SV650.org - SV650 & Gladius 650 Forum



SV Talk, Tuning & Tweaking Discussion and chat on all topics and technical stuff related to the SV650 and SV1000
Need Help: Try Searching before posting

Reply
 
Thread Tools
Old 22-06-18, 02:30 PM   #21
Bibio
Member
Mega Poster
 
Bibio's Avatar
 
Join Date: Jul 2008
Location: here as devil's advocate
Posts: 11,539
Default Re: Bleedin' Brakes

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.
Bibio is offline   Reply With Quote
Old 25-06-18, 07:13 AM   #22
kbh
Member
 
Join Date: Feb 2009
Location: Crowborough
Posts: 69
Default Re: Bleedin' Brakes

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
kbh is offline   Reply With Quote
Old 25-06-18, 08:17 AM   #23
R1ffR4ff
Member
Mega Poster
 
R1ffR4ff's Avatar
 
Join Date: Feb 2017
Location: JAMOADR(1999 Curvy) 36,000 miles
Posts: 1,427
Default Re: Bleedin' Brakes

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
__________________
"Stultus est sicut stultus facit"
R1ffR4ff is offline   Reply With Quote
Old 25-06-18, 08:39 AM   #24
kbh
Member
 
Join Date: Feb 2009
Location: Crowborough
Posts: 69
Default Re: Bleedin' Brakes

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
kbh is offline   Reply With Quote
Old 25-06-18, 09:54 AM   #25
Talking Heads
Member
 
Join Date: Jan 2017
Posts: 486
Default Re: Bleedin' Brakes

Were the bobbins seized on the old discs?
Talking Heads is offline   Reply With Quote
Old 25-06-18, 10:08 AM   #26
kbh
Member
 
Join Date: Feb 2009
Location: Crowborough
Posts: 69
Default Re: Bleedin' Brakes

nope they all freely turned by hand
kbh is offline   Reply With Quote
Old 25-06-18, 08:46 PM   #27
Red Herring
Member
Mega Poster
 
Red Herring's Avatar
 
Join Date: Dec 2007
Posts: 2,708
Default Re: Bleedin' Brakes

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.
Red Herring is offline   Reply With Quote
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Bleedin' Brakes! Grinch SV Talk, Tuning & Tweaking 54 03-07-08 10:53 PM
Bleedin Brakes!! and Heat shrinking and.. ejohnh SV Talk, Tuning & Tweaking 10 16-02-08 03:01 PM
Bleedin' Brakes! Phantomtek SV Talk, Tuning & Tweaking 4 17-03-07 09:35 PM
The Bleedin' Brakes! snoopy SV Talk, Tuning & Tweaking 29 16-04-05 04:49 PM
Bleedin salt! shutdown SV Talk, Tuning & Tweaking 2 28-02-05 11:58 AM


All times are GMT. The time now is 07:10 AM.


Powered by vBulletin® - Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.