pulsar brakes

[jim_bling]

i have these on my car had them on for a while bled them so there was no air in the cables or anything but they still feel really spoungy. I expected the brakes to be quite affective, as if i was to tap the brakes, i would feel the car stoping but i dont my foot has to be pressed a fair bit for there to be any pressure on the disks. I put new pads and disks on and still feels the same yet the hand brakes is spot on works better than the front ones what could be up with them ?????

 

[frank]

kenny

if they,re spongy, there must still be air in the system, have you bled all 4 corners

 

[jim_bling]

i only need to do the front ones as that was the only ones i changed surley and the back brakes when i put the hand brake on is spot on

when you press the pedal does it engage just the front brakes or the rear ones as well

 

[whipit]

i have these on my car had them on for a while bled them so there was no air in the cables or anything but they still feel really spoungy. I expected the brakes to be quite affective, as if i was to tap the brakes, i would feel the car stoping but i dont my foot has to be pressed a fair bit for there to be any pressure on the disks. I put new pads and disks on and still feels the same yet the hand brakes is spot on works better than the front ones what could be up with them ?????

Handbrake runs off of a cable as a opposed hydraulic. Sounds like the whole system needs bleeding, are the calipers the right way round, brake nipple at the top?

 

[Craig]

What state are the disks+ pads in - are you sure that the calipers are even moving?

Craig

 

[jim_bling]

calipers are the right way around and they do work but only when you press down hard on the pedal if i was to press down about 25% i cant feel anything but when i press down about 60 % i can finaly feel the pads touching the disk but if im rapidly breaking from 70 to a stand still at a round about and i press 100% they work great

the pads and disks are new craig

 

[whipit]

Well have to remember they do need a lot more fluid.

 

[frank]

kenny

you can usually tell which corner has air in by clamping each flexi hose in turn and feeling the brake.
and most car brakes are split diagonally ie, o/s/f and n/s/r are linked etc

 

[NeX]

i only need to do the front ones as that was the only ones i changed surley and the back brakes when i put the hand brake on is spot on

when you press the pedal does it engage just the front brakes or the rear ones as well

because your car is not a rally car, the braking system is all in one. (rally cars have one piston for the fronts and one for the rears,)

the micra has a single master cyilinder, this is connected to the brake pedel, when you push this it forces fluid into both the front brakes and the back. there is a bias at the back that changes the ratio depending on how much load there is in the back of the car. you want the front brakes engaging first and then the rears, as the weight shifts to the front when you brake. the brake system is crossed so that the front right caliper works with the rear left and vice versa, this is so if you have a fail in one of the pipes the car still brakes in a straight line because both sides still have a working brake.

if you have compramised the system (taken a caliper off) then the entire system will need to be bled, both front and rears. this is a pain in the arse and i get garages to do it just because its so hard on your own and such a critical part of the car.

the hand brake opperates the back brakes only and uses a cable, this is because it gives you and extra backup in case the hydrolic system fails.

 

[jim_bling]

frank you have lost me there

whipit are you saying that this is normal

shall i just blead all the brakes and surely there is a way to allow enough fluid through the servo bit to tighten up the pedel response

ah right cheers nex will get it sorted the tomorrow morning after work will blead all 4 brakes see if that makes much differance if not how do i make it so there is more pressure on the front than the back

also nex do you have msn

 

[whipit]

I'm saying i have no idea how it feels but its normal to feel some difference. Bleed the system completely first.
And Nex isn't the bias valve at the front and doesn't adjust?

 

[NeX]

frank you have lost me there

whipit are you saying that this is normal

shall i just blead all the brakes and surely there is a way to allow enough fluid through the servo bit to tighten up the pedel response

ah right cheers nex will get it sorted the tomorrow morning after work will blead all 4 brakes see if that makes much differance if not how do i make it so there is more pressure on the front than the back

also nex do you have msn

frank is mentioning what i did, that the brakes are linked diagonally accross the car. by putting a clamp like some mole grips on the pipes that go to the caliper and then testing the pedal for spoungyness, you can find out which caliper has the air lock in it.

you can't put more fluid in to tighten it up, the problem is that when you push the pedal all you are doing is squashing the air bubble, not pushing the brake pads. the bubble wont move until you drain it from the system.

the brake bias is done automatically. look under the car at the back you see a box thing that looks like a mini abs unit, its attached by a spring to the rear beam. as the back of the car goes down (more weight in the back) the bias is automatically adjusted. so you don't need to worry about that, the front brakes are stronger anyway, its just to make sure that the back wheels don't lock before the fronts or you will lose control like jamming the handbrake on whilst driving.

msn is: NeX_is (at) hotmail (dot) co (dot) uk

I'm saying i have no idea how it feels but its normal to feel some difference. Bleed the system completely first.
And Nex isn't the bias valve at the front and doesn't adjust?

pretty sure it is at the back, if not i don't know where else it would be. i might be wrong, but i know 100% that there is a thing at the back which all the brake pipes go into and its attached to the suspention,

anyone else confirm this is the bias or something else?

 

[frank]

nex

yeh, the load apportioning valve (bias valve) is linked to the back axle, and is adjustable

 

[ollie240585]

nex

yeh, the load apportioning valve (bias valve) is linked to the back axle, and is adjustable

Located on the passenger side of the car, above the rear axle near the spring if i remember correctly.

It looks like a small shock absorber with metal pipes running in and out of it.

 

[jowley]

you may need the master cylinder and servo off the gti

 

[NeX]

you may need the master cylinder and servo off the gti

na, it makes no difference, the force you apply at the brake pedel end is multiplied by the hydrolic system at the caliper, so there is no need to change anything.

if you wanted more force acting on the brakes then you would have to find a smaller master cylinder, but that would just mean that the brakes are really sensitive and because the micra doesn't have ABS it would lock up really easy

 

[whipit]

nex

yeh, the load apportioning valve (bias valve) is linked to the back axle, and is adjustable

had a k10 for too long!