Most motorcycle problems are caused by the nut that connects the handlebars to the saddle.

Front brake issues

Share
avatar
Wildwards
Godly
Godly

Awesome!
Posts : 69
Location : Northants

Front brake issues

Post by Wildwards on Wed 08 Oct 2014, 7:30 pm

This is a bit long winded but any help greatly appreciated. Probably really basic stuff for many.

I noticed uneven wear and a bit of a grinding noise from the front caliper (nissin) so got some new pads. On inspection the caliper was heaving and the pistons jammed solid. The pin wouldnt come out to get the old pads off but the spring just fell out so I didnt notice where it was supposed to go on reassembly. So I've removed the caliper, gave it a good clean, got the pin, pads and pistons out, cleaned them and replaced with new seals. and all the relevant bits regreased and new pads in Its now tip top and I was quite chuffed at the time. 
On reassembly though I wasnt sure if the spring was in the right place. I placed it in the recess with the v facing down and the flat edge of the spring nearest the pin. It was a bit of a faff which didnt fill me with confidence. Anyway, the caliper is back on but all is not well as I'll come to.
I`ve bled the brake using gravity and started by just slowly pumping the front brake until no more air bubbles appeared in the master cylinder and I started to get some pressure building. I then turned to the caliper and used the lever in, open bleeder screw, close bleeder screw, let out lever method. No air bubbles that I could see but not much more pressure building on the lever either. I hadnt been doing that long. Thought I`d try it any way. Hopeless. Theres a clicking noise coming from the pad area when I pull the lever so somethings happening but no where near enough, and it doesnt sound like things are right down there and I can only put it down to the spring. Theres no fluid leaking from anywhere so....
Can someone tell me the correct positioning for the pad spring?
and do I just keep on bleeding until pressure builds or am I doing something wrong? I have a feeling I have the bleeding technique wrong.
avatar
Stooby2
Godzilla
Godzilla

Posts : 238
Location : Croydon, Sarf Laaandan

Re: Front brake issues

Post by Stooby2 on Wed 08 Oct 2014, 7:49 pm

Try doing the bleeding procedure, but undo the banjo bolt that connect the brake hose to the master cylinder instead of the bleed nipple Sometimes air gets stuck there and just won't go down the brake hose to get bled out normally. I had the exact same issue and this cured it.
avatar
Tricky.
the 900
the 900

Posts : 721
Location : Derby

Re: Front brake issues

Post by Tricky. on Wed 08 Oct 2014, 7:51 pm

put a pipe on the bleed nipple and crack the nut off, make sure the other end of the pipe is immersed in brake fluid. pump the brake lever till the fluid has gone down to the half way mark on the master cylinder, refill and repeat a few times, and/or until no air bubbles.
avatar
Wildwards
Godly
Godly

Awesome!
Posts : 69
Location : Northants

Re: Front brake issues

Post by Wildwards on Wed 08 Oct 2014, 7:58 pm

Tricky. wrote:put a pipe on the bleed nipple and crack the nut off, make sure the other end of the pipe is immersed in brake fluid. pump the brake lever till the fluid has gone down to the half way mark on the master cylinder, refill and repeat a few times, and/or until no air bubbles.
Thanks Tricky, I shall give that a go too.
avatar
jonny10
the 900
the 900

Awesome!
Posts : 301

Re: Front brake issues

Post by jonny10 on Wed 08 Oct 2014, 10:56 pm

Have a look here

http://www.youtube.com/watch?v=b4yyLDaYBLI
avatar
Wildwards
Godly
Godly

Awesome!
Posts : 69
Location : Northants

Re: Front brake issues

Post by Wildwards on Thu 09 Oct 2014, 7:32 am

Ok thanks jonny. I have a few options there.

I think I may have the pad spring upside down too. I`m looking at the pic in the haynes and it looks like it goes in with the bend up rather than down in the recess? Does it just sit there or does it clip in?
avatar
jonny10
the 900
the 900

Awesome!
Posts : 301

Re: Front brake issues

Post by jonny10 on Thu 09 Oct 2014, 11:37 am

I found this thread helpful when doing mine - particularly post 11 onwards


http://www.cb500club.net/t144-pad-plate-on-front-brake-disc?highlight=pad+spring


Last edited by jonny10 on Thu 09 Oct 2014, 11:39 am; edited 1 time in total (Reason for editing : correct wording)
avatar
jonny10
the 900
the 900

Awesome!
Posts : 301

Re: Front brake issues

Post by jonny10 on Thu 09 Oct 2014, 12:04 pm

If your having trouble getting air out, have a look at this - go to 11:37

http://www.youtube.com/watch?v=F2vLLC4iC78
avatar
eternally_troubled
Admin
Admin

Awesome!
Posts : 3656
Location : 'ere be fens. (near Cambridge)

Re: Front brake issues

Post by eternally_troubled on Thu 09 Oct 2014, 1:02 pm

All good advice. I generally find that it is helpful to use a properly clean container to catch the brake fluid that comes out of the bleeding pipe, then you can just pour it back into the top of the system and carry on.

In this way you can use a (relatively) small amount of brake fluid carefully pumped through a good few times to remove as much air as possible. Some of the bubbles can be really small (sub 1mm diameter).
avatar
Wildwards
Godly
Godly

Awesome!
Posts : 69
Location : Northants

Re: Front brake issues

Post by Wildwards on Thu 09 Oct 2014, 1:13 pm

Ok thanks all, I think I have enough to go on re the bleeding. A great help.
Am still a little unsure about positioning of the pad spring though as in the thread advised by jonny is he talking about a nissin or brembo? Mine's a nissin. 

If its not raining when I get home from work I`ll whip the pads out and try it both ways, or even all four ways! Hopefully I won't have to take the caliper back off!
avatar
eternally_troubled
Admin
Admin

Awesome!
Posts : 3656
Location : 'ere be fens. (near Cambridge)

Re: Front brake issues

Post by eternally_troubled on Thu 09 Oct 2014, 1:17 pm

Good luck with the spring.

My bike has the Brembo caliper so I can't help. Have a look at this diagram:

http://www.lingshondaparts.com/honda_motorcycle_parts_selection_pfk.php?block_01=13MY5R41&block_02=F__0900&block_03=1542

It seems to show the spring in a particular orientation - good luck!
avatar
Wildwards
Godly
Godly

Awesome!
Posts : 69
Location : Northants

Re: Front brake issues

Post by Wildwards on Thu 09 Oct 2014, 1:30 pm

Thanks eternally
yes I`ve definitely got it upside down then. its hard to tell from the Haynes as the picture is taken from directly above and I went for the logical way (to me) which was putting the valley of the spring into the recess in the caliper.

I think my bikes a bit of a mish mash. Its an M plate registered in 94 but its got original silver paint which didn't come out until 98 I think. Its got a nissin on the front and a brembo on the back. Must have had a few changes done on it over the years.
avatar
Wildwards
Godly
Godly

Awesome!
Posts : 69
Location : Northants

Re: Front brake issues

Post by Wildwards on Fri 10 Oct 2014, 12:26 pm

Ok so its sorted.
For anyone who comes across the pad spring location problem on a nisssin front caliper, the spring is a shallow V-shape. It goes in inverted so the peak is facing up and sits with the straight edge of the spring  over the edge of the rectangular recess nearest the middle of the caliper so the peak of the spring peaks in between the two pistons. It doesn't really clip in but it does seat quite naturally and when you get it it seems obvious (another Doh! moment)

Oh by the way, if anyone needs a pad plate for a nissin front caliper I have a spare as I bought one thinking it had been lost as there was so much mank on the caliper and bracket it was buried under filthy grease and I couldn't see it.

As for the bleeding, I had another go at it last night and it wasn't great so I tied the lever back against the handlebar and left it over night to allow any air to rise and gave it a few pumps through this morning Just been out for a spin and all is well. Little bit of pad rub but I expect that with new pads and they will bed in. Brakes aren't rock solid but they stop well enough.

Thanks all for the advice.
avatar
Tricky.
the 900
the 900

Posts : 721
Location : Derby

Re: Front brake issues

Post by Tricky. on Fri 10 Oct 2014, 6:55 pm

eternally_troubled wrote:I generally find that it is helpful to use a properly clean container to catch the brake fluid that comes out of the bleeding pipe, then you can just pour it back into the top of the system and carry on.

In this way you can use a (relatively) small amount of brake fluid carefully pumped through a good few times to remove as much air as possible.  Some of the bubbles can be really small (sub 1mm diameter).
be careful of reusing the pumped though brake fluid straight away, if it has air in it all you will be doing is putting fluid with air in straight back into your system. reuse the good/new pumped brake fluid another day when it has settled and got rid of the bubbles itself.
avatar
jchesshyre
the 900
the 900

Posts : 636
Location : Chester

Re: Front brake issues

Post by jchesshyre on Fri 10 Oct 2014, 8:09 pm

Also, for future reference, gently tapping the various fittings in the brake system with a hammer (GENTLY) can help dislodge bubbles.

I had a CB with a Nissin caliper for a few years and have recently replaced it with a later model with a Brembo one. I don't know if it's just luck or coincidence, but it used to take me about twenty minutes of bleeding to get firmness in the lever on the Nissin system, while on the Brembo it takes about a quarter of the time. I did it loads on the old bike and have done it twice on the new one, so I'm thinking there's some design issue that means bubbles are much harder to displace on the Nissin system.
avatar
badseeds
Moderator
Moderator

Awesome!
Posts : 1792
Location : Beccles, Suffolk

Re: Front brake issues

Post by badseeds on Fri 10 Oct 2014, 8:24 pm

jchesshyre wrote:I had a CB with a Nissin caliper for a few years and have recently replaced it with a later model with a Brembo one. I don't know if it's just luck or coincidence, but it used to take me about twenty minutes of bleeding to get firmness in the lever on the Nissin system, while on the Brembo it takes about a quarter of the time. I did it loads on the old bike and have done it twice on the new one, so I'm thinking there's some design issue that means bubbles are much harder to displace on the Nissin system.

Your mileage may vary. It didn't take me that long to bleed my Nissin set-up ('06 CB600F Hornet offside caliper and '08 CBF500 master cylinder) and I never had issues bleeding 'em up. My spannering skills would be classed as basic. Perhaps just having a refresh was enough.
avatar
ashcroc
the 900
the 900

Awesome!
Posts : 1505
Location : London

Re: Front brake issues

Post by ashcroc on Sat 11 Oct 2014, 7:26 am

You may find it easier to reverse bleed the system.
It has the benefit of sending the air in the system the way it naturally wants to go.

Sponsored content

Re: Front brake issues

Post by Sponsored content


    Current date/time is Thu 21 Sep 2017, 6:32 pm