Foss Posted March 17, 2021 Posted March 17, 2021 Installed new rear brake caliper on bike, have been trying to bleed now for 2 days, no joy, Looking at the master cylinder have noticed 3 outlet pipes, one to reservoir, one to calliper, and another to engine, what does the one to engine do ? and is it affecting my bleeding process ? Thanks All Quote
Stu Posted March 17, 2021 Posted March 17, 2021 Hi and welcome to the forum What bike is it? it may have linked brakes Quote
Foss Posted March 17, 2021 Author Posted March 17, 2021 Hi Sty, its a Chinese AJS Scrambler, 125 Quote
Foss Posted March 17, 2021 Author Posted March 17, 2021 If it does have linked brakes, what is the correct bleeding procedure ?Thanks Stu ! Quote
husoi Posted March 17, 2021 Posted March 17, 2021 Main rule in the forum! No photo, it doesn't exist... Linked brakes (as seen on Honda CBS) is a real pain. You will need to bleed all callipers, front and rear, several times. Make sure you keep an eye on fluid levels, last thing you want is to have air getting into the lines. You will have 2 reservoirs that must be kept at level at all times. Quote
fastbob Posted March 17, 2021 Posted March 17, 2021 It almost certainly does have linked brakes . I've no idea what the procedure is without getting hands on . Which lever are you pressing to bleed the rear calliper ? Quote
Foss Posted March 17, 2021 Author Posted March 17, 2021 Pumping rear brake pedal, with no effect. no resistance whatsoever ! Quote
Foss Posted March 17, 2021 Author Posted March 17, 2021 8 minutes ago, husoi said: Main rule in the forum! No photo, it doesn't exist... Linked brakes (as seen on Honda CBS) is a real pain. You will need to bleed all callipers, front and rear, several times. Make sure you keep an eye on fluid levels, last thing you want is to have air getting into the lines. You will have 2 reservoirs that must be kept at level at all times. Thank you, will go and have another look, however front brake does work fine ! Quote
husoi Posted March 17, 2021 Posted March 17, 2021 2 minutes ago, Foss said: Thank you, will go and have another look, however front brake does work fine ! It doesn't matter if the front works fine, because is a linked system air would have entered the linking line. The rear reservoir is quite small so you want to make sure it doesn't run out. I had a similar problem with my VFR800 and spent hours trying to bleed it. only when I left it alone for a couple days the system self-purge and all air disappeared. How I did it I don't have a clue Quote
Foss Posted March 17, 2021 Author Posted March 17, 2021 5 minutes ago, husoi said: It doesn't matter if the front works fine, because is a linked system air would have entered the linking line. The rear reservoir is quite small so you want to make sure it doesn't run out. I had a similar problem with my VFR800 and spent hours trying to bleed it. only when I left it alone for a couple days the system self-purge and all air disappeared. How I did it I don't have a clue Thanks Husoi ! Quote
Foss Posted March 17, 2021 Author Posted March 17, 2021 Just now, Foss said: Thanks Husoi ! I assume i would bleed front brake the conventional way using nipple? Quote
husoi Posted March 17, 2021 Posted March 17, 2021 5 minutes ago, Foss said: I assume i would bleed front brake the conventional way using nipple? NP, I've made my own bleeding valve but you can get one for around £12 online. It helps in linked systems . 1 Quote
Foss Posted March 17, 2021 Author Posted March 17, 2021 32 minutes ago, husoi said: NP, I've made my own bleeding valve but you can get one for around £12 online. It helps in linked systems . Got a pump, just done front brakes no problem, back still no joy ! Quote
Foss Posted March 17, 2021 Author Posted March 17, 2021 Just now, Foss said: Got a pump, just done front brakes no problem, back still no joy ! I assume l will have to disconnect the linked pipe from master cylinder ??? Quote
Foss Posted March 17, 2021 Author Posted March 17, 2021 4 minutes ago, Foss said: Got a pump, just done front brakes no problem, back still no joy ! Quote
husoi Posted March 17, 2021 Posted March 17, 2021 4 minutes ago, Foss said: I assume l will have to disconnect the linked pipe from master cylinder ??? No, the bleeding valve is connected to the bleeding nipple just prevents air to get back in when you release the lever/pedal Quote
Foss Posted March 17, 2021 Author Posted March 17, 2021 1 minute ago, husoi said: No, the bleeding valve is connected to the bleeding nipple just prevents air to get back in when you release the lever/pedal Yes, Have been doing that for days, still no resistance !! Quote
Foss Posted March 17, 2021 Author Posted March 17, 2021 Just now, Foss said: Yes, Have been doing that for days, still no resistance !! Its pulling fluid through?? Quote
husoi Posted March 17, 2021 Posted March 17, 2021 how's the level in the rear reservoir? Without pressure in the system if you open the rear bleeding nipple you should get a slow run of brake fluid. Quote
husoi Posted March 17, 2021 Posted March 17, 2021 11 minutes ago, Foss said: Got a pump, just done front brakes no problem, back still no joy ! When you say you got a pump, what kind of pump is it? Vacuum pump that you plug to the nipple and pulls the fluid out? Quote
Foss Posted March 17, 2021 Author Posted March 17, 2021 1 minute ago, husoi said: how's the level in the rear reservoir? Without pressure in the system if you open the rear bleeding nipple you should get a slow run of brake fluid. Keep filling rear res, and pulling it through bleed nipple, not making any difference ! Quote
Foss Posted March 17, 2021 Author Posted March 17, 2021 Just now, Foss said: Keep filling rear res, and pulling it through bleed nipple, not making any difference ! Just done the front, No problems, working fine ! Quote
husoi Posted March 17, 2021 Posted March 17, 2021 I assume you have already check this: pads are near the disk with a little gap. There are no leaks in rear line. Lack of pressure would mean that there is a leak or the pistons are not yet in place but as the system fill up you would start to get some pressure. Does the master cylinder works properly? Quote
Foss Posted March 17, 2021 Author Posted March 17, 2021 1 hour ago, husoi said: I assume you have already check this: pads are near the disk with a little gap. There are no leaks in rear line. Lack of pressure would mean that there is a leak or the pistons are not yet in place but as the system fill up you would start to get some pressure. Does the master cylinder works properly? Starting to think the Master cylinder has had it, No leaks in line i can see, do pads have to be in a certain position ? Quote
Foss Posted March 17, 2021 Author Posted March 17, 2021 7 minutes ago, Foss said: Starting to think the Master cylinder has had it, No leaks in line i can see, do pads have to be in a certain position ? Its a new caliper, so piston is pushed right in ! Quote
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