inky 0 Posted January 11, 2008 HI, little bit of advice please, last couple of days brakes have become very spongy...they are still there but pedal travel is a long way down to get brakes. Have checked servo and that is fine, have not had any brake work done recently and pads and discs are always done at the same time. And have no leaks anywhere Could it probably be the master cylinder ? any advice would be greatly appreciated...(afterall i am a female!!) :( Quote Share this post Link to post Share on other sites
pete_griff 0 Posted January 13, 2008 if the reservoir above the master cylinder (by the servo) is full, then the only things it could be are: master cylinder any one of the slaves on the actual calipers themselves - maybe a seal gone any of the flexible hoses (6 on a corrado) how many miles has the car done - wouldn't like to say which of those is the most likely in all honesty - but you should check them all at the earliest opportunity look for residual leakage around the calipers, hoses and master cylinder... the only other thing that is far less likely is that one of the connections in the solid lines or one of the bleed nipples has somehow started working itself loose and you've some how got air in the system... on that note, was the reservoir really low when you last topped it up?.... i don't know enough about the internals of the abs pump to comment, but i guess it's also possible that a seal in there could have gone as well (which is probably the worst case scenario) - you'd have to ask someone more knowledgable than i veeeeeeeeeeeeeerrry strange anyway - good luck with that one Quote Share this post Link to post Share on other sites
inky 0 Posted January 13, 2008 hi....thanks for you reply, I was only joking when I said 'im just a woman' I am quite knowledgeable with cars, having had this one for 3 years now anyway thanks but itis now sorted, process of elimination and new master cylinder and voila BRAKES again :D Quote Share this post Link to post Share on other sites
dr_mat 0 Posted January 13, 2008 You're sure it wasn't just an excess of *water* on the brakes ... ?! Quote Share this post Link to post Share on other sites
pete_griff 0 Posted January 14, 2008 HI, little bit of advice please, last couple of days brakes have become very spongy...they are still there but pedal travel is a long way down to get brakes. Have checked servo and that is fine, have not had any brake work done recently and pads and discs are always done at the same time. And have no leaks anywhere Could it probably be the master cylinder ? any advice would be greatly appreciated...(afterall i am a female!!) :( You're sure it wasn't just an excess of *water* on the brakes ... ?! good call - but water on the brakes wouldn't affect pedal travel, even if it would take more pressure to make them work as normal.... Quote Share this post Link to post Share on other sites
inky 0 Posted January 14, 2008 actually los tthe brakes again today so back to garage and find out few weeks ago had a binding brake at back so have been boiling the fluid, hence air so now looking at new calipers :( Quote Share this post Link to post Share on other sites
pete_griff 0 Posted January 14, 2008 thats unlucky - don't know how old your fluid is, but if it's boiling from the rear calipers alone (even if they are seized) then you could have too high a water content in the fluid; lowering the boiling point. guess you've having all new fluid when you get new/recon calipers anyway... Quote Share this post Link to post Share on other sites
vwdeviant 0 Posted January 14, 2008 Or try silicon "race" fluid which has a higher boiling point.. but beware it doesn't mix with regular fluid so whole system will need draining and refilling.. Quote Share this post Link to post Share on other sites
Supercharged 2 Posted January 14, 2008 Or try silicon "race" fluid which has a higher boiling point.. but beware it doesn't mix with regular fluid so whole system will need draining and refilling.. You can't use silicon based fluids at all with VW's - particuarly the ABS system I believe... Halfords Dot 5.1 is the stuff to use - £3 a ltr with a trade card! Inky - as above, spongy brakes usually means air in the system - when was the fluid last changed? Quote Share this post Link to post Share on other sites
inky 0 Posted January 14, 2008 RIGHT....I dont have ABS had the master cylinder changed for brnad new one on sat morning, system flushed and refilled felt fine on sat afternoon and sunday sunday night hubby borrows (he always breaks it) and takes to work, comes hone this morning and didnt mention brakes I go out and as soon as start off they feel spongy again!! :( rang garage and took it back they had a good look and said that because the back brake had been binding recently, that maybe as he had driven it a fair few miles thatit was poss that the fluid was boiling and causiing air pocket they flushed the system again and there was air from that wheel (although not binding anymore), so said that poss now will need new caliper brakes are now fine again, but if i drive it too far will prob have no brakes again (and we are supposed to be going away for a few days at the weekend in the raddo :( ) So am now having to get new calipers Quote Share this post Link to post Share on other sites
pete_griff 0 Posted January 14, 2008 Or try silicon "race" fluid which has a higher boiling point.. but beware it doesn't mix with regular fluid so whole system will need draining and refilling.. You can't use silicon based fluids at all with VW's - particuarly the ABS system I believe... Halfords Dot 5.1 is the stuff to use - £3 a ltr with a trade card! Inky - as above, spongy brakes usually means air in the system - when was the fluid last changed? how come you can't use silicone fluid - i'm using it with my my new calipers and i have abs and it's been working very well... do you know something i don't?! :? also the silicone stuff will mix with normal fluid as far as i'm aware (i know for a fact my automec stuff will as it says so on the destructions) - only thing is that you don't want it to mix as the normal stuff will affect the performance Quote Share this post Link to post Share on other sites
pete_griff 0 Posted January 14, 2008 RIGHT....I dont have ABS had the master cylinder changed for brnad new one on sat morning, system flushed and refilled felt fine on sat afternoon and sunday sunday night hubby borrows (he always breaks it) and takes to work, comes hone this morning and didnt mention brakes I go out and as soon as start off they feel spongy again!! :( rang garage and took it back they had a good look and said that because the back brake had been binding recently, that maybe as he had driven it a fair few miles thatit was poss that the fluid was boiling and causiing air pocket they flushed the system again and there was air from that wheel (although not binding anymore), so said that poss now will need new caliper brakes are now fine again, but if i drive it too far will prob have no brakes again (and we are supposed to be going away for a few days at the weekend in the raddo :( ) So am now having to get new calipers before you go sheeling out on new calipers - you could just try giving yours a good clean, in particular the sliders on the carriers that the pads sit on - they often get rusty and full of crap. cleam 'em up and give the sliding area and the back of the pads a good dose of copper grease and see how you get on... Quote Share this post Link to post Share on other sites
skinnyman9000 0 Posted January 16, 2008 I had a binding rear caliper, i replaced that and then when i went for a drive i had the excess travel problem too, which wasnt there before. It feels like the initial 1" of the brake pedal does nothing, then the brakes begin to work. Ive spent a fortune on the braking system over the past year, but after doing some research i found that when the entire braking system is bled it puts excessive strain on the master cylinder, and if its an old one it can cause them to fail. I haven't gotten around to changing mine yet, but it sounds like a very similar thing. They're around £50 from GSF i believe, so when payday kicks in i'll be giving it a go. Or i might just take it to Midland VW to have a look at, as i have a throttle issue too, plus i HATE flushing/bleeding the brake system, ive done it faaaar too many times now, on various cars, already done it twice on the rado Quote Share this post Link to post Share on other sites
dr_mat 0 Posted January 16, 2008 I had a binding rear caliper, i replaced that and then when i went for a drive i had the excess travel problem too, which wasnt there before. It feels like the initial 1" of the brake pedal does nothing, then the brakes begin to work. Pull the handbrake up half a click (without engaging it) .. the brakes feel fab don't they? I have to say I'm not sure I'd trust my braking system to a GSF part. Fine if you're flogging the car in 6 months, but if it's a long term prospect pay the VW tax. Quote Share this post Link to post Share on other sites
inky 0 Posted January 16, 2008 have already forked out for new master cylinder and now find it maybe wasnt that at all :( hubby is taking to work tomorrow again so will see if brakes are there when he comes home if not then def prob with boiling fluid and will have to sortout rear calipers Quote Share this post Link to post Share on other sites
