Very spongy brakes?

[R1cho]

And the rear cylinders?

they pretty much meet in the middle but have the rubber boot on them to stop them pressing out

 

[solarman216]

rears do not need the pedal pumping they just extend on their own till at the extent of the dust boots, then push them back all the way, all air will end up in the master cyl, do not for get both front and rear are completely separate systems, Rick

 

[makeitfit]

I get it mainly but the load sensor is effectively a higher loop, upturned u bend if you like . So how does the air go up hill and then down again before it can go up to the master cylinder ?

 

[John B]

Where is this valve and will mine have one ???? Cheers

 

[frosty]

Right then progress so far, tried the method Rick suggested and worked to a point, but still a little spongy, so ended up undoing the union of the pipe that goes to the top of the brake sensor got someone to pump the pedal and low and behold it was like undoing a bleed nipple on a house radiator, now they are almost there so am going to see how it goes.

 

[AlexD333]

Right then progress so far, tried the method Rick suggested and worked to a point, but still a little spongy, so ended up undoing the union of the pipe that goes to the top of the brake sensor got someone to pump the pedal and low and behold it was like undoing a bleed nipple on a house radiator, now they are almost there so am going to see how it goes.

Blimey, either say the early bird gets the worm :lol

Keep us posted dude!

 

[makeitfit]

Where is this valve and will mine have one ???? Cheers

Sort of gashed onto the underside of the body just above rear axle. Just a brake valve and a heath Robinson lever and spring stuck on it :lol

 

[rustic]

If working on the brakes, say to replace a rear cylinder, I start off by undoing the reservoir cap, get a plastic bag, screw the cap back on. This seals the system.
Then if you remove a rear cylinder, you don't loose much fluid, if any.

Last time I replaced the brake fluid, I got as much out of the master cylinder as possible, using a turkey baster, then filled with new fluid.

I now use a gunsons bleed system, that has a bottle attached that you fill with fluid, and I managed to get a spare reservoir cap as the ones in the kit didn't fit.
I drilled a hole centrally in this and attached the system, which is then pressurised from a spare wheel, I used a small trailer wheel, at approx 20 psi to feed the system, then just go round each nipple attach a pipe, into a jar and monitor what comes out.

Easy to do on your own, and you get enough pressure and flow to purge any air out.

You need quite a bit of fluid to do a good change.


If in doubt about your ability or state of the braking system, then do not take any risks messing with them.
Replace ALL leaking components, any flexibles showing signs of ageing or fatigue or chaffing, also replace any rusty sections of pipe.

Burnish to bed in new discs or pads or brake shoes.

I use brake cleaner to degrease the discs, pads drums and linings.

Take care not to inhale any brake dust.

 

[frosty]

Well took it for a run yesterday and all seems well so will book it in for the mot, Was talking to a pal of mine who youse to own his own garage a few years ago and when he had problems with the brake compensating valve like my problem he jammed a piece of wood in them to open the valve to make it think there was a heavy load in the car, then he bleeded the brakes and usually got away with it, so if it fails i might try that.

 

[frosty]

Good news it passed it's mot today so hopefully another year with my maverick!!

 

[micktheshed]

If working on the brakes, say to replace a rear cylinder, I start off by undoing the reservoir cap, get a plastic bag, screw the cap back on. This seals the system.
Then if you remove a rear cylinder, you don't loose much fluid, if any.

Last time I replaced the brake fluid, I got as much out of the master cylinder as possible, using a turkey baster, then filled with new fluid.

I now use a gunsons bleed system, that has a bottle attached that you fill with fluid, and I managed to get a spare reservoir cap as the ones in the kit didn't fit.
I drilled a hole centrally in this and attached the system, which is then pressurised from a spare wheel, I used a small trailer wheel, at approx 20 psi to feed the system, then just go round each nipple attach a pipe, into a jar and monitor what comes out.

Easy to do on your own, and you get enough pressure and flow to purge any air out.

You need quite a bit of fluid to do a good change.

That's what I've always done in the past, but the cap on my Terrano cannot be easily made air-tight without modifying, so I'm on the look-out for a spare if anyone can help. I have a 'universal' cap that straps on but it can't be used with the Terrano...typical!
I managed to change the fluid, on my own, without too much cursing but it does take a lot longer. I make a point of using 1L min. of fluid to ensure a good flush-out.
Scrap yards only want to sell a complete master cylinder (understandably) at silly prices. Bearing in mind that it will only get changed every 2 years, it's not worth spending too much.

I have a resistance sensing gauge (for 12 years) that registers water content, & the difference between new fluid & the stuff I remove is always well within the limits. If I didn't use waxoil on the pipes it would be a very different story as this dramatically reduces water absorption.

 

[solarman216]

I get it mainly but the load sensor is effectively a higher loop, upturned u bend if you like . So how does the air go up hill and then down again before it can go up to the master cylinder ?

it is small bore pipe mate the fluid just pushes the air in front of it, no probs, Rick

 

[solarman216]

Where is this valve and will mine have one ???? Cheers

it will be above the rear axle on the drivers side, some have some do not, Rick

 

[frosty]

What is the larger pipe that runs with the rest of pipes, it's about 10mm and has a bleed nipple on the end

 

[solarman216]

What is the larger pipe that runs with the rest of pipes, it's about 10mm and has a bleed nipple on the end

sounds like the clutch so called balance pipe, bin it, it is of no use whatever, Rick

 

[makeitfit]

What is the larger pipe that runs with the rest of pipes, it's about 10mm and has a bleed nipple on the end

Clutch damper pipe :freak3:

 

[frosty]

That's a new on to me never heard of one of them!!

 

[makeitfit]

Nissan seem to think we need one
I binned mine years ago

 

[frosty]

Nissan seem to think we need one
I binned mine years ago

Music to my ears, if I have any problem with the hydraulics on the clutch that's the 1st thing that will come off then.

 

[AlexD333]

Mine had been disconnected.