Bleeding brakes!!

[nedflanders]

TD5 90 2003 ABS
I started to get a soft brake pedal about a month ago, not bad but something not quite right, 1 pump and it's OK until I next use them. I bled them through a month ago as the fluid was getting old and had a really good pedal, until now and it's started to go soft again. Must have bled 2 litres through it. No signs of leakage and the pads are new. Any ideas?

[djam1]

Did you bleed the modulator??
They have a lot of small air pockets in them that are difficult to get all of the air out of.
You may need a Nanocom or Hawkeye to bleed the modulator properly.
That said I have never HAD to do it just found it easier

[jboot51]

Just a heads up,
A loose/bad wheel bearing will cause the pads to knock back, giving the feeling of bad brakes on the first push and ok on the second.

[nedflanders]

No problems with bearings or brake discs?? No reason why any air should have gotten in the system??? :( plus after bleeding its ok for a few weeks, anything like bearings/discs would be fairly immediate.

[460cixy]

New pads on old rotors will give a **** pedal

[Flipper]

TD5 90 2003 ABS
I started to get a soft brake pedal about a month ago, not bad but something not quite right, 1 pump and it's OK until I next use them. I bled them through a month ago as the fluid was getting old and had a really good pedal, until now and it's started to go soft again. Must have bled 2 litres through it. No signs of leakage and the pads are new. Any ideas?

My gut tells me the master cylinder needs repair from your description.
I have seen this symptom all to often which normally shows the master cylinder is stuffed.
Worth checking all other things over first but my money is on the master cylinder.

[Backtabush]

If its showing air bubbles in the system when you bleed it i would say master cylinder getting tired each time you release the pedal as it return back the rubbers cups are not under pressure and very small amount of air can be drawn in thru rear cup seal and may not show sign of leak yet mine got 270ks up and just starting to bypass when pulling up at lights under light pedal pressure you feel the pedal travel more than under normal braking or if your sitting at the lights and you relax the pressure a bit you feel the pedal start to creep towards the floor you know to start shopping around.

[Lorryman100]

A quick test you can do to see if the Modulator needs bleeding is to get the TC or the ABS to operate. Loose gravel, beach sand and shingle are idea. If after the ABS/TC operates and the pedal firms up, then you have your answer. If this is the case then you will need to do a Master cylinder bleed first followed by bleeding each caliper starting with the furthest from the modulator and finishing with the closest. The other option is to use a diagnostic tool to operate the modulator pump.


HTH Brian.

[nedflanders]

New pads on old rotors will give a **** pedal

As long as the rotors are good then no, gotta disagree, seriously do you change rotors everytime you change the discs??

Kinda agree with the master cylinder, prices over here are once again taking the **** so another order back to UK. Genuine UK £190 or Aus $800+ LOL!!!

[460cixy]

As long as the rotors are good then no, gotta disagree, seriously do you change rotors everytime you change the discs??

Kinda agree with the master cylinder, prices over here are once again taking the **** so another order back to UK. Genuine UK £190 or Aus $800+ LOL!!!

It don't work like that the rotors not flat. You put new pads in that are flat and what do you think is going to happen? They just bend out of shape every time you stand on the brake I see it all the time customer puts new pads in car won't stop they come in and can't beleave its there me pads giving them a **** pedal it may not be your problem but it sure as **** happens

[nedflanders]

I understand there is a 'bedding' in period when changing pads, I also understand that putting new pads on warped/scored or worn out discs is stupid, what I don't understand is how after bleeding I had a good pedal for a month and now it's getting soft again. I'm sorry but if what your saying is right then once the pads are 'bedded' in then I should have a good pedal therefore the softness should be getting better if anything.
What ****es me off is garages trying to fleece customers for new rotors/discs when all that's required is a bedding in period.
Where do you work??

[460cixy]

Firstly as I said in the last post I don't think this is the problem your haveing but in your original post you stated you had new pads and I was makeing you aware this can cause a low pedal. As for fleecing customers I'm sure some places do. But we won't warent our work for NOISE if the rotors are not machined or replaced depending on what's required. And the law states rotors on or below min thickness must be replaced. And no I'm not telling you where I work but brakes is what we do

Here's good example of what most ppl think is an ok rotor and just slap pads in and wonder why the pedal goes to the ****ing floor


https://www.aulro.com/afvb/images/imported/2013/07/294.jpg (http://s48.photobucket.com/user/460cixy/media/image_zps1ce06e29.jpg.html)

And I've had plenty of customers argue and call us ****s and say we are ripping them off because to them they think a rotor like that is a ok I see it day in and day out

[nedflanders]

I agree with you that some people wouldn't know what a good or bad rotor looks like, luckily I do. I have never seen a pedal go soft over the course of a month because of new pads on old rotors (I'm not talking worn out or scored I'm talking rotors on there second set of pads!!) Having to deal with the public is something I don't envy you, I did for awhile and know there are a lot of people that know a lot about **** all!! or try and scam free work or parts by kicking up a fuss.

[Carslil Jim]

Long shot. It seems to me you may be getting air into the system. Where air can get in, fluid can get out so take a look for any signs of seepage on any of the connections.

This works for diesel engines which wont start if air is in the system, so maybe it will work for brakes too.

[Blknight.aus]

how certain are you its not the master cylinder recirculating untill you get to a certain point in the piston or a certain pressure level?

[mattmason1]

Hey Ned, where did you get quoted £180 for the master cylinder? I have a 90 of the same vintage and here in Perth also. Having the same problems with mine and I suspect a leaking M/C.

I've used my Nanocom Evo on power bleed, with some improvement, but still not perfect!

[nedflanders]

Paddocks are £190 plus delivery which shouldn't be too much, I think they get them direct from LR. Main dealer in Perth quoted $1000+ and over a week to get from over East?? Doesn't make sense to me at all?? I'm leaning towards MC as ABS modulator doesn't bare thinking about :eek:

[460cixy]

I agree with you that some people wouldn't know what a good or bad rotor looks like, luckily I do. I have never seen a pedal go soft over the course of a month because of new pads on old rotors (I'm not talking worn out or scored I'm talking rotors on there second set of pads!!) Having to deal with the public is something I don't envy you, I did for awhile and know there are a lot of people that know a lot about **** all!! or try and scam free work or parts by kicking up a fuss.

Sweet as long as we know where we stand here and dealing with the public is the worst part of the trade

[mattmason1]

Master cylinder ordered from Britcar - it'll be hear from the UK faster than it would if it came ex-east! I'll keep you posted!

[460cixy]

how certain are you its not the master cylinder recirculating untill you get to a certain point in the piston or a certain pressure level?


And this could also be the problem but bloody hard do diagnose even when it's in the workshop but normally with light pressure it will just creep away maybe to the floor or half way depending what circuit is by passing but it won't be low all the time

[460cixy]

Now thinking back to an Astra I did a few weeks ago it went to two workshops before me and no one could get a pedal I used the scan tool to bleed it throu the abs plus a pressure bleeder screwed on to the master and bingo full pedal. And not haveing too many landys come throu work and our bosh tool won't talk to them any way. Can you use nanocom ect to to bleed the brakes?

[mattmason1]

Yes, you can use the Nanocom to bleed the brakes. I've used it on mine and still get the pedal going to the floor, hence the be master cylinder on its way to me as we speak!

[harro]

Yes, you can use the Nanocom to bleed the brakes. I've used it on mine and still get the pedal going to the floor, hence the be master cylinder on its way to me as we speak!

Just had a look at this thread.
I hope you have checked the booster for vacuum leaks.
Your symptoms don't really point to this but certainly worth checking.

Cheers,
Paul.

[nedflanders]

Ordered a MC, bled the brakes again today and back to a decent pedal. Most of the air was in the calliper furthest from ABS modulator. Do I need to power bleed once I fit the MC or I've been using a suction one at work that uses an airline to suck the air/fluid out of the calliper?

[460cixy]

If its got a good pedal I would leave it alown

[nedflanders]

If its got a good pedal I would leave it alown

The problem is the pedal slowly deteriorates over the course of a few weeks, hence the need for a new MC. :(

[460cixy]

Ahh sorry I read that wrong I thought you had fitted a new mc already bloody dyslexic

[mattmason1]

@nedflanders, if you want to borrow a Nanocom, I have one. Happy to help out, but I'm back at work tomorrow and won't be back until next week. That should help you do the power bleed.

Matt.

[nedflanders]

Cheers for the offer Matt :) still waiting on Paddocks to pull their finger out :(

[nedflanders]

Well after finally receiving my master cylinder and borrowing a nanocom (cheers Matt, need to get my own and its next on a very long list!) I thought I'd have a Defender day, as well as changing the master cylinder I sorted out an annoying handbrake switch (involved adjusting the outer handbrake cable, a pain in the arse!) changing the fuel filter and changing the glowplugs (surprisingly easy!!)

Bleeding the brakes however was a nightmare, even with the nanocom I just couldn't get a decent pedal, took about 5 attempts bleeding the whole system to sort it, hopefully its cured my spongy pedal (after a week), time will tell!!