Brakes unbalanced failed test---

Newbie Joined: 08 Jun 2004 Posts: 15

Hi,
My Renault 19 TSE failed the annual MOT test because the back (drum) brakes are unbalanced. The brakes test report was as follows:
left-side: 1860/1510 N
right-side: 1750/ 800 N
And the hand brake reading was:
Left-side: 1200 N
right-side: 830 N
Eventhough the brake shoes and pistons are quite new, is it possibe that by manually adjusting the brake shoes, that the pistons would then "recover" the correct balance?
OR do you know if there is a mechanism on this model for distributing evenly the brake fluid to the back wheels? I think there isn't, but I'm not fully sure.
Oh ..and does nyone know of a way to check whether the back brakes are corrrectly balanced? I mean without having to have all that expensive equipment. Thank you in advance.

Forum Moderator Joined: 18 Feb 2004 Posts: 7432

Hello welcome to Retro-Renault Peter Smile

cant answer your question unfortunately, but im sure someone will...

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

the drums have seperate feeds fromt he master cylinder.

The shoes are probably not self adjusting, they never do. So get the drum off and adjust them manually. Make sure they stay where yo uset them, if they don't you need to bend the springy plate up a bit.

The wheel cylinders pistons might be seized as they tend to leak and then seize, if they are seized new ones will be needed. They can also go so far then stick again new ones.

have a look adjust them yank on the handbrake if you get a pair of black lines exactly the same length the adjustement is fine.

Newbie Joined: 08 Jun 2004 Posts: 15

Thanks for fast reply. Actually the pistons and shoes are only a year old, and with less than 10,000Kms. So I assume that adjusting the shoes manually will also improve the balance of both the hand brake and the foot brake? I like that idea of yanking on the hand brake and checking the black lines, hadn't thought of that. Thank you

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

yes when the brakes are adjusted properly both the brake and handbrake will be balanced.

Newbie Joined: 08 Jun 2004 Posts: 15

Great, now I just need to find a quiet piece of road (not so easy in Barcelona) to do that handbrake stunt an' measure the black lines. I don't suppose there's any easier of checking for balancing? Thanks, I appreciate the advice.

Mr Quoter-vator Joined: 16 Feb 2004 Posts: 7405

lol i see what the test means now....heh heh good test!

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

try gently pulling up the handbrake to slow the car, it should stay straight. If the car pulls one way or another then its not balanced right.

Newbie Joined: 08 Jun 2004 Posts: 15

Ok...here's the lowdown. I tried pulling the handbrake up gently and it didn't show anything...In fact if anything, the car pulled very slightly to the *wrong* side.
Anyway I got more brave and did the proper test of yanking up the handbrake at about 25 MPH or less, on a very quiet road. And I was able to see the very uneven tracks of the tyres on the road. One thing I found was that it is important to use a nice smooth, and fairly level piece of road (if the surface is rough, you just burn tyre rubber). So I managed to tighten up the brake shoe adjustment on the weaker side. It wasn't even neccessary to remove the shoes. I just passed a wire through a hole in the adjustable shoe, pulling it away from the pistons, and got a small screwdriver at the adjustment, pushing it in at the bottom to tighten it - or you need very strong fingers - very easy. Finally after 2 or 3 adjustments, the tyre marks were very similar on both wheels. I found it was only neccessary to yank up the handbrake for about 1 second, because the important thing is that the brakes *begin* to activate at the same time, you don't need long tyre marks. Well, on Saturday I have to go back for the second inspection...I'll let you know the result. Thank you.

Newbie Joined: 08 Jun 2004 Posts: 15

Well....hmm..failed the inspection once again. So I just got a piece of plastic tube etc and got hold of a passer by to pump the brakes and bled them. Here in Spain they allow a 30% difference of brake pressure in both sides..at least in the back brakes, so in the last test I did it was about 18% so thats that ...for another year...still, would have been nice to get less than 10% difference.

Mr Quoter-vator Joined: 16 Feb 2004 Posts: 7405

well done for sortin it anyway...