rear brake failing MOT help!

[titcharoony]

since 08 i have had problems getting my clio through its mot on its rear near side brake. the handbrake always need adjusting, but the braking effort is really poor. so far this time, its had new caliper, pads, master cylinder all replaced, all to no avail. the hoses have been checked and plenty of fluid is coming out. as usual mechanics have ignored my request to not fit any parts without my prior approval, and not replaced the brake hoses.(so replaced a caliper resulting in my third in as many years, instead of the massively cheaper hoses, which have never been replaced, and i DID request a replacement). does anyone have ANY clues as to what this might be? all other brakes are fine. the discs are fine........the mechanics are stumped. any ideas on what to suggest? or try? i also ask if i take to a mechanic who manages to fix this, IF the caliper hasnt been fitted corrected, am i entitled to a partial refund from current garage? help!

[titcharoony]

fitted 'correctly' oh lord i miss the edit button!

[katbloke]

new bias valve, worked for me

[titcharoony]

bias valve? explain please. i know little of cars, less of williams' and even less on brakes. details mon frere!

[katbloke]

have a look under the rear of your car infront of the spare wheel youll see an ally lump with 4 brake lines connected to it and a spring connected to the rear beam. The bias valve adjusts the braking ration front/back depending on the vehicles stance.

The bias valve is also non as a load sensing valve or something like that.

Some times they stick/seize and for 80 give or take from eurocarparts its well worth considering

[titcharoony]

cheers, i cant think of anything else it can be!

[katbloke]

try a read oif this it ight explain it better than i can

http://www.retro-renault.com/forums/...ias-valve.html

[titcharoony]

ahh cheers, just had a quick word with mat brown. said its reasonably common for them for them to seize n might just need freeing up a bit. ill ring em tomorrow n see whats what. thaks for help the article for a real help

[katbloke]

No probs as mat has said its a really common fault, my last valve cam from matt and has sorted mine right out

[northy]

so is it the handbrake effort thats failing or rear brake effort off the foot brake ?

If its handbrake - follow my guide exactly!

(ensure all parts are 100% perfect condition and unsiezed)

loosen & back adjuster right off on the handbrake lever
Take out handbrake cable on adjuster and on the caliper
take out pads
pull caliper lever for the handbrake fully back to - off position
wind in piston
refit pads
Pump the pedal to reseat the rear pads and ensure they are fully home.
refit cables to the caliper and handbrake
Tighten up adjuster and check handbrake - ensure both wheels lock which they will