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MOT Failed
Posted: Tue Sep 14, 2010 12:43 pm
by mattyf
Just had my car in for it’s MOT and it’s failed on a few bits

one I really don’t understand??!!
The fail sheet says that there’s a 27% Front Brake Imbalance, what’s this??

Mechanic said it’s probably the front brake pads?!
Any help would be appreciated.
Many thanks
Matt
Re: MOT Failed
Posted: Tue Sep 14, 2010 12:52 pm
by gumby6371
Matty, the imbalance just means one side is braking harder than the other, could well be in need of new pads.
My advice would be find a garage offering free brake checks and see what they say, if it's a nice easy job like changing the pads, smile, thank them very much, go home and fit them yourself

Re: MOT Failed
Posted: Tue Sep 14, 2010 12:56 pm
by highlander
Suggests that the brakes on the front axle don't brake evenly (i.e. one brakes 27% more effectively than the other), which means that as you apply the brakes, your car should drift to one side.
Easy to see why that's an MOT fail - imagine having to stomp on the brakes and then finding yourself either on the pavement (potentially mowing down pedestrians) or on the other side of the road (potentially plowing into oncoming traffic)
As the MOT Inspector has said, it's likely to be the front brake pads, but could be a number of other things related to the brakes too (warped discs, calipers, etc). If you're not sure or (like me) you want someone to do it for you, get it in to a reputable local garage (i.e. not Kwik-Fit) and get them to check your brakes over for you.
Brakes are one thing I won't touch myself; they're far too important a function for me to screw up
EDIT: Ninja-post by gumby6371 - but I've typed my post, dammit, so I'm posting it

Re: MOT Failed
Posted: Tue Sep 14, 2010 1:21 pm
by mattyf
Cool thanks .. yeah I don't really like messing with brakes either

, but I live 20mile journey from work with little money so I might just have to try. I've fitted brake pads before as they don't need you to bleed the system.
Well I think I might take a company up on there "free brake test" as suggested.

Re: MOT Failed
Posted: Tue Sep 14, 2010 1:32 pm
by teamster1975
It's not a difficult job to bleed the brakes if needs be, just make sure you buy a descent brake spanner for the bleed nipples!
As the other guys say check the pad wear on either side. Before you squeeze the pistons back in check for and clean off any crud around the piston base as this will damage the seals. Definitely a DIY job, just get yourself a halfords brake bleeding kit. It's basically a clear tube with a one way valve, costs a fiver.
Re: MOT Failed
Posted: Tue Sep 14, 2010 1:57 pm
by mattyf
That sounds like a plan!! I like to learn how to do things .. makes garage costs drop ever so slightly when you can fix it your self!

Re: MOT Failed
Posted: Tue Sep 14, 2010 7:00 pm
by swiss
Word of warning, I swapped out the front discs and all four pairs of pads on the Omega and it still only just scraped through on the limit of brake imbalance >.<
Re: MOT Failed
Posted: Tue Sep 14, 2010 8:05 pm
by jasper5
The imbalance thing is a pain sometimes, you can have everything perfect (as swiss says) and the imbalance is only just inside the limits, but take the car up the road, brake hard a few times and you will get different figures, also if the tester runs the brake rollers and stamps on the pedal a few times you will get a different reading (my mate Steve has done this for me a few times.)
If the brakes haven't been done then you need to check if the pads are rusted into their slots in the calipers, also check the slider pins for being siezed, fit a new set of pads and give them a good bedding in session.
I replaced the discs and pads on my Expert van this afternoon, the pads were siezed solid in their slots, despite me freeing them off only 6 months ago.
Yes, I know people say use copper grease, but I hate using that stuff, it gets everywhere, including on discs and pads.
Re: MOT Failed
Posted: Tue Sep 14, 2010 9:37 pm
by steve_earwig
I hate using it too but the alternative is seized components, as you had. Use sparingly, smear it on the insides of the calipers where the pads go, carefully put the pads in and a smear on the pins for good measure.
Re: MOT Failed
Posted: Thu Sep 16, 2010 5:37 pm
by briangriffin
It's probably different, but I had a Peugeot Partner that failed for the same reason. The garage cleaned and greased the Front pads and gave me a ticket. One week later the brakes started to stick on so I repeated the excercise. Three days later with the fronts sticking on I fitted new pads. There then came a period where the brakes stuck on after 10 miles, they stuck so badly that the car would almost come to a stand still. Taking the advice of a local Peugeot specialist, I changed the front flexy. This made no difference and so I bought a new caliper and fitted that. Once more this had no effect and so as there was nothing left to try, I had a new Brake master cylinder fitted. At last the problem was sorted, but remember the Peugeot Partner was a very simple car, 406's are not.......
Re: MOT Failed
Posted: Thu Sep 16, 2010 6:04 pm
by jasper5
steve_earwig wrote:I hate using it too but the alternative is seized components, as you had. Use sparingly, smear it on the insides of the calipers where the pads go, carefully put the pads in and a smear on the pins for good measure.
To be honest, I only freed them off 6 months ago as a temporary thing because they were whistling, unfortunately, I never got round to changing the discs and pads sooner, as I should have done, usually I use high melting point grease on the pads and pins, as I have done this time with the new pads.
Re: MOT Failed
Posted: Thu Sep 16, 2010 6:31 pm
by steve_earwig
Fairy nuff, I didn't want to leave it at that though as people will read your post and think "Jasper doesn't bother so why should I?"
My favourite is drum brake shoes, nice dob of copperslip on all the relevant points, put together and... a half hour battle later it's everywhere
@ Mssr. Griffin: st5icking valve in the m/cylinder, sounds like it led you a merry dance

Re: MOT Failed
Posted: Sat Sep 18, 2010 7:34 pm
by briangriffin
steve_earwig wrote:Fairy nuff, I didn't want to leave it at that though as people will read your post and think "Jasper doesn't bother so why should I?"
My favourite is drum brake shoes, nice dob of copperslip on all the relevant points, put together and... a half hour battle later it's everywhere
@ Mssr. Griffin: st5icking valve in the m/cylinder, sounds like it led you a merry dance

Certainly did. I can remember coming home with the Peugeot and it's new MOT and uttering the imortal words " great, now I won't have to spend anything else this year!" famous last words. Still I got the last laugh, swopped the Partner in for a 406 , I think they call it out of the frying pan into the fire.
