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I just installed new brake pads yesterday, and I accidently opened the brake line which means I probably introduced some air into the system. No it doesn't catch quite as well, it brakes but it feels rough. does anyone know how to bleed the brake line? I have the Clymers manual but I'm having a hard time figuring this out. Any tips I gotta watch out for, like the hydraulic clutch or anything? My bike does not have ABS. Thanks

The front brake plumbing has an uncanny knack for trapping air, due to its many segments and twists & turns.

The only approach is to be every bit as stubborn about the brake bleeding process as the front circuit is about holding onto its entrained air. Tap the lines, use the front subframe bleeder position, flush lots of fluid, squeeze-squeeze-squeeze-hold-bleed, etc. I'm even considering a home-made pressure bleed setup just for the heck of it.

Finally, if the process drives you nuts, then you might consider a fron brake circuit changeover to "superbike" setup, with two brakes lines running directly from front brake master down to each caliper. Riceburner did this and reported easy front brake bleeds. I've been tempted ever since.

awesome, but actually is it the same for the rear brakes? This is the one that I accidently opened up the brake lines. I was thinking of buying the Mityvac 8500, I think it might come in handy for future use. What do you suggest, I definately think there is an air bubble in there. Thanks

I also forgot, do I use grease in back of the brake pads? the clymers manual told me to lightly grease the back of the pad so I used Moly grease to do so, but then another part of the book told me not to get any grease into the braking system. Should I dismantle and degrease the brakes?

Rear brake circuit is a snap due to its short length and position of bleeder valve at top of rear caliper following horizontal brake line run.

Make sure the line from reservior cup to master is leak-free and secure.

Use the "squeeze-squeeze-squeeze-bleed" method several times to push any air out the caliper.

I've never had to replace the rear pads on Roadster or Rockster, so can't comment about need for anti-squeal treatment on back of brake pad. Also have yet to experience brake squeal on these bikes after 50k+ miles accumulated on R850R, R1100R, R1150Rs, so all my new front pads have gone in dry.

My only concern about a light surface wipe with grease is tendency to pick up & hold dirt.

No need for a MityVac in my opinion, just patience when bleeding the front brake circuit.

I'm not sure what part of the brakes you are talking about greasing. I think the Clymer manual was talking about lightly greasing the holes in the pads that the holding pin passes through. Very lightly greasing those holes would be OK...just make sure no grease gets on any other parts.

The pads and the rotor MUST be grease free, the consequences of having any grease on those parts will be a totally useless brake.

The rear is a floating caliper. The whole caliper slides back and forth on lugs (one lug is on the caliper, the other is on the carrier). The lugs might need some greasing (on occasion).

Pictures courtesy of Cyclerob...

The lugs I am talking about are the gold colored shafts, see the one here protruding from the caliper


Here you can see the other on the carrier...


Each lug has a ridge at its base, to hold the rubber dust boot (expanding, accordion style) in place.

All you need to do to separate the carrier from the caliper is pull them apart (no tools needed). I would recommend that you slide the edge of the rubber boots off the ridge (before actually pulling the carrier from the caliper), to make sure you don't damage the rubber boots. The second picture explains where to apply the grease. You do not need to remove the brake line from the caliper to do all this (or remove pistons and seals).

sweatmark wrote:The front brake plumbing has an uncanny knack for trapping air, due to its many segments and twists & turns.

The only approach is to be every bit as stubborn about the brake bleeding process as the front circuit is about holding onto its entrained air. Tap the lines, use the front subframe bleeder position, flush lots of fluid, squeeze-squeeze-squeeze-hold-bleed, etc. I'm even considering a home-made pressure bleed setup just for the heck of it.

Finally, if the process drives you nuts, then you might consider a fron brake circuit changeover to "superbike" setup, with two brakes lines running directly from front brake master down to each caliper. Riceburner did this and reported easy front brake bleeds. I've been tempted ever since.

Yes I did that - unfortunately during the process I split the callipers, and had to replace them, then wrecked a resevoir thread and had to replace THAT, and now, I have very spongy brakes which will NOT firm up properly. GRARARARAR.

I have a nasty feeling that I have an ABS-type master cylinder - the brakes DO work well once a certain amount of travel of the master cylinder piston has occurred - but that "certain amount of travel" is BLOODY annoying. My thinking is that the ABS m/c has the feed hole from the resevoir in a slightly different position - to allow the electrical switch to engage before any braking force is exerted. I've yet to take detailed measurements from my old m/c to confirm this though.

Could anyone care to comment on this??
If so I will be very irritated because getting hold of a 2nd hand non-abs m/c, and confirming it as such, will be an absolute nightmare.

deathtriforce wrote:awesome, but actually is it the same for the rear brakes? This is the one that I accidently opened up the brake lines. I was thinking of buying the Mityvac 8500, I think it might come in handy for future use. What do you suggest, I definately think there is an air bubble in there. Thanks

On a NON-ABS bike the two (sorry, 3 - including clutch) hydraulic circuits are totally seperated - they don't even share resevoirs.

I have a nasty feeling that I have an ABS-type master cylinder

From what I could gather while preparing for iABS removal, the front brake masters for ABS and non-ABS were identical, with exception of the respective brake switches. Piston diameter is same, but I did not confirm this fact via disassembly.

The rear brake masters for ABS and non-ABS have different piston diameters, with ABS being 1-2mm smaller, IIRC.

Once my Rockster was un-ABS'd and front brake circuit bled (several times), I tried to compare the braking performance of Rockster and our non-ABS Roadster "by feel", and perceived no difference. There's some free travel in the brake lever before braking force is applied, not exactly "slop", but not the immediate engagement that's customary for a sport bike or my Buell XB for example. I don't mind the progressive braking of the Evo calipers and front brake master, as long as those brakes really perform when the lever is halfway through its travel.

OK I think I figured out the problem to all the spongyness. When I went back and took apart my brakes, I hit the rear brakes to see what it did and to my surprise only one of the pistons rose up. Does this mean I gotta redo the calipers and pistons? I guess there's more than meets the eye

It would not be unusual for only one piston to move. Actually, it is most likely only one piston would move. Try holding the piston that moved (or block its movement with something solid), and the next time you pump...the other should extend. While you are at it, extend both pistons a bit (not so far that they fall out). Scrub the crud off the piston with a toothbrush and clean brake fluid for a solvent. Now you can take pride in your clean pistons, and have the assurance that your seals won't be leaking.

The Mityvac is a fine tool...it will make life easier.

Rather than typing out another bleed instructional, below is a link. Once you are there...go down and click the link under the "Brakes" section that says: Bleeding IBMWR...

The instruction is for r1100 bikes. The method is exactly the same. I would add this bit of intstruction though...

Before bleeding, Push both pistons (or all 8 in the case of the front brakes) fully into the caliper (don't overflow the master cylinder!)...and put a block of wood in the caliper(s) to keep the pistons in the fully retracted position. This will make sure that any air in the caliper (and ALL of the old fluid) is not "hiding out".

After the pads are put back in, and the caliper(s) is on the bike, squeeze the brakes several times to push the pads squarely against the rotor, and then make a final check on the fluid level.

http://home.mindspring.com/~jabrooks/

sweatmark wrote:

I have a nasty feeling that I have an ABS-type master cylinder

From what I could gather while preparing for iABS removal, the front brake masters for ABS and non-ABS were identical, with exception of the respective brake switches. Piston diameter is same, but I did not confirm this fact via disassembly.

The rear brake masters for ABS and non-ABS have different piston diameters, with ABS being 1-2mm smaller, IIRC.

Once my Rockster was un-ABS'd and front brake circuit bled (several times), I tried to compare the braking performance of Rockster and our non-ABS Roadster "by feel", and perceived no difference. There's some free travel in the brake lever before braking force is applied, not exactly "slop", but not the immediate engagement that's customary for a sport bike or my Buell XB for example. I don't mind the progressive braking of the Evo calipers and front brake master, as long as those brakes really perform when the lever is halfway through its travel.

Yeah - that's the free travel I'm talking about - I HATE it. I like to be able to graze the disc with a tiny movement of one finger - now I have to grab the whole lever with all my fingers to get any decent braking - if I don't the lever travel will trap my 3rd and last fingers and prevent full braking. On the old system I could, and DID do stoppies with 2 fingers. My old m/c did NOT have that free travel, which is why I think I've either got a ABS m/c, or something else is wrong.

Rice,

With Sweatmark's experience, I don't think the issue is an ABS master. You might have an air bubble trapped at the top of the brake line (right near the banjo fitting). Bleeding this bubble out throught the bleed nipple on the caliper is nearly impossible. I've unsuccessfully tried, many many times, on a previous bike I owned. I know the frustration.

Have you done the LEAN IT WAY OVER TO THE LEFT method?

It works if there is just a small bubble. This is much easier with a second person. But the idea is to lean the bike far to the left side, since the bubble will tend to migrate upwards in the fluid. Then slowly squeeze and release your brake many times. This will get the air to come up through the tiny bleed-back hole. Only a very small amount of air will come out each time the lever is squeezed.

If there is a larger bubble...another way is to slightly loosen the banjo fitting (Just a tidge). Then you can push the air out by squeezing the brake lever. It works best if you squeeze the lever first to build pressure...then open the banjo bolt...you will feel the air getting pushed out. Once the air is squeezed out... and still holding the lever...tighten the banjo. Then, it would be advised to do the Lean IT Way Over method to remove any tiny amount of air still in there.

P.S. this works on the clutch too...it is the LEAN IT WAY OVER TO THE RIGHT method.

do you guys know if a really bad rotor will cause the spongy stop as well?

iowabeakster wrote:Rice,

With Sweatmark's experience, I don't think the issue is an ABS master. You might have an air bubble trapped at the top of the brake line (right near the banjo fitting). Bleeding this bubble out throught the bleed nipple on the caliper is nearly impossible. I've unsuccessfully tried, many many times, on a previous bike I owned. I know the frustration.

Have you done the LEAN IT WAY OVER TO THE LEFT method?

It works if there is just a small bubble. This is much easier with a second person. But the idea is to lean the bike far to the left side, since the bubble will tend to migrate upwards in the fluid. Then slowly squeeze and release your brake many times. This will get the air to come up through the tiny bleed-back hole. Only a very small amount of air will come out each time the lever is squeezed.

Not tried this

iowabeakster wrote: If there is a larger bubble...another way is to slightly loosen the banjo fitting (Just a tidge). Then you can push the air out by squeezing the brake lever. It works best if you squeeze the lever first to build pressure...then open the banjo bolt...you will feel the air getting pushed out. Once the air is squeezed out... and still holding the lever...tighten the banjo. Then, it would be advised to do the Lean IT Way Over method to remove any tiny amount of air still in there.

Yup, I know all about that trick Done that a couple of times - no joy. Have to say its really frustrating as I had the same 2 line setup on my ZXR400 and I genuinely had 2-finger stoppie brakes.

iowabeakster wrote: P.S. this works on the clutch too...it is the LEAN IT WAY OVER TO THE RIGHT method.

Have to admit - I've never touched the clutch on either of my bikes.... it just keeps working fine.

deathtriforce wrote:do you guys know if a really bad rotor will cause the spongy stop as well?

Yes - it can do. A warped rotor will kick the pistons back into the caliper body more than normal - meaning you need to push the pistons out further than normal each time you hit the brakes.

normally though, a warped disc can be felt as slight pulsing through the lever during braking.