Brake bleeding

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OXO
Joined: Wed 31 Mar, 2010 08:32
Posts: 567

  Z3 roadster 2.2i
Location: France

Brake bleeding

Post by OXO »

I have to do all my maintenance alone, and brake bleeding needs 2 people the old way.

I've been looking at a better way. Does anyone have experience/ recommendations for a kit?

There are lots on ebay..

http://www.ebay.co.uk/sch/i.html?_trksi ... &_from=R40
Mowerman
Joined: Fri 04 Oct, 2013 13:12
Posts: 38

  Z3 roadster 2.2i
Location: Horsham

Re: Brake bleeding

Post by Mowerman »

I`ve used the Gunsons Eezibleed in the past with good results, but not yet on the Z. You would need to ensure the kit contains the right size cap! Cheers, Steve.
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OXO
Joined: Wed 31 Mar, 2010 08:32
Posts: 567

  Z3 roadster 2.2i
Location: France

Re: Brake bleeding

Post by OXO »

Mowerman wrote:I`ve used the Gunsons Eezibleed in the past with good results, but not yet on the Z. You would need to ensure the kit contains the right size cap! Cheers, Steve.
Thanks Steve, this one says it does not require special caps..

http://www.ebay.co.uk/itm/NEW-BRAKE-CLU ... 565f54b549
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Mint
Joined: Tue 01 Nov, 2011 18:43
Posts: 475

  blank

Re: Brake bleeding

Post by Mint »

Mowerman wrote:I`ve used the Gunsons Eezibleed in the past with good results, but not yet on the Z. You would need to ensure the kit contains the right size cap! Cheers, Steve.
I bought this Gunsons Eezibleed from Amazon earlier in the year and it came with the right size cap for my Zed.

http://www.amazon.co.uk/dp/B001KTFIWA/r ... _M3T1_dp_1
Mike Fishwick
Joined: Fri 19 Jun, 2009 10:27
Posts: 2093

  Z3 roadster 2.8
Location: Daglan, France

Re: Brake bleeding

Post by Mike Fishwick »

I have used a Gunsons Ezibleed for about twenty years, with no problems. I use an old emergency spare wheel as a source of compressed air, which is good for bleeding 2 calipers, and I get through a litre of dot 4 brake fluid while changing the fluid and bleeding the clutch slave cylinder. It is so easy to use that I do this every two years. I buy ATE fluid from German and Swedish, alternately using clear or blue fluid, so I can see when all the old fluid has been removed from each brake line.

Image

A lot of people do not realise that a pressure bleeder is essential for bleeding twin-circuit brakes, for if using the 'tradional' method the first circuit to be purged of air will become 'hard' and prevent the pedal fom being fully depressed - so preventing the second circuit from being properly bled.

On the subject of pressing the pedal, on a high-mileage car the master cylinder bore may have a small step worn in it, at the normal limit of travel - when a bleed nipple is open it can be fully depressed, an action which may damage the lip of the seal against the step. For this reason it is wise not to press the pedal while bleeding the brakes - and of course you do not need to anyway, when using a pressure bleeder.
A Z3 is not just for Christmas - it's for life!
Del
Joined: Sat 19 Nov, 2011 18:35
Posts: 2136

  Z3 roadster 1.9

Re: Brake bleeding

Post by Del »

I've used the Gunsons kit myself on several different cars and it's worked fine. The kit in the link above talks about needing "workshop" air pressure of 90-120 psi which would not fit with most DIY usage.
Del
Joined: Sat 19 Nov, 2011 18:35
Posts: 2136

  Z3 roadster 1.9

Re: Brake bleeding

Post by Del »

Forgot to mention, my Haynes says that the system should not be pressurised beyond 29 psi as "higher pressure will damage the reservoir".
pedro20001
Joined: Sat 29 Jan, 2011 20:34
Posts: 361

  Z3 roadster 2.2i
Location: tamworth

Re: Brake bleeding

Post by pedro20001 »

try screwfix for gunsons eazibleed; cost me £15 ish earlier on this year
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OXO
Joined: Wed 31 Mar, 2010 08:32
Posts: 567

  Z3 roadster 2.2i
Location: France

Re: Brake bleeding

Post by OXO »

Del wrote:I've used the Gunsons kit myself on several different cars and it's worked fine. The kit in the link above talks about needing "workshop" air pressure of 90-120 psi which would not fit with most DIY usage.
Thats not an issue as I have a big compressor. My inclination is to get one like that as it will be less hassle than messing about with spare wheels.
Mike Fishwick
Joined: Fri 19 Jun, 2009 10:27
Posts: 2093

  Z3 roadster 2.8
Location: Daglan, France

Re: Brake bleeding

Post by Mike Fishwick »

Too high a pressure can cause the master cylinder to pop out of its mounting grommets, spraying fluid all over the place - the Gunsons unit suggests 20 psi, which is easy enough to produce with a footpump in a spare wheel. A real wheel would probably handle a full bleed, rather than a comic emergency type.
A Z3 is not just for Christmas - it's for life!
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OXO
Joined: Wed 31 Mar, 2010 08:32
Posts: 567

  Z3 roadster 2.2i
Location: France

Re: Brake bleeding

Post by OXO »

This is the one I'm thinking of getting Mike. It connects to the bleed valve and sucks the fluid through, so the reservoir is never pressurised.

Looks like it makes a vacuum by passing compressed air through a Venturi.

http://www.ebay.co.uk/itm/370966924860? ... 1423.l2649
Brian4
Joined: Mon 19 Dec, 2011 19:02
Posts: 541

  Z3 roadster 3.0i
Location: Hinckley

Re: Brake bleeding

Post by Brian4 »

Brake bleeding is ok using these low pressure systems but for a brake fluid change the ABS pump has to be cycled to replace the fluid in it. This is best left to a specialist with the software or if you have the diagnostic software it is DIY.

Another reason for not pumping the pedal is that it usually goes past the master cylinder piston's normal use position and any corrosion in the master cylinder can get into the brake fluid and possibly the ABS pump and cause problems.
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c_w
Joined: Thu 19 Aug, 2004 16:50
Posts: 4032

  M roadster S50

Re: Brake bleeding

Post by c_w »

I wouldn't worry about the fluid in the ABS unit, if the fluid is changed regularly it won't stagnate in there, though you can manually trigger the pump if needed.

Generally the reservoir is only just slotted on with rubber bungs so 90psi or so will surely blow that off! Generally bleeding can be done naturally just with the bleed nipples open, so a nice 20psi or so push through is plenty.
fish
Joined: Thu 07 Feb, 2013 17:04
Posts: 177

  Z3 roadster 2.2i
Location: Sandbach, Cheshire

Re: Brake bleeding

Post by fish »

Hi,
Am about to remove my calipers to refurb them…..I assume I can "just" remove them, albeit with the hoses clamped…?

I have a gunsons eezi bleed kit, so was assuming I dont need to worry about that of course until I refill the system…

I had pondered using the kit to empty the system out totally and refill at a later date, but assumed that was daft, as it would bring in air, moisture and at worst corrosion etc to the inside of the system…..OR is it normal and OK to drain the system totally and just refill come new caliper time….
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Brian H
Joined: Tue 16 Dec, 2008 19:55
Posts: 2505

  Z3 roadster 3.0i

Re: Brake bleeding

Post by Brian H »

I would just remove the calipers with the hoses clamped then flush fresh fluid through the system with the calipers reinstalled. No need to empty the system.
Mike Fishwick
Joined: Fri 19 Jun, 2009 10:27
Posts: 2093

  Z3 roadster 2.8
Location: Daglan, France

Re: Brake bleeding

Post by Mike Fishwick »

I do not like the idea of clamping hoses, as particularly if they are old, can start to break up internally. Hoses need to be replaced after a few years anyway.

Even with new-ish hoses, I would prefer to buy four M10 x 1 threaded hose couplings, which will screw onto the hoses, and can be sealed at their other ends with bleed nipples until the calipers are replaced.
A Z3 is not just for Christmas - it's for life!
fish
Joined: Thu 07 Feb, 2013 17:04
Posts: 177

  Z3 roadster 2.2i
Location: Sandbach, Cheshire

Re: Brake bleeding

Post by fish »

Mike Fishwick wrote:I do not like the idea of clamping hoses, as particularly if they are old, can start to break up internally. Hoses need to be replaced after a few years anyway.

Even with new-ish hoses, I would prefer to buy four M10 x 1 threaded hose couplings, which will screw onto the hoses, and can be sealed at their other ends with bleed nipples until the calipers are replaced.

http://www.ebay.co.uk/itm/Bleed-nipples ... 4aaca11f25

So bang in these bad boys then….haven't got clamps yet so these make a cheaper alternative, sensible too….so I guess I just undo the rubber hoses and they should marry up/in….
Last edited by fish on Fri 21 Feb, 2014 21:24, edited 1 time in total.
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t-tony
Joined: Sun 21 Feb, 2010 23:17
Posts: 353

  Z3 roadster 2.0
Location: torksey lock

Re: Brake bleeding

Post by t-tony »

You beat me to it there Mike, been using that fix for nearly 40 yrs. Last year I used some old bleed screws to block the ports in my callipers while they were painted too. Also it's worth having some male and female pipe nuts with a short piece of pipe flared and then flattened and bent over leaving the flare in the nut to use as blockers. We have a pressure bleeder at work which you hand prime to 15 psi connected to the master cyl. via a reservoir for brake fluid changing. Supplied by MAC Tools. approx. £65.
"Knowledge and experience are not always the same"
Mike Fishwick
Joined: Fri 19 Jun, 2009 10:27
Posts: 2093

  Z3 roadster 2.8
Location: Daglan, France

Re: Brake bleeding

Post by Mike Fishwick »

Another car where a pressure bleeder is essential is the old Mini, where the rear brake cut-off valve used to shut off the rear brakes very easily when bleeding the old-fashioned way. There must have been lots of Minis around with the rear brakes full of air after a slave clinder had been changed!
A Z3 is not just for Christmas - it's for life!
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