Mcnninjas.co.uk

General Discussions => Bike Talk => Topic started by: Carbon_ZX6R on April 23, 2017, 12:58:04 PM

Title: finally i have a problem!!!
Post by: Carbon_ZX6R on April 23, 2017, 12:58:04 PM
long time no talk....

well the other week I took the b1h out for a spin
20 of miles in and I realise there is no back pressure on the rear brake , not sure what has happened , but the fluid looks well questionable.
need to know what I need to do to resolve it?
if its strip the calliper id rather replace it , I would say the fluid is contaminated?

any advise given would be appreciated as I need to fix this by the 1st may

(http://i1314.photobucket.com/albums/t574/blackstarracing8/Mobile%20Uploads/IMG_20170408_095414_zpsh6dvqrka.jpg)
Title: Re: finally i have a problem!!!
Post by: David W on April 23, 2017, 03:38:51 PM
Have you tried just bleeding it before pulling the caliper apart and probably creating a problem that isn't there?
Title: Re: finally i have a problem!!!
Post by: PJ on April 23, 2017, 06:57:59 PM
Agree with DW, bleed it, and use that as an opportunity to get all the old fluid out, which considering that looks like the Brembo style tube instead of a full reservoir shouldn't take long. I can't see any reason to replace the caliper?

When you say no pressure, what do you mean? The pedal goes all the way down without any resistance? Or it's hard as you would expect but you get no braking from the rear?

Title: Re: finally i have a problem!!!
Post by: Jonesy on April 23, 2017, 08:34:19 PM
Get rid of the stupid tube and get a proper brake fluid reservoir... That's your problem!
Title: Re: finally i have a problem!!!
Post by: Manic636 on April 23, 2017, 08:47:23 PM
When I ran that style of tube it was a bigger for allowing condensation to be absorbed into the fluid and needed lots of bleeding and fresh fluid..
Title: Re: finally i have a problem!!!
Post by: Carbon_ZX6R on April 24, 2017, 09:22:42 PM
I did bleed it when i put the new line on and it was perfect , never had condensation on my old one , there was the tiniest bit of pressure if i pushed the peddle all the way down but essentially nothing it wouldn't stop a spinning wheel , but was fine before...
Title: Re: finally i have a problem!!!
Post by: David W on April 24, 2017, 09:25:54 PM
They are fine for racebikes but don't have a bladder that lets them compensate for pad wear, so you get a vapour lock which prevents new fluid getting into the master cylinder.
Take the stopper out of the top of the tube and give the brake a few slow pumps and I reckon you'll be back in business.
Title: Re: finally i have a problem!!!
Post by: Carbon_ZX6R on May 01, 2017, 04:35:50 PM
Nope I tried it , didn't seem to make it any better....
Title: Re: finally i have a problem!!!
Post by: David W on May 01, 2017, 05:55:12 PM
Then its possibly got a blockage between the reservoir and the piston thats preventing fluid getting through.
Title: Re: finally i have a problem!!!
Post by: Carbon_ZX6R on May 01, 2017, 06:18:26 PM
Quote from: David W on May 01, 2017, 05:55:12 PM
Then its possibly got a blockage between the reservoir and the piston thats preventing fluid getting through.

so that fluid looks ok to you?


do I just bleed it some more?
Title: Re: finally i have a problem!!!
Post by: David W on May 01, 2017, 08:31:31 PM
You said you had no brake pedal pressure?
How are you planning on bleeding it without that?
Title: Re: finally i have a problem!!!
Post by: Carbon_ZX6R on May 02, 2017, 04:29:28 PM
Quote from: David W on May 01, 2017, 08:31:31 PM
You said you had no brake pedal pressure?
How are you planning on bleeding it without that?
Tiny tiny tiny bit if I spin the wheel it will stop it but if your rolling you don't notice it at all
Title: Re: finally i have a problem!!!
Post by: David W on May 02, 2017, 05:00:13 PM
Sounds to me like the problem is at the master cylinder end.
It wouldn't surprise me if that stupid garden hosepipe wasn't letting moisture in, and it's corroded the hole through to the master cylinder piston.  It would explain the state of the fluid too.
Those race setups are great for racing but racebikes get new fluid bled through them before every race.
Title: Re: finally i have a problem!!!
Post by: Carbon_ZX6R on May 02, 2017, 06:29:22 PM
had one on there before , and never had a problem with it , when this happened it was being stored outside under a cover , right providing that is the problem , what is the procedure?
Title: Re: finally i have a problem!!!
Post by: David W on May 02, 2017, 08:15:48 PM
Brake fluid is hygroscopic which means it absorbs water from the atmosphere.  Indoor or outdoor makes no difference.  The water will then sink to the lowest point, corroding things if its left long enough.

Not sure what the answer is.  I'd be tempted to get a big syringe, fill it with fresh fluid and push it back up through the system from the caliper end.  Obviously need to get a pot to catch the stuff coming out of the top.
Title: Re: finally i have a problem!!!
Post by: Carbon_ZX6R on May 03, 2017, 06:56:50 AM
Quote from: David W on May 02, 2017, 08:15:48 PM
Brake fluid is hygroscopic which means it absorbs water from the atmosphere.  Indoor or outdoor makes no difference.  The water will then sink to the lowest point, corroding things if its left long enough.

Not sure what the answer is.  I'd be tempted to get a big syringe, fill it with fresh fluid and push it back up through the system from the caliper end.  Obviously need to get a pot to catch the stuff coming out of the top.
I was wondering if it would be easier to just replace the m/c with a newer one and the same with the caliper?

brake line will be fine wont it? just blow the fluid through
?
Title: Re: finally i have a problem!!!
Post by: PJ on May 03, 2017, 09:37:06 AM
Don't bother with the master cylinder. Do what DW suggested, push new fluid through until you're absolutely sure it's all new fluid, then bleed it and see. If it's still lacking in pressure then I'd be dismantling the M/C end of it to check for corrosion as mentioned.
Title: Re: finally i have a problem!!!
Post by: David W on May 03, 2017, 09:59:40 AM
Quote from: Carbon_ZX6R on May 03, 2017, 06:56:50 AM
Quote from: David W on May 02, 2017, 08:15:48 PM
Brake fluid is hygroscopic which means it absorbs water from the atmosphere.  Indoor or outdoor makes no difference.  The water will then sink to the lowest point, corroding things if its left long enough.

Not sure what the answer is.  I'd be tempted to get a big syringe, fill it with fresh fluid and push it back up through the system from the caliper end.  Obviously need to get a pot to catch the stuff coming out of the top.
I was wondering if it would be easier to just replace the m/c with a newer one and the same with the caliper?

brake line will be fine wont it? just blow the fluid through
?

I wouldn't call that easier but it might work. Depends what the root cause of the problem is.
Title: Re: finally i have a problem!!!
Post by: Carbon_ZX6R on May 04, 2017, 05:54:41 AM
I only say that as I was looking to upgrade the m/c and caliper like I did think front set up anyway , can't afford brembo though this time
Title: Re: finally i have a problem!!!
Post by: David W on May 04, 2017, 06:46:40 AM
If you're changing either of those for different types/manufacturer you'll probably need a new hose anyway because of the fittings.

Why did I let myself get drawn in to another one of your chaos-brain threads where you'll just do what you wanted to do in the first place?
Title: Re: finally i have a problem!!!
Post by: Carbon_ZX6R on May 04, 2017, 07:16:27 AM
Wasn't thinking different brands persay , just newer models as my understanding is there a direct replacement ,well it's not like there is anything else to talk about on here...... Yet again I'm doing a public service....