dam good clean. Then I crack the bleed nipple open and push the pistons back in as far as they go before tightening up the nipple (make sure you have an hose and old bits of rag around the calliper to catch the fluid as it shoots out if not). once they are back on the bike with pads I just top up the reservoir and give the callipers a very short bleed to remove any air that got in. I have been doing this for many years and never have to completely change fluid as it's done incrementally over time. This way ensures I don't push dirty contaminated fluid (or air) back up the system and fluid only ever flows down the lines, not up.
Vacuum bleed them or fill the system from the bleed nipples with a syringe.
It's normal for 14 brakes when dry to be an utter twat to bleed the traditional way.
Hooli, Vlads shouldnt have been dry, just changing pads. One reason i like rubber hoses, just clamp them off before calipers.
I wish I had a syringe or vacuum bleeder.
Vlad, obviously I'm no expert but I just bled an entirely dry system which has got to be more difficult than what you're doing. I'm going to make a few suggestions in case it helps.
I suggest starting from scratch and use the gravity bleed method. Remove the pads and undo the banjos and bleed nipples and push all the pistons all the way in until they stop. That will eliminate the air cushion which might be trapped behind your pistons.
Then with the banjos loose or even off the caliper and bleeding nipples also loose start by topping up the master cylinder until fluid starts to leak out of the banjos then install them back onto the calipers but leave the bleed nipples loose still. Keep topping up the master cylinder until fluid starts coming out of them then do them up. It'll only take a few seconds before fluid starts pissing out of the nipples. I know this because I left mine undone by mistake and fluid started pissing out everywhere.
Now you've got full fluid in the lines and the calipers. Then attach your clear hose to the nipples and make sure the other end is submerged in a cup or bottle with fluid in it. I'm not sure why or how this helps but I was advised to do it and it worked for me.
Now it should be a normal process of bleeding out the remaining little air bubbles in the system and your lever should return. Make sure you don't shake up the brake fluid bottle because that will "champagne" the fluid and you'll get a lot of small microscopic bubbles still in the system. Also don't re-use flushed fluid for the same reason. It's already aerated and useless until it calms down which may take days so use fresh still fluid for the bleed.
This has to work because it worked on my totally dry system. I used several videos to get advice plus advice from a local member and mine are now hard and solid.
@VladTepes , as sa14 says that's how I did mine cos my lines are a lower case h configuration where the secondary line loops over the mudguard from right leg to left,it was a pig to bleed. I got perfectly fine brakes after that
I made vacuum brake bleeder from old fridge compressor, jar, aquarium valve, rubber hose and some silicone. One of the best tools I made for bike maintenance! It took me literally 10 mins to bleed front brakes on gsxr600 and it was complete dry as I had to replace damaged brake pad pins.
Well handle tied back to bar overnight. Nothing.
Just tried bleeding again and it's not getting much liquid through though what is coming out has no bubbles. Oh did I mention I did the crack the banjo at the master cylinder thing too?
There's no apparent blow by so seals are presumably OK.
One of the few things I can think of is failure of pump valve thing in master cylinder assembly BUT that has already been rebuilt with a kit etc. One would hope that wouldn't happen twice in the space of a few years though.
My morning ride is screwed but I still have to get to work tomorrow somehow!!
Looks like I'll have to use your method
@SA14 which I had wanted to avoid because didn't want to pull the calipers etc off again....
But I gots ta do what I gots ta do.
WIll have to head down to supercheap to get some Dot4 as my existing one is running put. It's also been there a wee while so despite having been sealed it might have absorbed somer moisture too I guess. Maybe?
Sigh.
(I did buy a vaccuum bleeder - prob take a week or so though to get here - might make future bleeds a tad easier.)
Until the pros and super experienced come back in with suggestions I'm going to hazard a guess that if you're bleeding fluid out of the nipples and banjos it sounds like your pump is working ok. Have you tried starting all over how I suggested? If everything is working correctly the only thing I can think of is a stuck air bubble somewhere. Let the fluid run out of the banjos then the bleed nipples by gravity as the video suggests. It has to work.
In that video he says that if you get an air sack stuck behind a piston it will be a bugger to bleed and that sounds like what you're experiencing. Treat your system as a totally dry system or even drain it all out again and start fresh. You may even have to pull your calipers apart to make sure nothing's stuck in there or something basic's failed but even if you do that you'll still be up and running within an hour or two like I was and remember, I was clueless to start and it worked for me. So unless you have some sort of mechanical failure in the system it will work and you can still go out on your ride today.
OK so there MAY be a weep on one of the inside pistons of the LHS caliper.
So I may give up and take it to a shop as I have neither the time nor inclination to screw up rebuilding it..
I'd have thought a full rebuild seals would last more than 5 years but...
So would I, 5 years isn't a long time in your climate - blighty, yes.
Me also, last ages normally. Still dont think thats your prob, you would still have lever pressure. Also how can seal leak with no pressure on it. When you pump lever, banjo loose, any fluid squirt out? If you crack caliper connection, does fluid leak out? If it does, any more flow squeezing lever? Its either air or piston stuck in Master.
So if you take the calipers off and take the pads out - are the pistons moving? Take off one caliper at a time to check this. It does sound like there is air still in the system, but I suspect your initial issue was with the pistons (or not all of them) moving properly.
Sometime for bleeding I've found you have to have two people as the bleed nipples can vary as to when they choose to let air out or not - sometimes its a small opening of the nipple, sometime - to get the flow of any air bubbles out - you need to open the nipple 1 or more turns.
I trick that might help
If you can pump out the pistons ( yes with no/ little preasure and get them to go out) then losen the bleed nipples and push them in again re tighten the bleed nipple again .
It can help remove air trapped in am awkward place in the system .
Good luck
Quote from: grog on Sunday, 22 November 2020, 05:38 PM
1 When you pump lever, banjo loose, any fluid squirt out?
2 If you crack caliper connection, does fluid leak out?
3 If it does, any more flow squeezing lever?
1. Do you mean at M/C ? Well it comes out, I dunno about squirt.
2. Brake line banjo at caliper? Yep.
3. Not really.
2&3 actually more flow on the RHS caliper, than the left.
I'm suspecting the master cylinder which is bad coz its the likely most expensive option.... :rolleyes:
/whinge mode on
My missus keeps telling me to sell the bike coz its old and everything is breaking... it's not at 2007, and everything isn't.
Much of it is maintenance but she doesn't see that coz her car just goes to the dealer and gets magically serviced. fixed.
/end whinge
Quote from: VladTepes on Sunday, 22 November 2020, 08:44 PM
/whinge mode on
My missus keeps telling me to sell the bike coz its old and everything is breaking... it's not at 2007, and everything isn't.
Much of it is maintenance but she doesn't see that coz her car just goes to the dealer and gets magically serviced. fixed.
/end whinge
Just as well we don't apply that logic to how much time they spend on their faces. No offence lol, I'm sure she's lovely. Couldn't resist.
@VladTepes 1/ at the calipers at the bleed nipples and the banjo bolts .
I use the same trick in the clutch slave cylinder .
vlad i answered your question on facebook with the pics of vacumn pumps i dont know if you have braided or rubber hoses fitted you can get hose clamps or vacumn plugs that fit into the bango fitting and i would suck out as from the m/c leaving some on the bottom so not let air in
filling than after flushing it into a container clamp or plug than you know there is no air in the m/c try any auto store for clamps or vacumn plugs these are the vacumn plugs https://www.ebay.com.au/i/184325131107?chn=ps
Yeah mate cheers I saw that - have a pump on order.
Will try to see if I can get any pressure at the lever by bleeding at the MC banjo - I only tried it a couple of times , this time I'll persist for a lot longer and see if I get anything.
On account of inability to ride to work, I have had to catch the train with the 'great unwashed'. To be fair though , they are probably worse off as they had to catch the train with me! :lol:
Quote from: VladTepes on Monday, 23 November 2020, 08:10 AM
Will try to see if I can get any pressure at the lever by bleeding at the MC banjo - I only tried it a couple of times , this time I'll persist for a lot longer and see if I get anything.
Well 20 minutes of that was a miserable fail. :angry:
Mate, if master wont pump to top join, as in, push fluid out, its not working. Piston stuck maybe.Seals no good.If piston has been pushed out of its normal travel, seals can be torn by unused part of bore, rough because never used. Reason we only ever do tiny moves bleeding, not total travel.
I just had a look at the pic of your bike in the back in black thread. Do you still have the dual lines off the master?
An idea for you in your struggles, seeing as how bugger all is working for ya.
Take the calipers off the fork, tie them to the garage ceiling by the bleed nipple with a bit of string, getting them higher than the master.
Leave overnight (or a while at least) The idea is the air will go to the highest point, the bleed nipple.
Next day, open bleeder whilst still up there, give a wee pump n close.
Refit calipers & have a try then.
Weird, by may work for ya. The air wants to go up, so let it up n bleed that way or do a reverse bleed in situ.
Quote from: 😎KiwiCol on Monday, 23 November 2020, 06:31 PM
I just had a look at the pic of your bike in the back in black thread. Do you still have the dual lines off the master?
Yes. Nothing has changed there, Usual set up.
Also have a flat ceiling - nothing to tie anything to. It's a bugger.
Got a ladder? Lean it against the bike & use that?
Vlad, a screw in hook? Take it out and park under clothes line?
OK so I tried the above with a shelf and no luck there either.
So I handed it off to RBM Racing at Geebung ( https://www.facebook.com/gaz.rbm/ )
Turns out everything I've done so far is correct - just ineffective because... the pistons are stuck in the bores.
I did give them a very good clean (and they also weren't rusty) before pushing them back, but it took a lot of force to push them back.
In hindsight too much force. (timber plus c clamps)
Several people already alluded to this being a potential problem :onya: as per:
Quote from: grog on Monday, 23 November 2020, 06:30 PM
Piston stuck maybe.Seals no good.
RBM is going to disassemble the calipers whack 'em through the ultrasonic cleaner and see where we go from there.
Hopefully I can get away with a good clean and some new seals, might not cost too much $
So it's a bugger I haven't got the bike back yet but its also good to know at least I was doing the usual / suggested things properly.
Cool, glad you're getting it sorted.
(bloody 4 pots! who'd have them!)
If all else fails Mike get it to a professional :rofl2: :rofl2: :rofl2:
Vlad, i didnt see you mention c clamps and timber. Fingers only or light force. Anyway, a good result coming. 👍
I'm glad the problem was identified (and you're on the path back to great brakes) and wasn't a mysterious thing that no one could solve. I just did my first caliper disassemble, clean and reassemble (not really a "rebuild" because I used all the original seals and o-ring) but can confirm that the pistons should able to be pushed in with medium finger pressure only. If a g-clamp is needed that would have thrown up a red flag for me now that I know but not before. Previously - just like you - I would've considered using some clamping force as normal to push the pistons back in.
Now we know and the good news is that you're going to love your brakes all over again with freely moving pistons if my experience is anything to go by. I wish I was nearby, I would've popped around and we could've pulled them apart, cleaned them up and put them back together again just like I was helped out by an org member. I'd be lost without this forum. Facebook is utterly useless. No accountability. Now, what about your rear brakes? They're next on my list.
Quote from: SA14 on Thursday, 26 November 2020, 08:08 AMNow, what about your rear brakes? They're next on my list.
Rear brakes are an utter doddle compared to the fronts. Even dry they bleed in no time by just pumping the pedal.
Just remember there are two bleed nipples & you need to use both (one at a time or both together, it doesn't matter).
Good tip, thanks.
I use one of these on each piston, I need to get another 2 for the 14, they can`t exert a lot of pressure, but enough and they will hold an already pushed back piston in while pushing back the next one to save going back and forth and eliminating the risk of popping one out too far, used this method successfully for years.
(https://i.imgur.com/RBkgweD.jpg)
Quote from: steve porter on Thursday, 26 November 2020, 01:35 PM
I use one of these on each piston, I need to get another 2 for the 14, they can`t exert a lot of pressure, but enough and they will hold an already pushed back piston in while pushing back the next one to save going back and forth and eliminating the risk of popping one out too far, used this method successfully for years.
Looks the perfect size too. Does it overlap so you can do two at once?
Quote from: SA14 on Thursday, 26 November 2020, 01:59 PM
Quote from: steve porter on Thursday, 26 November 2020, 01:35 PM
I use one of these on each piston, I need to get another 2 for the 14, they can`t exert a lot of pressure, but enough and they will hold an already pushed back piston in while pushing back the next one to save going back and forth and eliminating the risk of popping one out too far, used this method successfully for years.
Looks the perfect size too. Does it overlap so you can do two at once?
4 at once on 4 pots, as I only have 4 I used them on the outside 4 of 6 and held the middle 2 from moving with a sideways tyre lever, I didn't think about it until I did the 14, but I will get another 2 next time I'm at Bunnings
Looks a good idea Steve.
UPDATE
Well I pick the bike up tomorrow – fixed. :boogie:
I noticed as I was doing the previous work above, that there was powder coat flaked off in places.
(I thought powdercoat was immune to brake fluid? :whatever: Maybe not)
It seems that flakes of powdercoat had made their way in past the dust seals, broken down in there and then clogged up the main seal.
It was reportedly "really bad inside there".
Anyway fixed is good, and with the new pads I'm looking forward to some awesome braking again.
While he was at it I got him to bleed/change the fluid for the rear brake and clutch too. Saves me doing it. He also adjusted the chain for me, apparently I'll need a new chain and sprockets sooner than later (but I'm hoping to delay that til next time tyres are needed and just get all that done in one hit).
Would've loved to see pics of how bad they were in there.
me too but I wasn't about to ask him to take pics as he went!
Quote from: SA14 on Friday, 27 November 2020, 03:04 PM
Would've loved to see pics of how bad they were in there.
4 Pots, always messy :stir: :whistling:
Quote from: VladTepes on Friday, 27 November 2020, 02:18 PM
UPDATE
Well I pick the bike up tomorrow – fixed. :boogie:
I noticed as I was doing the previous work above, that there was powder coat flaked off in places.
(I thought powdercoat was immune to brake fluid? :whatever: Maybe not)
It seems that flakes of powdercoat had made their way in past the dust seals, broken down in there and then clogged up the main seal.
It was reportedly "really bad inside there".
Anyway fixed is good, and with the new pads I'm looking forward to some awesome braking again.
While he was at it I got him to bleed/change the fluid for the rear brake and clutch too. Saves me doing it. He also adjusted the chain for me, apparently I'll need a new chain and sprockets sooner than later (but I'm hoping to delay that til next time tyres are needed and just get all that done in one hit).
Vlad give the shop a plug, if it all works out, word of mouth advertising is worth gold. :onya: :onya:
Sorted ! Brakes !@ wooo hoo !!!!! (pics to follow in due course)
Thanks to Gary of RBM Racing at Geebung.
Check out his website: https://rbm-racing.business.site/
and for pics etc see his facebook page: https://www.facebook.com/pg/gaz.rbm/about/?ref=page_internal
Happy for Ya Vlad. Never heard of powdercoat getting into brake seals before.
Sorry forgot pics I'll try to remember tonight.
When you see, you'll believe it.