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Bleeding Wilwood calipers. Again!
rdodger - 4/3/13 at 07:36 PM

Evening all.

I have searched and read a lot about this.

So far I have:


Bled the master cylinder. Left a soft pedal.
Checked the alignment with the discs. Soft pedal.
Vacuum bled. Left a soft pedal.
Manually bled. LASP.
Pressure bled with eezibleed. LASP.
Gravity bled. LASP.
Removed calipers, pushed the pistons half out onto wood spacers. Bled again. LASP.

Currently have the calipers suspended above the car, above the master cylinder with the eezibleed keeping it all under pressure. I plan to turn them and bleed every 12 hours or so.

Anything else I can do? I am pulling my hair out!


theprisioner - 4/3/13 at 07:41 PM

I suppose it won't the obvious, I did on my Willwoods and had a similar result to your experiance. My Midlites have 4 nipples, I only saw the inner ones when I came to bleed the brakes Daaaaaa.........


Wadders - 4/3/13 at 07:56 PM

Try using the eezybleed again, but unbolt the calipers and play about with them as you bleed
i.e turn them upside down and on their side etc, nip the bleed nipple up and then repeat a time or two
it's amazing how many air bubbles you can coax out.

Al.


ashg - 4/3/13 at 08:35 PM

what master cylinder do you have? also have you fitted one of those brake light pressure switches? if you have bin it and put a plug/bleed nipple in its place then fit a micro switch to the pedal. could never get a good pedal with one of those pressure switches in the system.


rdodger - 4/3/13 at 08:38 PM

Fiat 126 master cylinder. (pics on the master cylinder thread)

I don't have a pressure switch. I have a plunger on the pedal.

Any other ideas?


mark chandler - 4/3/13 at 09:02 PM

Clamp each flex pipe in turn and localise, if you end up with all flex pipes clamped and a soft pedal look towards the master cylinder


rdodger - 4/3/13 at 09:33 PM

I have braided hoses so I believe I can't clamp them without damaging them?


ashg - 4/3/13 at 09:38 PM

any chance the mc was from brakes international? they sent me a duff brand new one, sent it back and they said it was fine and wouldnt give me my money back. ordered a new one off a chap on ebay and the problem magically went away!


Jimfin - 4/3/13 at 09:56 PM

Using new quality branded brake fluid from a sealed can?


Westy1994 - 4/3/13 at 10:05 PM

I ran some years ago and on another car Wilwoods, I had issues as well, removing to get them higher than the master cylinder was the cure, but really should not been necessary. Can you blank off the master cylinder to make sure its not that , if bleeding by all means does not work?.


rdodger - 4/3/13 at 10:13 PM

Not sure on the source of the MC as it came with the kit.

It was new to start with. I will go and get some new fluid tomorrow and flush through. It's been round and around a few times so probably a good idea.

I will bleed them above the MC, tapping and rolling as I go.

Fingers crossed!


Oddified - 5/3/13 at 08:58 AM

Is it possible that the soft peddle is because you'll have new pads/disc's which aren't bedded in. More often than not that will also make the brakes feel like there's air in them until they've done a few miles.

Ian


maccmike - 5/3/13 at 08:59 AM

unscrewing and blanking the mc where the pipes screw in will diagnose if its the master cyl.
make sure youve got ptfe tape on the nipples, surprising how much air get sqeeze through when bleeding


adithorp - 5/3/13 at 10:17 AM

You have bled from both top bleed nipples haven't you? Someone on here posted similar recently and had only bled from one nipple.

If not that would you like me to come and give you a hand. Bleeding brakes is one of those things that gets easier when you've done it a thousand times.


rdodger - 5/3/13 at 06:29 PM

Hi Adi

Yes I have bled inner and outer nipples.

Over night I had the calipers as high as poss and got some air out today when I ran the new fluid through. I will bleed again tomorrow and refit them. Fingers crossed!

If no improvement you may well get a call for help Adi.


britishtrident - 5/3/13 at 07:42 PM

If you use more than about 300ml bleeding a system something is wrong. You can often encounter leaks in the system where there is no apparent fluid leakage but air is drawn back into the system, so the first task is to go round every joint on the system and examine it while an assistant keeps the system under pressure -- to be extra sure tighten up every joint. Note this includes the joints on the flex hose assemblies. In the past have encountered braided hoses that were faulty out of the box so don't assume because they are new they are OK.

If that doesn’t work you have track down where the spongeyness is as you have braided flex hoses the only way to do this is by disconnecting pipes and inserting bleed nipples to blank off outlets.

I would start by fitting bleed nipples into the front T piece and giving the front circuit a single pump bleed. if you get a solid pedal you know the problem is between the front T and the front wheels.

If no improvement try the same at the rear.

If still no improvement test each circuit by screwing bleed nipples directly into the master cylinder ports.

[Edited on 5/3/13 by britishtrident]


rdodger - 5/3/13 at 09:50 PM

Thanks for the advice.

I have got some air out today so am hopeful it will be ok. If not it looks like I need to order some bleed nipples.


rdodger - 6/3/13 at 05:16 PM

Update

Well it is a lot better! Phew!

It's not rock hard but I am putting that down to the pads/discs being new and not bedded in. I guess time will tell!


jossey - 8/3/13 at 12:46 PM

Are the wheels on when you bleed them in other words are the discs free to move give the feeling off soft pedal.


INDY BIRD - 8/3/13 at 02:01 PM

Also check no air trapped in the brake light switch as can happen. Just undo a small amOunt to bleed, I found it best
To pumP the peddle and hold it down over night with a device Ie I used a broom and then try each one as pushes all the air
To the caliper


rdodger - 8/3/13 at 05:30 PM

quote:
Originally posted by jossey
Are the wheels on when you bleed them in other words are the discs free to move give the feeling off soft pedal.


Good point.

The wheels were off the car. I did try it with the wheel nuts on tightened to the discs. I will pop the wheels on tomorrow and see if it firms up some more.


jossey - 9/3/13 at 07:21 PM

quote:
Originally posted by rdodger
quote:
Originally posted by jossey
Are the wheels on when you bleed them in other words are the discs free to move give the feeling off soft pedal.


Good point.

The wheels were off the car. I did try it with the wheel nuts on tightened to the discs. I will pop the wheels on tomorrow and see if it firms up some more.



They will just make the pedal feel soft...

Let me know how it goes...


Yodaknowscncs - 28/3/13 at 10:12 PM

Hi,

Have you consider that you might not be shifting enough brake fluid into your new wilwoods, were your old calipers twin pots and the wilwoods 4 pots, using larger pistons acting on the discs, thus the mc doesn't have enough fluid inside it to generate the pressure needed?

Cheers