Another brake question.

Evil636 · April 05, 2015, 09:00:41 PM

Hi people. I've not posted in God's knows how long but im here anyway and need some advice. Zx6r B1h front brakes. I've rebuilt the master cylinder and got hold of a pair of 04/05 zx10r refurbished calipers. Put everything back together including the little plates on the back of the pads to stop squealing etc and filled the system and got rid of all the air etc but im not getting any decent pressure in the lever. There's no air trapped and no leaks but it just doesn't seem to firm up. I've left it for the night but have i missed something or am I just driving myself crazy. Cheers for any info guys.

ash · April 05, 2015, 11:59:55 PM

Trust me, there is still air in the system.

Get one of these large animal syringes from a friendly vets, fill it with clean brake fluid and back bleed from the caliper...push the fluid from the caliper up to the reservoir(make sure all the pistons are fully home in the caliper first and start with the left caliper first). Once you have pushed any bubbles into the reservoir, then draw the fluid back down into the syringe. Start with the caliper furthest away.

Push and pull a few times and you should get it sorted

Evil636 · April 06, 2015, 05:26:55 AM

Cheers fella. I will give it a go later. I could swear I'd got rid of all the air but will give this a try.

the invisible dog · April 06, 2015, 05:24:07 PM

Red rubber grease on the seals sorted my 04/05 10R brakes

They weren't useles but the lever would come back to the bar
Stripped. cleaned and bled repeatedly after reassembling with just fluid, as the manuals instruct, but never got any better
Was very close to splashing out on Brembo master and swapping the callipers but thought I'd try the grease...
£4 well spent - lever like a micro switch now

ash · April 06, 2015, 08:34:52 PM

I'd not refurbish a set of calipers without the red grease now. Next step after the Tokico's is swapping to monoblocs. Pads are also less than half the price as well.

Carbon_ZX6R · April 06, 2015, 08:45:46 PM

Gota love a set of monoblocs!

Evil636 · April 12, 2015, 10:40:13 PM

Well I tried the syringe method. Some air came up but not loads. I cracked each banjo to make sure no air was trapped around them. Even bought a vacuum pump and pumped the fluid round under pressure in a variety of positions to allow any air to flow up down etc and still I pump the lever and im getting no pressure. I'm at a total loss now to the point where I will get the local garage to fetch it and sort it for me but being a guy that's stripped calipers before and never had this amount of trouble im reluctant to give in and admit defeat.

ash · April 12, 2015, 11:17:33 PM

Did you dig the pads out and push all the pistons completely home before bleeding again ?

Evil636 · April 12, 2015, 11:43:36 PM

Yep. Tried everything possible fella. Pushed pads back and pumped the pistons back out, which confused me because I can pump the pistons out and they all move you can see them pumping out but there's no pressure whatsoever.

Carbon_ZX6R · April 13, 2015, 06:23:04 AM

hmmmmm very curious

ash · April 13, 2015, 11:10:40 AM

Quote from: Evil636 on April 12, 2015, 11:43:36 PM
Yep. Tried everything possible fella. Pushed pads back and pumped the pistons back out, which confused me because I can pump the pistons out and they all move you can see them pumping out but there's no pressure whatsoever.

Silly question, did you touch the MC seal ?

Evil636 · April 13, 2015, 12:05:42 PM

If you mean touch it when rebuilding then yes.

ash · April 13, 2015, 12:47:02 PM

Is there a chance that the MC seal went on back to front ?

Another thing was putting my new brake lines in. They are amazing, but this bend in union by the MC managed to trap a couple of bubbles. Try removing the MC from the bar, orientate it whilst back bleeding and see if you have any pockets still.

Can't be anything but air unless the MC has been reassembled incorrectly.

1-600-matt · April 13, 2015, 12:58:48 PM

Over winter I rebuilt the stock callipers on my b1, the seals looked ok but the it's seals weren't looking great. I cleaned it all up and put them back together with the old seals. It bled through but wasn't as firm a lever as I expected, also the pads were dragging on the discs a bit too much. So I got a set of dust and oil seals and rebuilt the callipers with new seals, now the lever is solid and brakes are awesome. Did you put new seals in the callipers?

Evil636 · April 13, 2015, 05:41:19 PM

It was a fully refurbished set of calipers so new sells yes. I have had the whole system off the bike now still attached together in the hope that I could expel any air bubbles but to no avail. The seals were assembled right I can assure you of that fellas but I've taken the system to my garage off the bike and they are going to look at it for me.