Soft brakes

[Steve]

I upgraded to UK brakes all round around 5 years ago and they have been fine up until now.]

Basically the pedal feels to have gone soft and i can easily push the pedal to the bottom of its travel when driving. I have bled and bled the brakes but there is no air in there at all.

 

I have noticed though between where the brake servo is and where the master clylinder bolts to it the paint on the servo is flaking away as if it has been leaking.

 

Would it just be a seal between the cylinder and the servo that is leaking causing this soft feel?

 

The pedal does go hard with the engine off when pumped to i guess the servo is ok?

 

I am also going to fit a brake stopper to stop some of the flex in the servo/cylinder but would rather fix this first.

 

Any input would be great

[David P]

Sounds like you could need new seals in the brake master cylinder.

 

Are you loosing any brake fluid?

[Graham S]

With the engine turned off, pump the pedal till its hard, hold it down then start the engine. It should sink to normal height, which says your servo is working.. But does sound like it got a leak somewhere. As David said, are you loosing brake fluid?

[kjgreen3]

If you can rule out that it's not the seals then have you pressure bled the system? Because its a right PITA to get the air out of the ABS system. I bled mine 4 times and the pedal was still soft. Bought a Gunson Pressure bleed kit and with the use of a G -clamp pressure bled the system once and cured the spongyness immediately.

[Steve]

Sounds like you could need new seals in the brake master cylinder.

 

Are you loosing any brake fluid?

 

There are no signs if fluid leaking anywhere other than the flaking paint on the servo. But the fluid doesnt drop by a noticable amount to tell.

 

With the engine turned off, pump the pedal till its hard, hold it down then start the engine. It should sink to normal height, which says your servo is working.. But does sound like it got a leak somewhere. As David said, are you loosing brake fluid?

 

Yep, it does that ok, so that rules out the servo.

 

If you can rule out that it's not the seals then have you pressure bled the system? Because its a right PITA to get the air out of the ABS system. I bled mine 4 times and the pedal was still soft. Bought a Gunson Pressure bleed kit and with the use of a G -clamp pressure bled the system once and cured the spongyness immediately.

 

That was going to be my next purchase to try actually as i have a compressor here so could do that.

 

I do have a spare brake cylinder here to try so may give that a go tomorrow. Is there a seal between the servo and cylinder?

[kjgreen3]

If you buy this kit you don't need a compressor it uses the spare wheel or even your offside wheel to power the bleeding kit.

 

http://www.machinemart.co.uk/shop/product/details/tool-connection-eezibleed-kit/path/lubrication-fuel-transfer-equipment

 

Just make sure the cap will fit your reservoir. I had to modify mine and use a G-clamp to hold the cap onto my reservoir as my Supe is Jspec and the fitment wasn't universal. It may be ok on UK spec models though.

 

NB. As you are working with one of the best paint removal fluids and pressurising it!! I urge you to lay down towels or sheeting whilst carrying out this operation.

Edited September 11, 2010 by kjgreen3
Warning notice (see edit history)

[Steve]

If you buy this kit you don't need a compressor it uses the spare wheel or even your offside wheel to power the bleeding kit.

 

http://www.machinemart.co.uk/shop/product/details/tool-connection-eezibleed-kit/path/lubrication-fuel-transfer-equipment

 

Just make sure the cap will fit your reservoir. I had to modify mine and use a G-clamp to hold the cap onto my reservoir as my Supe is Jspec and the fitment wasn't universal. It may be ok on UK spec models though.

 

NB. As you are working with one of the best paint removal fluids and pressurising it!! I urge you to lay down towels or sheeting whilst carrying out this operation.

 

But then I will have to blow the tyre back up

 

Would rather get the proper bit of kit and use the compressor I have

[Graham S]

You got ABS? Have you bled the system with the engine running?

[Graham S]

But then I will have to blow the tyre back up

 

Would rather get the proper bit of kit and use the compressor I have

 

I have one of the compressor type brake bleeders your welcome to borrow anytime.. They ain't cheap if your thinking of buying just to use it the once.

[Steve]

You got ABS? Have you bled the system with the engine running?

 

Yep, car has ABS. I will try bleeding it with the engine running to see if that helps.

 

I have one of the compressor type brake bleeders your welcome to borrow anytime.. They ain't cheap if your thinking of buying just to use it the once.

 

Top man, thanks.