Failed MOT for rear brake imbalance

[ourboy]

I need help..
I booked my 172 cup in for mot at the start of the month which it failed.
the guy said it was an imbalance with the foot brake on the rear brakes.
so that weekend I looked at them to see what was happening.
The disks looked as if they where on there way out to went to renault and got nice new disks and pads.I also replaced the brake fluid and tryed to free up the caliper piston and it seemed to wind in and out freely so i rebooked my car for a few days later

Failed again for the same thing

so I thought the drivers rear caliper must be f**ked

replaced and reblead brakes and rebooked

Failed again for the same thing

I'm starting to run out of idea's

I know about the 172 cups having low braking effort but they said they are out of ballance

I have only owned this car for 3 months and love it but this is starting to f**k me right off

what do you think?

 

[James.f]

theres an article about the rear brakes on the Cup, all you have to do is show it to them and they will pass it,

il have a look for it now..

http://www.dft.gov.uk/vosa/repository/MoT Issue 31 - Apr 2006.pdf

 

[Gumby]

http://www.dft.gov.uk/vosa/repository/MoT%20Issue%2031%20-%20Apr%202006.pdf

Have a read (last page)

 

[SBV116]

^ what he said! You can still turn the wheels when your foot is fully pressed!

 

[ourboy]

 

[ourboy]

I have showed them 3 times now and i got 3 different guys????

 

[SBV116]

So the O/S rear is reading low, if the pads and discs are ok as you say. try another caliper!

Edit, I can't remember, been a while since i did mot's personally, but i am sure you can't fail imbalance on the rear. Do not quote me though.

 

[ourboy]

so your saying this applys to an imbalance as well as low braking effort?

 

[ourboy]

So the O/S rear is reading low, if the pads and discs are ok as you say. try another caliper!

.

yea o/s rear is lower and new caliper on still made no difference

 

[Tom84]

as far as im aware you cannot fail a car for rear brake imbalance you can only do this on the front. now im tester and im possitive you cannot fail it on that. i would ring up vosa, im sure the number is on the back of the mot and ask them to comfirm this

if the tester is still being picky, ask for him to do a decelerometer test and it will pass no problem

edit.

quick search for this

''Rear imbalance (or more pedantically, imbalance on non-steered axles) is not a reason for rejection, so, providing each side meets the minimum brake force requirements when tested, it will pass. On steered axles, 25% imbalance is allowed''

 

[ourboy]

does no one else get a print out with the braking values on it or is it only mot centres in n.ireland?

 

[ourboy]

as far as im aware you cannot fail a car for rear brake imbalance you can only do this on the front. now im tester and im possitive you cannot fail it on that. i would ring up vosa, im sure the number is on the back of the mot and ask them to comfirm this

if the tester is still being picky, ask for him to do a decelerometer test and it will pass no problem

edit.

quick search for this

''Rear imbalance (or more pedantically, imbalance on non-steered axles) is not a reason for rejection, so, providing each side meets the minimum brake force requirements when tested, it will pass. On steered axles, 25% imbalance is allowed''

where did you get this information if you don't mind me asking as I would love to have the upper hand

 

[Tom84]

forget me just seen ur in NI and they have different rules

quote

''The out-of-balance of the Service brakes on ANY AXLE, greater than 30%''

 

[ourboy]

here is the display read out

 

[foxspeed]

rear brakes - perhaps its not the low effort one thats at fault - its a cup so should have "low" effort on both sides - perhaps the issue is the side with the high reading ?

 

[ourboy]

never thought of it like that
has anyone any results for the braking effort on the rear so I could compare?

 

[ourboy]

I don't know where to go from here.

I cheched the n/s caliper when I was checking the o/s and it seemed fine:S

 

[ourboy]

is it possible that a caliper could be working to well?

there are so many questions in my head right now

lol

 

[ourboy]

or is it possible that I have a mismatched caliper on the side that is reading high braking effort?- from the factory..

I bought the car in england about 3 months ago and because an imbalance in the rear wheels does not fail the car in england this fault would never of been spotted before.

 

[ourboy]

I have removed the brake compansater under the rear axle to have a look.

and it is completely F***ed
inside I found two valves (one for the L/H rear & R/H rear wheel)
the one controling the R/H rear was seized and caked in rust and dirt so got on the phone to renault and ordered a nice new ..

 

[ourboy]

It looked like the sized valve had been redirecting the pressure from the R/H rear to the L/H front

 

[ourboy]

 

[ourboy]

I still have book the car in for an other retest to confirm all this but looking at the state the valve was in I think we may have got it sorted

 

[ourboy]

 

[W111ALG]

Can I ask how much the brake compensator was from Renault?

Cheers

Will

 

[ourboy]

£117

 

[W111ALG]

Cheers for that - hope it fixes your issues!

 

[ourboy]

not tested on rollers yet but I can tell already that they are s**t hot

 

[ourboy]

Cheers for that - hope it fixes your issues!

Thanks

 

[BRUN]

good luck mate, hate issues like this

 

[ourboy]

Every days a school day lol

 

[ourboy]

just to let you know she passed tonight .

 

[ourboy]

 

[foxspeed]

just to let you know she passed tonight .

excellent :approve: