I Need Some Serious Advice

yea what he said

[jambo]

Originally Posted by Baph

That's a pretty big "if" there kwak And in that particular example, because brake fluid doesn't just disappear, I'd personally dump the fluid & replace the lines (with braided ones obviously) & then put the fluid back & bleed. But that's just me assuming that the lines have deteriorated.

That is messing with them, and leaves more chance of air in the system.

OK Lads I think we might be jumping the Gun a little. It's entirely possible that the fluid isn't leaking out of anywhere. As brake pads wear they become thinner and the pistons move further out, 4 pistons moving out means more fluid is needed in the callipers to fill the gap, this is topped up from the reservoir (hence why it's there).

Obviously if your fluid drops overnight you've got an issue, but in this case I think it's possible that the level has dropped over time. Check the pads are OK and top up as required, but obviously have a damn good check for any fluid leaking from the joins.


HTH

Jambo.

[Viney]

Just remember. Brake fluid is also an indication on how your brake pads are doing. If there are no leaks, then there should be enougth fluid in the Resivour(I can never spell that word) to last a set of pads, soooooo, you may need new pads.

[jambo]

Originally Posted by Baph

Put more fluid in, increase the pressure in the system when the brakes are applied, and possibly open a split up even more, rupturing it properly & dumping all the fluid on the floor, meaning no brakes.

More brake fluid in the reservoir will not increase the pressure in the system. The Master cylinder provides pressure, the reservoir is at 0 pressure (gravity aside) and merely tops up when needed

Originally Posted by jambo

OK Lads I think we might be jumping the Gun a little. It's entirely possible that the fluid isn't leaking out of anywhere. As brake pads wear they become thinner and the pistons move further out, 4 pistons moving out means more fluid is needed in the callipers to fill the gap, this is topped up from the reservoir (hence why it's there).

Obviously if your fluid drops overnight you've got an issue, but in this case I think it's possible that the level has dropped over time. Check the pads are OK and top up as required, but obviously have a damn good check for any fluid leaking from the joins.


HTH

Jambo.

All very true, but considering my service schedule, pad wear would be the last thing on my mind, they get checked every 8 weeks or so anyway. So yup, I ommited that by accident as it's just something that wouldn't happen with my bike.

EDIT: Jambo, ok, you have Xcc's of brake fluid and hit the brakes, you get a given amount of pressure applied to the discs by the pads, because of hydraulic pressure. Put more fluid in the system, and assuming you stand on the brakes just as hard (and the quality of the fluid is the same), the master cylinder would apply more pressure to the discs via the pads. I've definitely proven this to be the case with other hydraulic systems, so I don't see why brakes would be different, but happy to be corrected (internals of the master cylinder perhaps?).

Originally Posted by jambo

OK Lads I think we might be jumping the Gun a little. It's entirely possible that the fluid isn't leaking out of anywhere. As brake pads wear they become thinner and the pistons move further out, 4 pistons moving out means more fluid is needed in the callipers to fill the gap, this is topped up from the reservoir (hence why it's there).

Obviously if your fluid drops overnight you've got an issue, but in this case I think it's possible that the level has dropped over time. Check the pads are OK and top up as required, but obviously have a damn good check for any fluid leaking from the joins.


HTH

Jambo.

hey thats clever never give that a thought

Originally Posted by fizzwheel

If it were my bike I'd be concerned where the brake fluid was going, unless the fluid is two years old and never been changed either...

Ermm i dont know, i bought my bike last year from D&K motors in stoke. . . it will be a year old to me next weekend actually,
i imagine that they would of made sure everything was tip top on it when i bought it?

[jambo]

Originally Posted by lylej

Ermm i dont know, i bought my bike last year from D&K motors in stoke. . . it will be a year old to me next weekend actually,
i imagine that they would of made sure everything was tip top on it when i bought it?

A year's quite a long time for a bike being used regularly, the service schedule is every 3,500 - 4,000 miles. I'd drop it in somewhere for someone to give it a good checking over, things can wear and deteriorate over time without you noticing. If a bike fails on the move it can be worrying at best and possibly dangerous so not worth taking a chance on

Jambo

[jambo]

Originally Posted by Baph

EDIT: Jambo, OK, you have Xcc's of brake fluid and hit the brakes, you get a given amount of pressure applied to the discs by the pads, because of hydraulic pressure. Put more fluid in the system, and assuming you stand on the brakes just as hard (and the quality of the fluid is the same), the master cylinder would apply more pressure to the discs via the pads. I've definitely proven this to be the case with other hydraulic systems, so I don't see why brakes would be different, but happy to be corrected (internals of the master cylinder perhaps?).

You are assuming that more fluid enters a fixed volume system. This would mean there was pressure before you pulled the lever. If the pistons have moved out the fluid has filled up the space, meaning more fluid fills the (now larger) system at the same pressure (0). When the master cylinder is applied a certain extra pressure is applied, assuming the fluid cannot be compressed the pressure will go up by the same amount regardless of the volume in the system.

Jambo

[Luckypants]

Originally Posted by lylej

Ermm i dont know, i bought my bike last year from D&K motors in stoke. . . it will be a year old to me next weekend actually,
i imagine that they would of made sure everything was tip top on it when i bought it?

Very unlikely from my knowledge of DK. Fine for new bikes, a bit iffy for 2nd hand. They often pass the bike on exactly as it came in.