rear brake bias valve

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

well after freeing off my rear brake bias valve I have been having more brake probs.

I have never freed my valves off before and wish I hadn't this time either.

Basically pedal is fine for a few applications then the pedal goes to the floor and if you look under at the valve the arm moves back and forth causing a clonking.

I don't understand that myself.

Any ideas?

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

dont worry ...chris h will be along soon..he'll know...

..............oh shit u R chris h!!!

Retroholic Joined: 12 Feb 2004 Posts: 5685

LOL

I had to replace my bias valve for the NCT, once that was done i discovered 2 siezed calipers and the cars nearly spun when i breaked. Cost me a fortune to get it right and it was fine before.

None of which helps...

Forum Moderator Joined: 16 Feb 2004 Posts: 1356

I still think its a seal in the M/S but what do I know!

Retroholic Joined: 12 Feb 2004 Posts: 5685

Do you know where my money is? Smile

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

Well last night after that reply an dbefore I shot over to Georges I replaced the rear caliper.

i tried to bleed it and stuck in a new bleed niplle which tightened up then stripped th ethread. The calipers on the energy were just rebuilt so I stuck that on. Pedals a lot better and th ebrakes are better to.

Will stick the other caliper on and bleed it and the front passenger side. That should be that sorted.

No banging noise from it after I swapped the caliper, but it will probably do it today cos its an arse.

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

Well today I have done the brakes etc.

The rear bias valve still clonks though.

Whats happened is, and this is my educated guess.

The car has been lowered and someone has not adjusted the bias valve.

So when the cars on the ground the spring is free to flop about, this also means the bias valve itself closes slightly.

The small helper spring doesn't pull the arm back enough to fully open the valve up, the spring should be pushing against the arm to stop fully open the valve.

So how to fix, I need to move the sleeve and spring seat along the rod. its threaded etc for this to be possible. But theres the small problem of 12 years of corrosion.

The plastic nut is ok but the metal ones are not.

So the burning question is, are the link rod bits available seperately and if so how much do they be?

Chet, you know I love you, lots, so gimme prices!

Retroholic Joined: 12 Feb 2004 Posts: 5685

You know i'd love to but they're not available seperately, just like every other piece of renault crap

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

well thats just great isn't it.

Maybe I will have to fabricate one or somehow use my enormous brain power to will the rust to drop off and move the nuts and adjust it perfectly without moving my hands.

Retroholic Joined: 12 Feb 2004 Posts: 5685

I'd a safrane one of mine, once again this doesn't help

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

What the hell does that mean?

Does that mean you had a safrane one on yours?

I have the spare bias valve in the shed so maybe I will be able to clean that arm enough to use it.

Retroholic Joined: 12 Feb 2004 Posts: 5685

Yeah thats what i meant, not that it matters lol

Site Subscriber Joined: 05 Apr 2004 Posts: 1141

My rear brake bias valve has ceased, but they still passed it for the MOT - they put the back wheels on rollers and it stopped fine so I left it be.

Does it make a lot of difference?

I might be lowering the valver at some point Neutral

A

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

Well I have sorted mine now as per the progress report.

Anyway the rear bias if siezed in the open position then it will be fine. In the open position the full effort goes to the calipers. If its seized partially closed then the rear brakes won't do much.

Anyway you hear of people saying the car spins etc etc, I dunno how they manage that tbh. Only way that would happen is if the fronts were crap and not doing anything.

i ran the energy with no bias valve so it had full master output, it braked how I like cars to brake.

I reckon a tech artical on how they work and adjustement is in order.

thats the bit you adjust, pull the hook rod out further to increase the rear brake effort.

Retroholic Joined: 12 Feb 2004 Posts: 5685

Man you've gotta love the 3D effect you get from placin stuff on the scanner!

Site Subscriber Joined: 05 Apr 2004 Posts: 1141

Bloody hell you got it off / appart!

Mine wouldn't budge!

If you need any under car pics for your tech report - feel free to rob these I took:

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

oh goodie a new tech article.....im waitin in anticipation...never gone near mine...no need as of yet

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

lol well technically no. I never got it off.

What I did was take the one from the old hatches valve and stripped it so I could swap them over, I de-rusted that one and greased it all up etc then tried to remove the chamades one. No chance, the metal bracket on the axle just started to bend back and forth.

So i had to adjust it on the car.

Thanks for the pics I will use them Addie. Although yours seems cleaner and less rusty than mine!