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Wow. Various reasons, huh? Pad wear; normal. Anything else; abnormal. Leaks, fractured hoses, hmm, what else? Oh, temperature; sure, that will change it if you have a microscope. If you want to play around with your safety that's your lookout. As someone who qualified as a motor mechanic, albeit a long time ago, I think I'll take my advice over yours. This particular comment is welcome to be read by geese.Quote:
Originally Posted by Andrew D
A goose wrote it.Quote:
Originally Posted by johntins
That works. My reply was to those who feel the need to draw fluid out of the cylinder, but if you hadn't topped it up you wouldn't have needed to.Quote:
Originally Posted by rick130
I'm curious, just what dirty **** do you think got into your sealed hydraulic system? Heat transfers throughout the system, and actually very little is transferred to the hydraulics anyway. Designers have had a whole century to work this stuff out.
Ask any brake mechanic and they will tell you that topping up is bad practice.
I used to work on a rally car. We used to mark the reservoir with a texta, for worn pads and new pads. It was a simple way to see if the pads had worn enough to change them. Not a big budget concern, you understand. However, I still do this on some cars, as it makes sense. Brake fluid does not evaporate, it doesn't go away. If you are losing fluid then you have a problem. Mere dropping of levels due to pad wear is nothing to worry about.
If your car flashed it's warning light then that's a fault in your car. It's a Land Rover, after all. I have never seen the brake warning light come on in any of my cars, except when there has been a fault. Low fluid due to pad wear is not a fault. Perhaps you needed to have yours checked as well.
All that said, I like to change brake fluid when I get the chance. The mineral type attracts water, which isn't good ( water boils at way lower temps than brake fluid, and then there's the corrosion..). Pretty sure the synth sort doesn't, but old habits die hard.
Gee, thanks for that insight. I am now aware that at least one utter fool read it. I am so glad that you are a contributor to a forum where most people get along and share ideas. You'll fit right in.Quote:
Originally Posted by Andrew D
Oh, and thanks for your intelligent rebuttal. All new ideas are welcome. Do you have any?
And I worked for several years professionally as a mechanic and setup engineer on race cars, but what's that got to do with anything?Quote:
Originally Posted by johntins
Except we'd bleed the brakes every meeting, as in a full fluid flush as glycol ether brake fluid is extremely hygroscopic and the heat/cool cycles draw moisture into the fluid.
Buckets of heat are directly transferred into the fluid through the pad backing plates and pistons, its how the fluid degrades.
It's also why things like ceramic pistons have been used, to reduce heat transfer and it's why high boiling point fluids were developed.
The boilng point drops badly with moisture absorption, and this leads to localised boiling and creates a soft pedal, microscopic bubbles forming and creating a longer pedal.
AFAIK only older Citroen's and maybe some RR's used mineral oil as brake fluid.
DOT3, DOT4, Super DOT4 and DOT5.1 are glycol ether based and extremely hygroscopic.
The general recommendation is a full flush every two/three years to maintain a reasonable boiling point and reduce corrosion.
In your case, nothing. I fail to see the relevance to my point. I was merely pointing out the correlation between pad wear and fluid levels, as, having read many of your posts, I'm sure you are aware.Quote:
Originally Posted by rick130
Sure, and perhaps bringing the rally car allusion into the discussion wasn't helpful. We're talking about a Disco here, a daily driver, and my rally stuff and your race stuff are not really on topic.Quote:
Originally Posted by rick130
Err, I already said that..Quote:
Originally Posted by rick130
So, tell me, are you in the "OH! WOW! OMG!! MY BRAKE FLUID IS LOW!" camp or not?? If you are, tell me why.
I'm in the "the low brake fluid alarm is ****ing me off even though the level has only dropped 1/4" so I top it off the M/C" camp. [biggrin]Quote:
Originally Posted by johntins
How does that contribute to the discussion? Understanding the car, the fluid needs of the car should have gone notwhithstanding. Golly, did I get that wrong?? I thought we were talking with people who had an idea. Mineral brake fluids were in use until a very few years ago. Many people on this forum are probably still using them. Sure, your unusual French fetish will change your perspective. I have an Italian one which changes mine.Quote:
Originally Posted by rick130
What I find odd in all of this is that NOBODY has been able to refute my position, apart from the abuse from someone from "Sydney". Not one. Come on guys, am I wrong? Lotsa mechs out there, did I screw up? Or, as I have laid out, am I right? Do not top up brake fluid. I'd like an answer from the guys who do it for a living.
Has it occurred to you that the sensor might be faulty? Do you drive something other than a Land Rover? If you do, does it beep and flash it's lights as the pads wear? My Ford doesn't, and neither it should. My D2 ( the car in question, look at the thread title ) does nothing of the sort, but my comments still apply. If you presented a car with a red brake light showing to any repairer in Victoria they would not let you drive it away.Quote:
Originally Posted by rick130
Top it up as you please. It's obviously your choice. However, next time you are in getting your brakes done, ASK them. And then go to the paint guys and try and get them to fix the paint where the brake fluid has ****ed it because it has overflown due to you pushing back the pistons of your calipers when you changed your pads.
Your choice.