Guest chunkmeister Posted January 30, 2005 Report Posted January 30, 2005 :huh: :huh: hi all,hope someone has answer to my problem ,its a real bi*ch...i have a 1.9 tdi ghia x(2000)galaxy i have changed the front brake pads and all seemed fine.when tested found that pedal had pressure at first then as if overcoming some barrier the pedal travels to the floor,this happens every time the same but onlywhen engine is running????????whhen engine/ignition are off pedal is solid with no give(how it should be)?i am absolutely puzzeledwe did find a bit of fluid by rear n/s bleed nipple and have bled all nipples (front and rear) to be sure but same happening with no fluid loss to show for travel???please help ,....hope there is simple and logical answer to this!thanks (hopefully).chunkmeister :blink: Quote
johnb80 Posted January 30, 2005 Report Posted January 30, 2005 This has come up before and 2 opinions resulted:One said it was okay because the Galaxy is 'over servoed'The other said it's not OK because most other Galaxy's don't do it. My view is that it is a problem and needs sorting. Did you slacken off the bleed nipples to push the pistons back ? Regards - John Quote
Guest dmc Posted January 30, 2005 Report Posted January 30, 2005 did you use genuine ford pads? i have known of some aftermarket pads to cause this. Quote
Ivor_E_Tower Posted January 30, 2005 Report Posted January 30, 2005 After market pads will not cause difference in brake pedal travel. Also, diesels don't have a servo (no inlet manifold vacuum) - they use a brake booster Quote
GSMGuy Posted January 30, 2005 Report Posted January 30, 2005 Ivor is right - unless the pads are actually compressing, it will make no difference - However, diesels still have a servo, exactly the same as petrols - the difference is in the way it is "powered" Whereas a petrol engine is "throttled" and therefore has a plentiful vacuum in the inlet manifold, the diesels are not, so they have to generate the vacuum via a seperate vacuum pump. IMHO, a tiny leak of fluid in the system will cause the symptoms you are experiencing, as when the engine is off, you will have no servo assistance, this makes a BIG difference, to test it, simply turn off the engine and pump the pedal a couple of times to exhaust the vacuum. Then push the pedal as hard as you can, at the same time start the engine - The pedal should go down a good bit further, this is the servo working - if it goes to the floor, you have a leak! To confirm this, release and depress the pedal a good 20-30 times with the motor running,and then go and check the fluid level... HTH Mike Quote
Ivor_E_Tower Posted January 30, 2005 Report Posted January 30, 2005 ..and if the fluid is disappearing, get it fixed ASAP, because you're in big trouble..... Quote
seatkid Posted January 30, 2005 Report Posted January 30, 2005 If it really goes down to the floor and it has been bled correctly (no spongyness with servo exhausted engine off) then... either 1) fluid leak 2) faulty master cyclinder 3) faulty servo If your not losing fluid, most likely faulty master cyclinder. then as if overcoming some barrier sounds like a seal gone in the master cylinder (maybe contaminated with old fluid pushed back during brake change?) Quote
Masked Marauder Posted January 30, 2005 Report Posted January 30, 2005 If it really goes down to the floor and it has been bled correctly (no spongyness with servo exhausted engine off) then... either 1) fluid leak 2) faulty master cyclinder 3) faulty servo If your not losing fluid, most likely faulty master cyclinder. then as if overcoming some barrier sounds like a seal gone in the master cylinder (maybe contaminated with old fluid pushed back during brake change?) I have heard of master cylinder seals being inverted by fluid pushed back up when changing pads, but I don't know if it is a problem on VAG built vehicles. Quote
Guest chunkmeister Posted January 31, 2005 Report Posted January 31, 2005 :huh: thanks guys,looks like its a seas on master,will let you know when it's been done.is this a kit and diy job or professional job? :blink: if diy any details please?thx Quote
Guest chunkmeister Posted January 31, 2005 Report Posted January 31, 2005 :blink: :huh: :huh: i mean seal .lol........ Quote
johnb80 Posted January 31, 2005 Report Posted January 31, 2005 :blink: :huh: :huh: i mean seal .lol........ Hi,Remember you can edit your posts on here, if you make an error again just look at the top R.H. corner of the post and you will see an edit button. Good luck with the brake job. Regards - JB Quote
Guest dmc Posted January 31, 2005 Report Posted January 31, 2005 After market pads will not cause difference in brake pedal travel. Also, diesels don't have a servo (no inlet manifold vacuum) - they use a brake booster as i said,i have personally known of this to happen,some pads can cause a difference in pedal feel.fitting genuine pads cured it. not sure of the reasoning behind it,but can only assume that the pad material was slightly softer,thus compressing very slightly.a small amount of movement of the pad can feel like a large amount of movement at the pedal. Quote
Guest chunkmeister Posted January 31, 2005 Report Posted January 31, 2005 :lol: :lol: :lol: thanks all,it appears travel is a fault in seals for master cylinder.so new one being fitted in am.will post results once my baby is returned.chunk Quote
GSMGuy Posted February 1, 2005 Report Posted February 1, 2005 Question... When you changed the pads, did you use a windback tool and open the bleed nipples, or did you just press the pistons back into the calipers? Mike Quote
johnb80 Posted February 1, 2005 Report Posted February 1, 2005 Question... When you changed the pads, did you use a windback tool and open te bleed nipples, or did you just press the pistons back into the callipers? Mike I asked that question and he pm'd me - He pushed the pistons back without opening the bleed nipples. The lid on the master cylinder was removed whilst this was being done. Regards - JB Quote
Dave-G Posted February 1, 2005 Report Posted February 1, 2005 "The lid on the master cylinder was removed whilst this was being done." :lol: I'd Imagine the resevoir is vented anyway? :lol: Quote
johnb80 Posted February 1, 2005 Report Posted February 1, 2005 Yes it is but only a very tiny hole. Removing the lid does make it much easier to push pistons back and in the event of the reservoir becoming over full it doesn't squirt a jet of paint remover in the air. Quote
Guest ratherhaveanewone Posted February 1, 2005 Report Posted February 1, 2005 Am I to conclude then that it is safe to push the pistons back, without using a bleed hose, if I remove the top from the master cylinder ? Quote
johnb80 Posted February 1, 2005 Report Posted February 1, 2005 Am I to conclude then that it is safe to push the pistons back, without using a bleed hose, if I remove the top from the master cylinder ? I wouldn't risk it myself, any gunge thats collected in the caliper pistons then gets shoved back up the brake lines, better to release the bleed nipple and let the fluid out there. Doing it this way you are steadily renewing your brake fluid :lol: Regards - John Quote
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