bleeding issue

[fromos]

hello all me and a few friends have bled my front breaks on a gs850 all bubbles have been removed and it was clear on both sides dual caliper but when it went to testing the front break no compression its pushing the fluid through no problem its just gaining no pressure afterwards any advice would be great caliper seals maybe?

[TC]

Did you use a bleed kit to get rid of the bubbles

[eastanglianbiker]

there is air in the system or the master cylinder is letting by under pressure thats the only things it can be i would go with air in it still,i would blled the front left hand caliper first then the right hand one dont try and do them both at same time as that wont work

[Chrissb6]

Hi, first make sure you are doing the bleed the correct way, either use a none return valve or a bottle with the hose submerged in brake fluid to prevent the air returning into the calliper. If you managed to get the lever hard then move on and try this, pump up the brakes until the lever becomes hard then strap a tie wrap or similar around the lever to keep the pressure on and leave it for a while, on return the lever should remain hard, if not look for external leaks check hoses coupling and the callipers. If there's no sign of a external leaks you can assume that the master cylinder piston-valve is leaking. You might get a service kit from here. Hope this helps

http://www.ebay.co.uk/bhp/suzuki-front-master-cylinder

Edit: l'm assuming its a Suzuki GS850

[buggerit]

silly question but did you tighten up the bleed nipple again??

[fromos]

We used a bottle with the hose submerged in dot 4 we used a aftermarket master cylinder set up on it we put fluid in the top using the left caliper to bleed first we pumped the lever with the bleed nipple open topping up as we went along not letting it drop to far closing the valve once the fluid ran clear we never had a spanner so we had to rachet it which ment remvoing the tube thus maybe pushing air back in ? We repeated the process on the otherside this time maybe ill. Use a spanner meaning I can close it without removeing the tube as I pump the bubbles through should the Lever start to gain pressure?

[Joeman]

we never had a spanner so we had to ratchet it which meant removing the tube thus maybe pushing air back in ?

 

there's your problem!!

Do the nipple up with pressure still on the brake so fluid is still coming out to ensure no air sneaks back in...

[Chrissb6]

we never had a spanner so we had to ratchet it which meant removing the tube thus maybe pushing air back in ?

 

there's your problem!!

Do the nipple up with pressure still on the brake so fluid is still coming out to ensure no air sneaks back in...

That will be your problem, you need to squeeze the lever and nip the bleed nipple up at the same time. Hope your soon sorted

[Joeman]

we never had a spanner so we had to ratchet it which meant removing the tube thus maybe pushing air back in ?

 

there's your problem!!

Do the nipple up with pressure still on the brake so fluid is still coming out to ensure no air sneaks back in...

That will be your problem, you need to squeeze the lever and nip the bleed nipple up at the same time. Hope your soon sorted

 

And if doing it with a ratchet, you will get brake fluid all over the place, so chuck loads of water over or it else it will strip your paint!!!

best to buy a brake bleeding spanner though

[fromos]

Got a spanner now ordered some new copper washers very hard to come by these in Liverpool I noticed yesterday that there was a leak from one of the banjo bolts knowing that copper washers should be changed everytime you change them

[eastanglianbiker]

Got a spanner now ordered some new copper washers very hard to come by these in Liverpool I noticed yesterday that there was a leak from one of the banjo bolts knowing that copper washers should be changed everytime you change them

every time you undo them you mean lol but yep always replace them as once you have crushed them once they dont like it a 2nd time

[Guest]

i always reverse bleed my brakes. especially when changing to fresh fluids..

makes sure there are 1000% no air bubbles in the line...

Also try gently tapping in the brake lever, like, feather it in and out fast..

Some times there can just be a lock of air in the master cylinder...

That fast pulsating action can free it, if there is..

just a couple of tips

[fromos]

Managed to get compression in the end but its still spongey bled the breaks and pumped and released and nipped up still not happening still spongey any ideas ? What about the piston seals there working fine the pistons like

[mattycoops43]

push the pistons in the calipers right back in as far as they go, careful master cylinder doesn't overflow, then pump them back out again with the lever and top up master cylinder as necessary. never failed on any of my bikes, it reverse bleeds but also can move around any lumps of dirt stuck in the calipers.

[Stu]

pump the lever hold and crack the banjo bolt at the master cylinder you may have air stuck in there

[eastanglianbiker]

pump the lever hold and crack the banjo bolt at the master cylinder you may have air stuck in there

or the seals are going weak in the master cylinder

[Ali in Austria]

pump the lever hold and crack the banjo bolt at the master cylinder you may have air stuck in there

 

+1 but make sure you have some thick cloth to catch the spillage. We always included this step after a major overhaul.

[fromos]

Ill try reverse bleeding see if it works out better or not at this point ill try anything

[fromos]

So I tried the zip tye over night method didn't work unfortunately so I'm still left with spongey breaks hmmm I'm lost now really caliper seals or mast cylinder seals I have fully functional braided hoses.

[fromos]

After a closer examination of both calipers one bleed nipple is further out than the other and is actually leeking as you bleed that nipple thus letting in air so new bleed nipple ordered

[Stu]

So I tried the zip tye over night method didn't work unfortunately so I'm still left with spongey breaks hmmm I'm lost now really caliper seals or mast cylinder seals I have fully functional braided hoses.

 

this doesnt work anyway its a myth!!

 

After a closer examination of both calipers one bleed nipple is further out than the other and is actually leeking as you bleed that nipple thus letting in air so new bleed nipple ordered

 

thats not uncommon and probably not the issue

did you try cracking the banjo bolt at the master cylinder like I suggested above?

[fromos]

Yeah tried everything so in goona try the bleed nipple see what happens hope it works like

[fromos]

Something I failed to mention was when bleeding the caliper with the dodgy bleed nipple once I had bled the caliper and closed of the nipple any excess fluid in the tube would then start to make its way back in to the caliper even though the nipple was closed so I'm sumising that was the problem

[eastanglianbiker]

was the fluid making its way back into the caliper or just back up the hose and running out round the nipple,but fit new ones see what happens

[fromos]

the orignal one was i fitted the new bleeder today it goes in as far as the other one on the otherside all was running clear again but still seepage from the threaded area is there some kind of sealent that i could use that would work ? thats where my problem lies im pretty sure of it gasket sealer or something?