Front brakes report and questions!

Hello Mighty Org, how fine you are all looking today (yes, I am after help!).

I thought you all might like to know that I did the brakes on the sv last night!

After completing a basic service (oil / filter, air filter & plugs change) last week (with the help of a mate), last night was brakes night (with a different mate).

The whole process took a little longer than expected, as they were pretty filthy and I think they had been neglected a little bit. Even though there was a good bit of life on the old pads, I had new EBC HH pads to fit. The calipers were just dirty and ideally needed a good strip down etc.

We didn't really have time to give them the full monty, but gave the calipers a good coating in brake creaner with the pistons fully out. But they wouldn't easily push back in - they had to be tapped back in gently.

QUESTION 1
Is this normal? If brake calipers were in tip top condition should I be able to push them in with my girl-like hands?

So, calipers on, new pads in, braided lines re-connected to the calipers. let the bledding process begin!

All was well (what would I know, I have never bled brakes before), and the bike is back together. The brakes seem better / firmer. BUT....compared to my cbr600 / cbr900, those brakes were really keen. There was a little travel in the lever, then when they bit, the lever didn't really move much after.

When braking on the sv now, the lever (set on No. 5) is at it's farthest from the handlebar. It travels a fair way till the brakes start biting. But once they bite, it still manages to travel a bit. I've not been braking with gusto yet (he's a nice guy ) as they are new pads. But I was just wondering for some feedback.

QUESTION 2
Is this normal for the front brake? Would having renthal bars make any difference? I don't like the feeling of my fingers getting trapped.

QUESTION 3
If anyone with great (i.e. better than mine) SV technical knowledge would like to come visit, and impart some knowledge my way, I will provide endless cups of tea / coffee (dolce gusto ) / biscuits / sarnies. I do have (limited) tools. Also I would appreciate an experienced sv owners eye being cast over it.

We could also tie it in with a rideout too.

Well if you got this far, thanks for reading.

[flymo]

Originally Posted by Camel

QUESTION 1
Is this normal? If brake calipers were in tip top condition should I be able to push them in with my girl-like hands?

So, calipers on, new pads in, braided lines re-connected to the calipers. let the bledding process begin!

All was well (what would I know, I have never bled brakes before), and the bike is back together. The brakes seem better / firmer. BUT....compared to my cbr600 / cbr900, those brakes were really keen. There was a little travel in the lever, then when they bit, the lever didn't really move much after.

When braking on the sv now, the lever (set on No. 5) is at it's farthest from the handlebar. It travels a fair way till the brakes start biting. But once they bite, it still manages to travel a bit. I've not been braking with gusto yet (he's a nice guy ) as they are new pads. But I was just wondering for some feedback.

QUESTION 2
Is this normal for the front brake? Would having renthal bars make any difference? I don't like the feeling of my fingers getting trapped.

QUESTION 3
If anyone with great (i.e. better than mine) SV technical knowledge would like to come visit, and impart some knowledge my way, I will provide endless cups of tea / coffee (dolce gusto ) / biscuits / sarnies. I do have (limited) tools. Also I would appreciate an experienced sv owners eye being cast over it.

We could also tie it in with a rideout too.

Well if you got this far, thanks for reading.

Hi Camel,

Sounds like you're having fun and enjoying getting your hands dirty.

The pistons should be pretty firm with properly bled brakes but yeah you should be able to press them in with your hands. Sounds like the dust seals have swelled up on yours, this is normal over time.

From what you've described I dont think the front brakes are bled fully yet then. You wouldnt expect that much movement, certainly not enough to bring the lever nearly back to the bar. The amount it travels before it applies the brakes can depend on a few things, if its a replacement lever then there may be a little more fresh air between the lever and the surface that it presses against on the master cylinder piston.

But, the lever should come back and go very firm as the brake is applied. If it doesnt then thats usually a sign that you still have air in the system.

It is a little hard to tell for definate just how much movement there is from this distance but from the way you describe it its still a little 'spongy'.

Renthal bars should make no difference at all.

Newcastle is a little far for me, maybe somebody closer can pop around. You are of course welcome to pop in if you are anywhere near the north west.

One thing thats not clear. Did you break into the lines at all or replace them or was the system left intact whilst you cleaned it?

Cheers flymo. I am loving getting the hands dirty. Just been looking at tool chest pr0n in the Halfords website!

Maybe I need a secondary bleeding session then. I could take them down to my mechanic, but that would defeat the learning process.

Thanks for the kind offer to pop over too!

[flymo]

Originally Posted by Camel

Cheers flymo. I am loving getting the hands dirty. Just been looking at tool chest pr0n in the Halfords website!

Maybe I need a secondary bleeding session then. I could take them down to my mechanic, but that would defeat the learning process.

Thanks for the kind offer to pop over too!

Well, the two most likely areas will be air in the lines up near the master cylinder or in the calipers. The first will most likely heal itself as the bike moves around and the brakes are used. When you did this was the bike on its side stand? Thinking about the way bubbles will rise, what you are looking for is an upwards path right the way to the actual reservoir. On the S model you may find it better to get a helper to unfasten the reservoir and lift it up slighty while you do this, or on a naked just tilt the bike properly on its sidestand.

Tap the lines with a spanner all along their length to shift bubbles etc.

Or the second area (especially if you took the pistons out of the calipers) is air in the calipers. That needs to be bled through the bleed nipples on each caliper. I find what works well (and I'm sure everyone will have their own way of doing this) is to get a nice long clean length of plastic tubing that fits tightly over the end of the nipple, connect the tubing to the nipple on one of the calipers and loosen it (dont press the brakes at this stage). Allow any bubbles to escape and you'll start to see just fluid. Nip up the nipple and do the same to the other side making sure you dont spill any fluid on the brake discs.

Then, if you havent felt an improvment already, go on to bleed the nipples. Pop the line on to one caliper, have an assistant squeeze the lever and keep it there. You then loosen the nipple slightly to allow fluid and hopefully bubbles through. If you see no bubbles, nip the nipple up and do the other side.

Job done.

Just got the bike up on it's stand ready for a good de-grease / clean etc, and looking at the brakes again, they are much better than previously.

However, the offer still stands if anyone wants to come over and talk SV's!

I just popped my calipers off and cleaned the pistons with brake fluid too. The front wheel turns much more easily now and the brakes seem to bite earlier although not any stronger.

Camel, you're welcome to pop down to mine in Teesside if you wish me to have a look. Sorted my brakes out with braided lines & pads and bled them myself. A tip is to pull the brake lever in and tie it to the bar overnight so that the brake is applied over night. Just leave the brake fluid res cap off, and then in the morning you can see if you can bleed anymore air from it. Mine are much better than they used to be.

Sorry, just to answer flymo, the bike was on a paddock stand while the work was being done.

rob, excuse my ignorance, but how does leaving the brake on overnight, with the res cap off help? Does it just help force the air to the bottom of the lines abit more?

[flymo]

Originally Posted by Camel

Does it just help force the air to the bottom of the lines abit more?

Other way around Camel, the idea is that the fluid in the lines is kept under higher pressure forcing air upwards to the top. I've never found this necessary really. Also, it does nothing to expel air from teh calipers, the only way to do that is bleed them at the nipple.

[flymo]

Originally Posted by Camel

Sorry, just to answer flymo, the bike was on a paddock stand while the work was being done.

Just realised what you said here....

This might be your problem initially, the bike needs to be tipped over on its sidestand if you are bleeding it by hand. Air bubbles will only travel upwards unless moving quickly under pressure with the fluid.

So imagine tracing the lines all the way to the top, they join the master cylinder and then the fluid path runs downhill (due to the handlebar angle) and then up to the reservior. By tilting the bike onto its sidestand and turning the bars fully to the left you should see that the master cylinder bore is now level or even tilted slightly in your favour, allowing the air to rise to the top. On a front paddock stand you will definatley trap an air pocket where the lines join the master cylinder.

You'll probably find just putting the bike on its sidestand and squeezing the brakes on and off for 5 mins will sort this, you should also see the fluid level drop ever so slightly.