Front brakes rubbing

[Guest highboy_coupe]

Hello,

 

I recently replaced all my front pads, I noticed when I put them in it was a bit of a job to push them up into the caliper even when pushing the caliper from the opposite side to open them up. Now I get a constant whirring/rubbing sound and it is harder to push around. Everything seemed pretty clean in there whan I put the new pads in, although the LH pads were worn right down.

Are these calipers like car ones, where I can pull the knuckle off and grease the pins and clean around the pistons, or is it more difficult than that?

 

Also when it's on the centre stand, If I pull in the front brake, nothing much happens at the back, isn't it supposed to work that way too? (the back successfully puts the front on)

 

Cheers.

[Maintenanceman 206]

First, did you open the lid of the brake fluid reservoir?

If you push the pistons back in, there must be enough space for fluid to go back, if someone have filled the reservoir you are in trouble when you just push back the pistons.

One case here was one Yamaha V-Max what was in some shop just for brake pad change, they didnt empty the fluid and it caused front wheel to lock after few km drive, speed was some 50 - 60 km/h and the bike was "gone" driver had some road rush but if the speed would be higher he might get killed.

If you want to clean the calibers you have to push out the pistons, clean them and calibers and put all back together using new seals (if you want to do it right) ok, old seals might go but it is not so big thing to change them.

After this you have to bleed the brake system properly.

There are no sliding pins like in some car brakes.

One thing what causes brakes to drag are bad brake hoses, i know few cases that brake hose have gone bad inside and caused trouble.

You have to push the front suspension down if you want the "hand" brake effect to the rear.

[Guest highboy_coupe]

Thanks,

I didn't loosen the master cylinder top, there is a visible gap at the top of the sight glass so it wasn't filled to the top. I usually loosen the cap on other bikes, the X11 manual didn't say to do this though, so I followed it (blindly!).

Should I start again and push the pistons back with the top off?

Is there no way to give the calupers/pistons a clean without popping the pistons all the way out and bleeding the system? I don't really feel confident doing that!!

Thanks again

Grahsm

[fast_eddy 712]

You could loosen the bleed nipples until it just weeps out.

 

It's a good move to change the fluid every few years, so get someone to sort it for you.

[Guest highboy_coupe]

You could loosen the bleed nipples until it just weeps out.

When pushing the pistons back in to grt the new pads in? Sorry, I wasn't sure what bit you were answering.

On my old bike I just pumped the pistons out about half way then used brake cleaner and a toothbrush to get the crap off before pushing them back in with the csp of the master cylinder. Is this kind of thing not advisable here?

I would like to give it a go but I dont want to mess it up and have to pay a dealer to bleed the whole linked system.

[fast_eddy 712]

When pushing the pistons back in to grt the new pads in? Sorry, I wasn't sure what bit you were answering.

 

 

 

Yes, it's just an alternative to loosening the cap, the displaced fluid has to go somewhere. By loosening the brake nipples that fluid doesn't go all over your handlebars and controls.

 

One thing you don't want to economise on is your brakes, the problems you are having sounds like they need attention. Brake fluid has a very limited lifetime, it absorbs moisture and contaminants over time. This degrades the seals and brake pipes.

 

I'd bite the bullet and get them properly checked out, new fluid and properly bled with a pressurised bleeder by someone who knows what they are doing.

[fast_eddy 712]

Just my own personal thoughts when fitting new pads etc....

 

I'm really not a fan of pushing the fluid backwards through the system at all, all the sh*t gets flushed back with it, with the potential to block the system. Given the x11 has 3 master cylinders plus a PCV and all sorts of other bollox on it, I'd really not do it!

 

On some cars with ABS brakes doing this can fu*k the ABS unit, Mitsubishi Shoguns/Pajeros do it all the time when DIY owners fit new pads and just push the pistons back, this requires a new ABS unit and you can guess how much money and work that involves.

 

So don't do it, just loosen the bleed nipples and let the excess fluid escape.

[Guest highboy_coupe]

Cool, I'll give it a go then see if I can find someone to check it out. According to the last owner the brake fluid has just been changed recently, but the pads were quite worn down, so I'm not sure if any garage would just do the fluid without replacing pads??

 

Thanks

[blueboy 138]

Sounds to me like the last owner may have known there was a problem and maybe thought he change the fluids and than the pads if cured but still had same problem because the mech. didn't understand the system he was working on.For safety sake I would find a good mech. thats knows about the system,if you have a good bike tyre depot in your area  they may know someone as ex police mechs.are known to them?

[Guest highboy_coupe]

Well, took the pads out and pushed the pistons out, cleaned a load of caked on brake dust, mud etc. out with a few old toothbrushes (18p for 2, Sainsburys) and rubbed the pistons till everything was shiny and clean. Pushed the pistons back in with the bleed nipple open a touch and put the pads back in, this time they slipped back in easy.

It is better now, with the front wheel off the ground I can spin the wheel but it stops after 1 revolution, there is no real resistance but there is still a whirring metallic noise. This is the same on my car incidentally. I didn't notice any noise when the pads were worn down.

I noticed the lower piston in the left hand side caliper has some pitting to it so I might have to bite the bullet and get new pistons and seals put in.

Anyone know a good independant Honda bloke near Stratford upon Avon? ??

[Guest highboy_coupe]

Ok then I suppose I am going to do this myself.

 

Looking on Wemoto http://www.wemoto.com/bikes/honda/cb_1100_sfy_sf1_x11/00-03/

 

There are three different piston sizes, small medium and large, is this because the rear uses a different size again from the two front caliper pistons?

 

SO does a front caliper have:

 

2 large and 1 small,

2 medium and 1 small,

OR 2 large and 1 medium??

 

I was thinking go for the stainless, unless someone thinks otherwise?

 

Thanks

[Guest highboy_coupe]

To answer my own question, all three are dfferent sizes, for reference:

 

Top: 25X35

Middle: 22X27

Bottom:  22X35

 

So the top one is just longer than the bottom one, rather than being different diameter, not sure why.

 

I'm going to rebuild the caliper as the front left is still dragging.

[x11r 386]

Strip the calliper first , its possible that you have got corrosion under the wiper seal and this causes the seal to grip the pistons , they may just need a good blow out then polish the seal grooves with some fine scotch brite .

Then rebuild with new seals , I would do all the callipers though. 

[Guest highboy_coupe]

Thanks fpr the info,

I can definately see pitting on the lower piston, I'm not sure it will polish out.