blue95 0 Posted June 11, 2008 Car went for an MOT, it failed :( The front brakes were out of balance - +30% more braking on the passenger side. Front brakes were stripped and cleaned, sliders regreased etc, pads and discs were fine. During the re-test it failed again - this time with 26% difference (You are allowed an inbalance of 25%). When I looked at the machine it looked like less than 25% to me, they guy wouldn't have it though, pretty P'd off TBH What would be the next course of action? pads/discs replaced? Any ideas welcome Quote Share this post Link to post Share on other sites
Supercharged 2 Posted June 11, 2008 As long as the fluid is ok the it will be the caliper - either buy a seal kit or new exchange caliper (no expensive altho I'd buy a pair if both old) Quote Share this post Link to post Share on other sites
boost monkey 0 Posted June 11, 2008 Ditto that. When you stripped the brakes, did you actually take the seals off and clean crud out from around the piston? if it's not moving freely then the brakes could easily be better on one side of the car. We put brand new calipers on Prodigal's G60 last summer and it STILL came up as 11% imbalance! :shock: Quote Share this post Link to post Share on other sites
blue95 0 Posted June 11, 2008 Cheers guys Forgot to mention its the missus's car - 5 year old vectra - told her not to buy vauxhall!!! Might try bleeding it first, as brakes have never been bled. Then look at seals/callipers - I dread to think how much they will cost! Went to the dealership the other week to buy a seal for the exhaust gas recirc valve - they can only do a whole manifold - jokers! Quote Share this post Link to post Share on other sites
Supercharged 2 Posted June 11, 2008 LOL - you know this is the Corrado forum! :) Might try bleeding it first, as brakes have never been bled Are you serious!?! - no wonder it's failed an MOT, probably dangerous to drive too!! Quote Share this post Link to post Share on other sites
blue95 0 Posted June 11, 2008 LOL - you know this is the Corrado forum! :) Might try bleeding it first, as brakes have never been bled Are you serious!?! - no wonder it's failed an MOT, probably dangerous to drive too!! Thats the weird thing, there are no signs when driving. No juddering, no pulling to one side, no funny noises...nothing. Quote Share this post Link to post Share on other sites
dinkus 10 Posted June 11, 2008 Thats the weird thing, there are no signs when driving. No juddering, no pulling to one side, no funny noises...nothing. Yeah, but if there's air in there you'll get a spongey brake pedal... if there's only air in one side then you'll still get a moderately ok feeling brake pedal because the rest of the brakes will be pushing back, but the other one won't be working properly. Quote Share this post Link to post Share on other sites
coolrado 0 Posted June 11, 2008 Brake fluid is hygroscopic, it absorbs moisture, if the fluid hasn't been changed in a long time the chances are it will have quite a high water content, the more water the more spongey and less effective the brakes will be. you can get a little tester that you dip in the resevoir to detect the moisture level, or just completely bleed the system through. Quote Share this post Link to post Share on other sites
boost monkey 0 Posted June 11, 2008 Interesting, I knew fluid was hygroscopic but didn't realise it would absorb moisture unless you left the reservoir open to air. Are the rubber brake hoses porous then? Quote Share this post Link to post Share on other sites
Supercharged 2 Posted June 11, 2008 It's a strange thing, the fluid will absorb water almost by magic, they reckon after a year it's 5% water, after 2 years it can be as high as 12% - I always change mine yearly... Air causes sponeyness and these bubbles are usually caused by incorrect bleeding or the fluid being boiled by hard use or a binding caliper / faulty bearing etc, thats where 5.1 fluid comes in for track days etc as it has a higher boiling point. Quote Share this post Link to post Share on other sites
coolrado 0 Posted June 11, 2008 the brake fluid cap isn't actually air tight though, it has to allow air in as the fluid level drops and allow for expansion if you heat the fluid up too much, the engine bay is also quite a hot and humid place at times, which doesn't help. Quote Share this post Link to post Share on other sites
andy 0 Posted June 12, 2008 Are the rubber brake hoses porous then? Certainly not. If air could get in under atmospheric pressure, hydraulic fluid wouldn't have any issue getting out under hydraulic pressure. To be honest this problem sounds entirely like a seized caliper, I can't believe for a moment its got anything to do with the brake fluid not having been changed. It may be ideal to change fluid more often but how many people really do. I've left fluid in donkeys years longer than that with no ill effects at all. Quote Share this post Link to post Share on other sites
dinkus 10 Posted June 12, 2008 Are the rubber brake hoses porous then? Certainly not. If air could get in under atmospheric pressure, hydraulic fluid wouldn't have any issue getting out under hydraulic pressure. To be honest this problem sounds entirely like a seized caliper, I can't believe for a moment its got anything to do with the brake fluid not having been changed. It may be ideal to change fluid more often but how many people really do. I've left fluid in donkeys years longer than that with no ill effects at all. I'd go with that... or air in the system. Old brake fluid won't be quite as effective, but I can't see how it would cause problems this severe. Supercharged changes his underpants 4 times every day, just in case, so I wouldn't worry too much about some slightly old brake fluid :lol: Quote Share this post Link to post Share on other sites
blue95 0 Posted June 12, 2008 The fluid looks fine (no discoloration) etc, but I will change it anyhow. really struggle to find time to work on any car at the mo, even my Corrado! LOL Quote Share this post Link to post Share on other sites
Go-rado 0 Posted June 12, 2008 It's a strange thing, the fluid will absorb water almost by magic, they reckon after a year it's 5% water, after 2 years it can be as high as 12% - I always change mine yearly... Air causes sponeyness and these bubbles are usually caused by incorrect bleeding or the fluid being boiled by hard use or a binding caliper / faulty bearing etc, thats where 5.1 fluid comes in for track days etc as it has a higher boiling point. Quote Share this post Link to post Share on other sites
Go-rado 0 Posted June 12, 2008 It's a strange thing, the fluid will absorb water almost by magic, they reckon after a year it's 5% water, after 2 years it can be as high as 12% - I always change mine yearly... Air causes sponeyness and these bubbles are usually caused by incorrect bleeding or the fluid being boiled by hard use or a binding caliper / faulty bearing etc, thats where 5.1 fluid comes in for track days etc as it has a higher boiling point. If the fluid absorbs 5% (presumably by volume) of moisture a year, how come the reservoir doesn't start to overflow. I have mne changed every two years but in the meantime, I don't need to top it up and the level stays on maximum. I can't imagine it evaporates at the same rate to compensate. Quote Share this post Link to post Share on other sites
Supercharged 2 Posted June 12, 2008 Yeah good point - the figures I quoted were just what i'd read to be honest and may not be that accurate... As for topping up, should be no need as the level is a good indicator of how worn your pads are... Quote Share this post Link to post Share on other sites
Toad 0 Posted June 12, 2008 Are the rubber brake hoses porous then? Certainly not. If air could get in under atmospheric pressure, hydraulic fluid wouldn't have any issue getting out under hydraulic pressure. To be honest this problem sounds entirely like a seized caliper, I can't believe for a moment its got anything to do with the brake fluid not having been changed. It may be ideal to change fluid more often but how many people really do. I've left fluid in donkeys years longer than that with no ill effects at all. I'd go with that... or air in the system. Old brake fluid won't be quite as effective, but I can't see how it would cause problems this severe. Supercharged changes his underpants 4 times every day, just in case, so I wouldn't worry too much about some slightly old brake fluid :lol: I concur. I heard he was up to 6 pairs, since he puts 2 pairs on at night, and during lunch :scratch: Quote Share this post Link to post Share on other sites
paul20v 0 Posted June 12, 2008 Are the rubber brake hoses porous then? Certainly not. If air could get in under atmospheric pressure, hydraulic fluid wouldn't have any issue getting out under hydraulic pressure. To be honest this problem sounds entirely like a seized caliper, I can't believe for a moment its got anything to do with the brake fluid not having been changed. It may be ideal to change fluid more often but how many people really do. I've left fluid in donkeys years longer than that with no ill effects at all. hoses are porous ,as glass is a liquid , there are many things in life which you would not believe. Quote Share this post Link to post Share on other sites
andy 0 Posted June 13, 2008 hoses are porous ,as glass is a liquid , there are many things in life which you would not believe. Indeed, rhubarb is a herb, tomatoes are fruit. I don't belieeeeeeve it. :shock: Quote Share this post Link to post Share on other sites
blue95 0 Posted June 17, 2008 problem sorted - garage was trying to rip me off :bad-words: Got it checked at a reputabe place and it was well within tolerance :D Quote Share this post Link to post Share on other sites
paul20v 0 Posted June 17, 2008 arseholes , glad you got it sorted fella :thumbleft: Quote Share this post Link to post Share on other sites
