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After my most recent self repair job of changing the rear pads I took the top off the brake fluid reservoir and noticed the fluid looked a bit cloudy. So its got me wondering just how long it's been in there. I have no issue with the effectiveness of the brakes but I'm thinking that maybe a flush through with some fresh stuff wouldn't go a miss. Unless you guys inform me otherwise.

I'm ok with undertaking the job as i worked as a mechanic when I first left school many moons ago. The only thing that concerns me is that I carry round the information that I learnt about 20+ years ago which is probably somewhat out of date now. ie - I was always led to believe that when bleeding brakes you run the risk of the brake master cylinder rubbers collapsing because of depressing the brake pedal to its full limit which of course is alot further than its normal range of travel. This may or may not be true but it's what I was taught while training as an apprentice so I don't know any different.

So I put this question out to you guys who maybe have experience of this. Is it worth doing, what are the risks to look out for and is there a set seqsequence to follow-

eg- start with the wheel furthest away from the brake master cylinder then the 2nd etc etc?

As always, any advice greatly appreciated
 

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^^^...This,also brake fluid is hydroscopic(absorbs moisture)the more moisture in the fluid the lower the boiling point becomes..Fluid gets hot,moisture starts to evaporate creates an air bubble within the fliud..
 

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Discussion Starter #4
I've had a look on you tube about the vacuum tool. Is this the only fool proof way of bleeding the brakes? What would happen if they were bled without a vacuum tool and the ABS disabled?
 

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Ok, I apologise in advance because this thread is 5 years old but it is still very relevant.

So today for the very first time, I actually swapped out the brake fluid in my Saabillac. Haynes manual gave me the correct bleeding sequence and I cracked on thinking this was going to be a straightforward job. I bought a vacuum bleed kit so I didn't have to muck about getting anyone else to pump the pedal etc.

First off, I disconnected the negative terminal on the battery. I then extracted as much of the old fluid from the reservoir using a turkey baster. Refilled the reservoir with clean Dot4+ and set up my bleed kit and went for the nipple, and that is where it started to get very very tricky. So of course the bleed nipple was seized. I drenched it with Plusgas and left it to soak whilst moaning to myself about what might happen if the bloody nipple snapped off. Anyway, it took me almost an hour of gentle tapping and wriggling the bleed valve with a pair of mole grips, yes, yes I know that's not what I should have been using, but unfortunately not a single spanner or socket I owned would fit it properly, so I had to clamp it as tightly in the jaws of the moleys as I could. Eventually, it gave and very slowly and carefully, I got it cracked open and the fluid duly ran into the container under pressure. Yup, it was a bit mucky, cloudy and it had bits in it, but it eventually ran clear with no bubbles.

And so that continued with the other 3 bleed valves. A bit of a bloody nightmare if I'm honest, but I got there in the end. I ended up using an entire litre of brake fluid, but at least the whole line system is now clean.Test drive went ok and car stops as it should.

My issue now is, I reckon I'm going to have to change my rear brake calipers for refurbished ones. They aren't in a great state even though they do work, but I noticed that slider pin rubber guide bushes are deteriorating and the last time I had the discs and calipers off, there was some pretty awful pitting and corrosion on the piston faces. I've priced up a new pair and I'm looking at £70 for the pair and that includes new slider pins. I might just change the brake hoses too.
 
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