BRAKE UPGRADE advice wanted
- Thread starter Loz
- Start date
tarka said:
But it has changed.The initial push of fluid now has two seperate escape routes - but with only the same amount of fluid that needs to be moved.
It's the only difference/alteration in the system.
Steptoe said:
Fair enough....it`d need a volumetrics expert to give a definate answer,but if that is the only change,and reading about the trip that Loz did,plus the trying out of a different master cylinder,then maybe it`s worth repiping the system.
For what it`s worth,my 1150/1100 is fine with a long hose to the right caliper and a link hose from right caliper to left caliper.....although I`m still using ABS.....so Loz could perhaps just get one of the long hoses shortened and copy my system.
Number 6
Registered user
If the hoses are in good condition and not swelling then I am not seeing your logic with the 2 long hoses v 1 long 2 short hoses. The master cylinder will displace a given volume of fluid. If it is a closed system you will get the same amount of fluid displacing the slave cylinders at the calapiers no matter what amount of hose is inbetween.
That's correct in theory but don't forget that the hoses will swell slightly under hydraulic pressure when the brake lever is squeezed. If you double the length of the hose then you double the loss of pressure due to the hoses flexing and it needs double the amount of brake fluid to compensate for that loss of pressure. That means the lever has to travel further to put the same amount of hydraulic pressure on the caliper pistons.
Loz, get a single, good quality, braided hose made up and try that.
Andy.
delpel
Registered user
Nah, I did this with my bike when I ripped out my ABS/SERVO system. Same master cylinder, lines and discs/pads. My lines go done to the lower fork bridge and split to the 2 calipers. I get fantastice initial bite and a good solid feel at the lever.
Regards
Delboy
i'm with tarka on this. the only difference is the extra "give" of the second hose. i reckon there's air trapped in one of the unions or similar. a good power bleed would sort it out i think.
if the equipment is not available, i'd be looking for banjo bolts etc. positioned so that air could rise above the brake lines. some bits might respond well to inversion while bleeding
Gilson
Registered user
Pressure = Force X Area2
I'm with Steptoe. Pressure = Force x Area squared and with two pipes you are spreading the pressure over twice the area. If the master cylinder can only push out 10mls of fluid, with two pipes that's 5 to each side. So in effect you have increased the area by twice (by adding another pipe) and have decreased your braking power by 4 times....
I'm with Steptoe. Pressure = Force x Area squared and with two pipes you are spreading the pressure over twice the area. If the master cylinder can only push out 10mls of fluid, with two pipes that's 5 to each side. So in effect you have increased the area by twice (by adding another pipe) and have decreased your braking power by 4 times....
Number 6
Registered user
No!
The master and slave (ie the piston) cylinder diameters have not changed, so the volume of fluid in the brake pipes is irrelevant.
No!
The master and slave (ie the piston) cylinder diameters have not changed, so the volume of fluid in the brake pipes is irrelevant.
He's right and so's cookie. There must be air in the pipes or one of the pipes has got an anuerism. If the brakes were ok when being worked then air seems the most likely problem.
tinker-27
Guest
brakes
two hoses will not give spongy brakes they would have to be huge and expand to cause this !! get some one to work the brakes on and off look at the gap between the disc and pad if there is a gap even slight you will have to move fliud to take up this space ,some times the anti rattle shim can hold the pad at a slight angle,also take the pads out and make sure they are perfectly flat any bow will cause movement this is why new pads make brakes feel so good (better quality pads tend to be flatter !!),also take of the master cylinder top and very slowly push the pads back into the calipers,any air will vent into the cylinder di this with both calipers(remember slowly!!).when you cleaned the calipers did you take the seals out of the calipers or like most people just the pistons ? corrosion builds up behind the seal making it grip the piston. you can also try loosening the caliper mounting bolts if this inproves the feel then it out of shape pads (dont ride like this!!!) one last thing make sure the lever pivot bolt is free they sieze and the lever does not realease fully,i have just taken servo/abs off my freinds 1150 and they work fantasticly hope this helps,
two hoses will not give spongy brakes they would have to be huge and expand to cause this !! get some one to work the brakes on and off look at the gap between the disc and pad if there is a gap even slight you will have to move fliud to take up this space ,some times the anti rattle shim can hold the pad at a slight angle,also take the pads out and make sure they are perfectly flat any bow will cause movement this is why new pads make brakes feel so good (better quality pads tend to be flatter !!),also take of the master cylinder top and very slowly push the pads back into the calipers,any air will vent into the cylinder di this with both calipers(remember slowly!!).when you cleaned the calipers did you take the seals out of the calipers or like most people just the pistons ? corrosion builds up behind the seal making it grip the piston. you can also try loosening the caliper mounting bolts if this inproves the feel then it out of shape pads (dont ride like this!!!) one last thing make sure the lever pivot bolt is free they sieze and the lever does not realease fully,i have just taken servo/abs off my freinds 1150 and they work fantasticly hope this helps,
Captain Beaky
Registered user
Had exactly the same symptom on my ABS 1150 when I changed the hoses to braided.
Took ages to bleed all the air out.
From experience of the "two hoses from master to wheel calipers" setup on other bikes, they can be harder to bleed (like trying to push water uphill!)
Keep bleeding (use a vacuum bleed kit if you can borrow one).
I found that it made a big difference having someone to pull the lever for me rather than struggling on my own...
M.
Took ages to bleed all the air out.
From experience of the "two hoses from master to wheel calipers" setup on other bikes, they can be harder to bleed (like trying to push water uphill!)
Keep bleeding (use a vacuum bleed kit if you can borrow one).
I found that it made a big difference having someone to pull the lever for me rather than struggling on my own...
M.
Though i'd best let you all know. Loz has fixed it - it was the master cylinder
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