Bleeding brakes...now spongy pedal

[Poperon]

Hi,

2006 Doblo Multijet, Discs front, drums rear, ABS.

Well overdue for brake fluid replacement.

Good news is that there was only a bit of discoloured/contaminated fluid that needed to be bled out (front discs).

The not so good bit is that I've somehow managed to do something leaving the pedal feeling a bit spongy.

Here's what I did: First of all tried an old brake bleeding kit, which is a replacement reservoir cap connected up to a pressure vessel (with pressure gauge), the cap wasn't a good fit it leaked air and for some reason the level in the reservoir went up when pressure (10psi) was applied (did I put some air into the system by accident at this point?). Gave up on that and did the rest of the job with the pump and hold method.

I know I must have introduced some air to cause the sponginess, my question is how to get it out? Should I just keep on bleeding until the air finally works it way through the system? "Pump & hold" method or should I get hold of a more up to date bleeding kit with integral fluid reservoir (Gunson Eazibleed type).

Any suggestions much appreciated.

Cheers

Ron

 

[Trustme]

Hi,

2006 Doblo Multijet, Discs front, drums rear, ABS.

Well overdue for brake fluid replacement.

Good news is that there was only a bit of discoloured/contaminated fluid that needed to be bled out (front discs).

The not so good bit is that I've somehow managed to do something leaving the pedal feeling a bit spongy.

Here's what I did: First of all tried an old brake bleeding kit, which is a replacement reservoir cap connected up to a pressure vessel (with pressure gauge), the cap wasn't a good fit it leaked air and for some reason the level in the reservoir went up when pressure (10psi) was applied (did I put some air into the system by accident at this point?). Gave up on that and did the rest of the job with the pump and hold method.

I know I must have introduced some air to cause the sponginess, my question is how to get it out? Should I just keep on bleeding until the air finally works it way through the system? "Pump & hold" method or should I get hold of a more up to date bleeding kit with integral fluid reservoir (Gunson Eazibleed type).

Any suggestions much appreciated.

Cheers

Ron

some clear pipe that has a tight fit over the bleed nipple and a tub with some brake fluid in it, put the pipe over the bleed nipple, place the pipe in the tub making sure it is submerged in brake fluid, remove the cap from the brake fluid reservoir and make sure it is full, loosen the bleed niggle and short sharp pumps making sure the reservoir never gets low and once air is out tighten bleed nipple

 

[Poperon]

Hi, thanks.

That sounds like the "Pump & hold" method. Am I better off with that method or will a bleeding kit with reservoir be better for getting the last bubbles of air out?

Cheers

Ron

 

[s130]

After bad experiences in the past, like your Easybleed? pressure bleeding and pump and hold issue, I now only bleed brakes with the assistance of a pedal pusher.

The advantages of this are:

1) you can examine the fluid, bubble content etc. whilst the fluid is being expelled

2) you can close the brake nipple on the "pedal down stroke" which ensure no air is drawn in or allowed leak in during the pedal up stroke.

On modern ABS brake systems once air has entered the system then it takes a lot longer and more fluid to completely expel all the air.

 

[Poperon]

Thanks,

The main thing for me is to get all that pesky air out the system and if takes a bit more pumping fluid through and perseverance using the pedal pusher method then that's probably what I've got to do.

I see there are also vacuum tools which suck the fluid out at each bleed nipple, out of interest are these any good?

Cheers

Ron

 

[s130]

I see there are also vacuum tools which suck the fluid out at each bleed nipple, out of interest are these any good?
Ron

I've seen these suction bleed kits.

I believe they work quite well (I've never used one) but I also believe that for 100% reliable results one has to change your standard brake nipples for ones with integrated 'O' ring.

The problem with standard brake nipples is that the only air tight situation is when the nipple is closed off. When open air can get back into the system via the nipple threads.

On a suction system then whilst fluid will be sucked out of the brake system the problem one can have is that at the suction end air can be pulled in via the nipple threads. Being a suction system this air can not get back into the braking system however you end up with a clear suction tube with aerated drawn fluid which can make it difficult to determine when to stop sucking.