Possible leak when bleeding brakes....but where!?

Mrtennis

I bled my avid juicy ultimates today and everything was OK until I got up to the lever. As I started pulling on the syringe to pull any our out of the lever and the system, whilst pulling the brake lever a few times as directed to in the instructions, air seemed to just flood through. The brakes were really bad to begin with but I so much air was coming out that I had to take off the syringe and push out the air, then do it all over again. I did this quite a few times as I wasn't sure whether pulling the brake lever was letting out some trapped air or if it was actually leaking air into the system somewhere.
This was happening on both levers. To finish both of them off I pushed in on the syringe to make sure there was positive pressure on the system. Then closed the syringe. The back brake though just didn't work. I went outside to try the bike out. Both brakes were working, however not well at all. As I kept trying them out pressure was being lost in the rear brake to the point where it doesn't do anything now and the lever just pulls back to the bar. The front brake hasn't got that bad but it doesn't lock on as well as it should and if I kept riding it I am guessing it will also get worse.
So my question is, where is the leak? In the lever or in the caliper? There doesn't seem to be any fluid coming out anywhere which is very confusing! When the back brake stopped working completely I took the wheel off and took the pads out. I then started to pull the brake lever repeatedly to see what was happening. One of the pistons seemed to pretty much come. I think it would have if I hadn't stopped and pushed it back in! There did seem to be some fluid coming out then when it got that bad.
So do I need to buy replacement pistons and seels or replacement reservoir/bladder and seels for the lever? I think they are about £10 for each which isn't bad. But if I replace the lever and caliper parts on both brakes all of a sudden I'm looking at over £40 which I don't want. So how do I work out where the problem is?
Lastly, which bits do I actually need? Some are described as for all juicy systems and some are specifically for the ultimate. Not surprisingly the ultimate are more expensive;
http://www.ukbikestore.co.uk/product/13 ... 1-pc-.html
http://www.ukbikestore.co.uk/product/13 ... 08-09.html
http://www.ukbikestore.co.uk/product/13 ... rnals.html
Will just these seels be ok if it's the caliper that is the problem or will I need the pistons too?;
http://www.ukbikestore.co.uk/product/13 ... -1-pc.html
http://www.ukbikestore.co.uk/product/13 ... t-kit.html

cooldad

What were they like before you started bleeding them? As bad?

Mrtennis

cooldad wrote:

What were they like before you started bleeding them? As bad?

Yup. I bought them second hand. I've bought everything on my bike second hand and everything has gone well...until now

roverthehill

when you have the pads out are all the pistons moving okay and no leaking?

what about the bleed ports - any leaks there? Sometimes there's an o ring at the caliper?

Chunkers1980

Should have bought some m596s

cooldad

Oops. From previous thread.

supersonic wrote:

Why not just use the BB7 and see how they are?! The Avids are an ars* to bleed, squeal, the pistons stick, the lever travel alters on its own accord. Old, outdated and maybe worth what you paid.

Mrtennis

roverthehill wrote:

when you have the pads out are all the pistons moving okay and no leaking?

what about the bleed ports - any leaks there? Sometimes there's an o ring at the caliper?

As I said. Once the brake stopped working completely I took the wheel and the pads out to start investigating. I started pressing the brake lever repeatedly and one of the pistons appeared to be coming out completely. It was coming out but not going back in again. And it kept coming out further every time I pressed the lever.
It was during the bleed of the lever though that everything started to go wrong and where the air started to pour in and the pressure in the lever was lost.
There are no leaks at the bleed ports.

nicklouse

are you sure it was not just leaking in the connection of the syringe?

did the lever creep?

Mrtennis

cooldad wrote:

Oops. From previous thread.

supersonic wrote:

Why not just use the BB7 and see how they are?! The Avids are an ars* to bleed, squeal, the pistons stick, the lever travel alters on its own accord. Old, outdated and maybe worth what you paid.

I wouldn't say it's any of the above that you have listed. The bleeding process was very straight forward. It's the fact that there seems to be a leak in the system somewhere that is the problem. That would cause problems in any system.

Mrtennis

nicklouse wrote:

are you sure it was not just leaking in the connection of the syringe?

did the lever creep?

No, no leak in the connection to syringe. What do you mean did the lever creep?
After reading around a bit I saw someone suggested just bleeding from the lever which takes two minutes. I've actually just given it a go, without pulling the brake lever this time. A lot of air kept coming through and it was filling the syringe again, and it made no difference to the brake. The lever was still hitting the bars and not making the caliper close at all. The fluid that I was able to pull out through the syringe was also very dark and was turning black. Don't know what that is.
Also, thank you for actually seeming interested and trying to maybe help unlike a couple of other idiots.
I am sure I can get the brakes working. It's just a matter of working out whether it's the seels in the lever or caliper which need replacing rather than spending money on both.

nicklouse

creep pull lever. what happens?

Mrtennis

nicklouse wrote:

creep pull lever. what happens?

What do you mean creep pull lever? When I pull the lever nothing happens. It hits the bars withouth any resistance and nothing happens at the caliper end. It was working a bit once I finished the initial bleed but nothing is happening now

maringirl

Possibly lever seals have gone - hence black stuff in fluid? Would need lever strip/rebuild kit.

Mrtennis

maringirl wrote:

Possibly lever seals have gone - hence black stuff in fluid? Would need lever strip/rebuild kit.

Why, what do you think the black stuff actually is? Couldn't it be coming from anywhere in the system?
I should also point out that the second time, this evening, that I went back out to see if bleeding the lever on it's own would help, when I opened the bleed port fluid came out anyway so it certainly didn't seem like the system was empty. Just don't get how the system can seem to be full but there be no pressure there when the lever is pressed.

nicklouse

well re fill the syringe and bleed it without removing the syringe as there is no need to as they will take the air.

if you can not get any feel or if you can not get them to pump up and hold pressure then yes seal will have gone.

air coming into the syringe can just be you pulling it past the seals and is not an issue.

and to your new post you have not bled the brakes yet.

you have tried but not done so.

Mrtennis

nicklouse wrote:

well re fill the syringe and bleed it without removing the syringe as there is no need to as they will take the air.

if you can not get any feel or if you can not get them to pump up and hold pressure then yes seal will have gone.

air coming into the syringe can just be you pulling it past the seals and is not an issue.

and to your new post you have not bled the brakes yet.

you have tried but not done so.

I see what you are saying and I have pretty much done this I think. I put positive pressure (pressed on the syringe) and that gave the lever pressure. That's what I have done on the front anyway. It's not happening on the rear though, which is why I think somewhere a seal must have gone, as you said. The question is where as there doesn't seem to be any leak anywhere.
As far as the front goes. The bleed seemed to have gone well, the lever doesnt pull back to the handlebars but it certainly comes back much further than I was expecting - there's are the first discs I've had. I actually liked the feel of my v-brakes before! So I'm not sure the front one is perfect yet either.
As you say I may be pulling air past the seels which shouldn't be an issue. I did wonder if that's what was happening although I wasn't pulling hard at all. Maybe I have actually damaged them? As soon as I pressed the lever whilst performing the bleed air just flooded through, I didn't have to pull hard. The same started to happen with the front but for whatever reason that has kept some pressure once I finished unlike the rear

97th choice

I treat my elixrs as disposable, as soon as they need bleeding they'll be replaced with shimano. Life is just too short.

Mrtennis

Are these all the bits I will need? I may just need one or the other but I'm not sure. I shouldn't need anything else should I?

http://www.bikegoo.co.uk/product.php/73 ... icy_08_09_
http://www.bikegoo.co.uk/product.php/69 ... it__juicy_

The other question is whether I need to get the same kit for the front brake too.

Come on guys, help needed here! How do I work out where this leak is coming from??? Don't want to buy both kits above if I can get away with just buying one. Just don't know where the leak is!

nicklouse

TBH I say you still need to bleed the rear as you still have air in it.

why did you start to bleed them in the first place?

Mrtennis

nicklouse wrote:

TBH I say you still need to bleed the rear as you still have air in it.

why did you start to bleed them in the first place?

Because this is how it was in the first place. The lever was coming back to the handlebars and it was having no effect on the lever at all. The only air that seem to be in it is coming into the system somewhere as I pull on the syringe. I have pulled atleast 5 syringes worth of air out through the lever. And it's when I pull on the lever that the air just gushes through, like it's opening a hole somewhere. I think this is maybe why when I finished the initial bleed there was some slight braking force but then the more I tested the lever on the road the worse it got, to the point where no it doesn't brake at all, back to where I started at the beginning.
What do you suggest the black stuff is that's coming out into the fluid as I pull on the syringe.
As I said earlier I bought the brakes second hand and I'm just setting them up. I bought them through paypal only so I might be screwed as far as getting some sort of refund goes. Everything else on the bike is second hand and has worked out fine. This is the first bit that I'm having problems with having bought second hand.

cooldad

The black stuff is just dirty fluid. Suck enough through so it starts coming out clean.
There might possibly be a reason they were for sale.

Mrtennis

cooldad wrote:

The black stuff is just dirty fluid. Suck enough through so it starts coming out clean.
There might possibly be a reason they were for sale.

Well they were decribed as fully working.
I'm thinking maybe I need to get a load of DOT5.1 and just try flushing them through as you say. It's just spending more and more money.
To be honest if I can get them working, which I think I can, it's just a matter of spending the money. They're a good brake so probably worth me getting them up and running again. Just wanted to spend as little as possible as that's what I've done with the rest of the bike, got great parts but not spent much on it. Maybe I'll have to bight the bullet in this case.

Mrtennis

cooldad wrote:

The black stuff is just dirty fluid. Suck enough through so it starts coming out clean.
There might possibly be a reason they were for sale.

I'm guessin any DOT 5.1 ok to use? The ones that seem to be marketed for cars etc seem much cheaper than the bike marketed ones

cooldad

yep, all the same.

mrmonkfinger

You don't need that much fluid to flush the old crud out. Maybe 50ml or so. Any DOT 5.1 will do.

You shouldn't get air being pulled in when you bleed the lever. It sounds like a seal in the lever has gone (unless your bleed kit is a bit guff and you're getting air being drawn in through the syringe connection).

Mrtennis

Well I've just been on the phone to my LBS. I actually called to ask if they had the lever service kit in stock that I needed but the guy gave me a couple of tips to fine tune the bleeding process first so I'll give those a try and see if there's any difference. He said when bleeding from the caliper end up through the hose to make sure it is the fluid pushing the brake lever to the open position after it has been held closed during the caliper bleed. More importantly he also said when bleeding the lever just to flick the lever rather than take big pulls on it back to the bar like I had been doing. Give those a try and if they don't work seems like it might be time for new seals

Mrtennis

OK so latest update.
Just been out to give them another go at bleeding. I've managed to get quite a bit of pressure into both levers now but they're still not good brakes, my v-brakes were much more powerful. So I'm guessing they're still not working right.
I started from the bottom up (caliper, hose then leaver) and as soon I got up to the lever again the air was just pouring through. Even just lightly tapping the lever made air come staight through. I kept taking syringe fulls of air out over an over. I know there is a leak in there because air would come out but the fluid in the syringe wasn't going down. So the air must be being pulled through from somewhere.
Regardless, I've still somehow managed to get some pressure in both. I think I am going to get the lever servicing kit though and replace the seals there.
Although, when I started the bleed at the caliper end, I read that I should remove the pads and make sure the pistons are pushed back in. Whilst pushing one of the rear pistons in I could notice one or two tiny bubbles. Is that normal or should it be completely sealed and nothing be able to escape?
So I was all ready to go and get the lever kit but now I'm not sure again. Maybe I do need both!
I also went out on the rode to give the brakes a quick go and the front caliper was permanently rubbing on the rotor and every time a pressed the back brake there was some serious squeeling going on. Was worried the neighbour would be looking out of their windows to see what was going on it was so loud! Don't think it's really worth trying to fix this problems at the moment though while the brake clearly isn't working properly in terms of power as it should. Unless anyone has another suggestion?

bernie1973

Why don't you take the worse of the two brakes to your LBS and ask them to bleed/check it for you. It shouldn't cost too much and by the sounds of things is likely to save you a lot of time and wasted effort. If the shop does it successfully then you'll know that the brakes are fine and that the problem is with your attempt at bleeding. If there are problems they'll identify them for you which at the very least would give you some ammunition to ask for a refund with. If you offer to buy the mechanic a beer, he might even let you watch him do the bleed so you'll know for next time how to do it. At the end of the day you'll never be able to use your bike with confidence whilst your unsure of the integrity of the brakes.

mrmonkfinger

I've got a pair of Code levers which are pretty similar to the Juicy levers. They don't "leak air" in when bleeding. If you pull really really really hard you can get a bubble or two past the seal, but not during a normal bleed.

Something sounds wrong there.

Mrtennis

mrmonkfinger wrote:

I've got a pair of Code levers which are pretty similar to the Juicy levers. They don't "leak air" in when bleeding. If you pull really really really hard you can get a bubble or two past the seal, but not during a normal bleed.

Something sounds wrong there.

I think you go throught he same bleed process with the Code as I do with mine. It's at the point where you pull the brake lever a bit whilst actually bleeding from the lever port. Every pull on the lever and a load of air just rushes through. I know there is a leak. It's just whether to go for the lever or caliper service kit. Each cost £10 which is ok, but don't want to buy both for £20 if it's just leaking in at one end.
No one on here seems to be able to suggest or offer a good explanation as to where the leak is so I think I'm just going to go for the lever service kit

Mrtennis

bernie1973 wrote:

Why don't you take the worse of the two brakes to your LBS and ask them to bleed/check it for you. It shouldn't cost too much and by the sounds of things is likely to save you a lot of time and wasted effort. If the shop does it successfully then you'll know that the brakes are fine and that the problem is with your attempt at bleeding. If there are problems they'll identify them for you which at the very least would give you some ammunition to ask for a refund with. If you offer to buy the mechanic a beer, he might even let you watch him do the bleed so you'll know for next time how to do it. At the end of the day you'll never be able to use your bike with confidence whilst your unsure of the integrity of the brakes.

I could maybe consider this. However, I have made the rest of the bike myself and although there were bits I struggled on I managed to come through in the end. It's my project and it's probably being stubborn but I want to be able to say I did it all myself (which I had done until it came to change from v's to discs).
I am pretty sure though that having them bleed is not that cheap. Don't know if there's some way for them just to check what's wrong with them without bleeding them. I called them up this morning and described what was going on and the guy did say it sounded strange but he didn't suggest either where a leak might be. In fact, when I mentioned if there could be a leak he seemed very surprised. Like that sort of thing doesn't happen very often.
The price of buying the service kits might be the same as they would charge for bleeding them. And I'm guessing I would have to buy the service kit in the end anyway. So I'd end up paying double.
I am considering being cheeky and stopping by to speak to one of the mechanics, either with or without the bike. They have given me quite a bit of advice before for other bits I struggled with on the bike so they might do again. This however is a bit more complicated and I have a feeling that for them to work out exactly what is wrong they will want to take a look at it, which is going to cost.