 | Home > Maintenance & Modifications > bleeding brakes... would it help to wedge the pedal down? |
 
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| donmacn Member Since: 06 Nov 2017 Location: Nth Scotland Posts: 1841  
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Hi,
So I know there's a lot of threads on this. Sorry. I hate bleeding brakes, because it never seems to be as straightforward as it should be. I have one of the eezibleed kits. I use a spare trailer wheel at 15-20psi, so plenty of pressure really. I open the bleed nipples, furthest to nearst, until there's no bubbles etc etc. But I still end up with a soft first pedal; good pedal on the 2nd press. So... what now? I should say - no leaks in the system; caliper bleed nipples the right way round - to the top. I'm starting to wonder about the master cylinder (though I see this is a common approach...). It's not 'old' (maybe 3 or 4 years) but not new either. I didn't fit it myself but it's possible it came in a blue box. Anyway, I can keep on trying and researching myself, but I wanted to ask a specific question - I know 'what' a master cylinder does, but not exactly how. Would it make any difference to the bleeding process if the pedal was wedged down while using the eezibleed? Clutching at straws? Donald 1994 Defender 300Tdi 110 SW - owned since 2002 - 230k miles and going strong (The 'rolling restoration' or tinkering thread: http://www.defender2.net/forum/topic58538.html ) 2000 Range Rover P38 4.0L V8 in the past.. RR classic - fitted with 200Tdi 1984 RR classic - V8 with ZF auto box 1993 Discovery 300Tdi not to mention the minis and the Type 2 VW camper... |
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21st Mar 2020 11:30pm |
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| donmacn Member Since: 06 Nov 2017 Location: Nth Scotland Posts: 1841
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Thanks BW,
Yes, I definitely should have said, it's a full set of Pioneer braided/flexi; and new calipers/discs/pads on the back. I know I should expect some spongy-ness with new stuff, but the first pedal is really soft - and then brilliant on the second, which to me really suggests there's air in the system somewhere. I wondered if pressing the pedal down would allow some air to rise all the way through to the reservoir? Donald 1994 Defender 300Tdi 110 SW - owned since 2002 - 230k miles and going strong (The 'rolling restoration' or tinkering thread: http://www.defender2.net/forum/topic58538.html ) 2000 Range Rover P38 4.0L V8 in the past.. RR classic - fitted with 200Tdi 1984 RR classic - V8 with ZF auto box 1993 Discovery 300Tdi not to mention the minis and the Type 2 VW camper... |
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21st Mar 2020 11:56pm |
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| discomog Member Since: 09 May 2015 Location: Notts/Lincs Border Posts: 2526  
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Rather than using the easibleed have you tried the good old fashioned method. It needs two people to do it, one to open and close the bleed nipple and the other to press down the pedal.
If you're not familiar with the old fashioned method then here it is in simple terms:- Open bleed nipple Someone else presses down the brake pedal (quickly) Close bleed nipple with pedal held down Once nipple is closed then brake pedal is released slowly. Repeat until there is no evidence of air bubbles. Then repeat the process on the other brakes Defender 90XS SW Mini Countryman Cooper S Morgan Plus 8 |
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22nd Mar 2020 9:16am |
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| Pilgrimmick Member Since: 16 Nov 2015 Location: Highlands Posts: 582
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I have used the jam the pedal down and leave for 48 hour method to get rid of a soft pedal that any amount of bleeding could bot shift.
It worked. I know it should not,and there is no explanation why it does, but has worked for me on several occasions, but only after conventional bleeding. 80" 1948 Lightweight V8 Bowler Tomcat 130 Station wagon 90 300tdi (Santana PS10 pick up) Range Rover L322 (Ful fat) |
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22nd Mar 2020 9:31am |
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| donmacn Member Since: 06 Nov 2017 Location: Nth Scotland Posts: 1841
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Thanks guys,
Yep - quite familiar with the traditional approach (but thanks for taking the time) it's just that I'm usually solo in the garage. But maybe worth a try - along with the wedged pedal. Our lad is on his way back from Uni. just now after all face to face tuition was stopped, so another possible helper. I've just been out for a spin; first pedal is pretty rubbish. If I was to press hard, I think it would stop the car - but not very quickly. The second pedal is really good - lots of bite and braking - even with all new brakes on the back. I'd be delighted to get to that as my standard, so at least I know I'm working towards a good system. Donald 1994 Defender 300Tdi 110 SW - owned since 2002 - 230k miles and going strong (The 'rolling restoration' or tinkering thread: http://www.defender2.net/forum/topic58538.html ) 2000 Range Rover P38 4.0L V8 in the past.. RR classic - fitted with 200Tdi 1984 RR classic - V8 with ZF auto box 1993 Discovery 300Tdi not to mention the minis and the Type 2 VW camper... |
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22nd Mar 2020 6:44pm |
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| white110 Member Since: 09 Dec 2017 Location: wales Posts: 10  
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I have had the same problem, irritating and a lot of waste Dot4.
One was an imperial/metric mismatch on replacement brake pipe allowing air back in. Another a wheel bearing slightly loose. Best of luck |
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22nd Mar 2020 7:31pm |
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| jst Member Since: 14 Jan 2008 Location: Taunton Posts: 8030 
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Have you fitted new discs/pads? They do need to bed in. Cheers
James 110 2012 XS Utility 130 2011 M57 bespoke Camper 90 2010 Hardtop 90 M57 1988 Hardtop |
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3rd May 2020 7:10am |
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| donmacn Member Since: 06 Nov 2017 Location: Nth Scotland Posts: 1841
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jst - yes, I have, but haven't had much of a chance to do any mileage recently!
But to be honest, I think I could live with bedding in issues. This is a little more than that. On the first press, the pedal is soft; on the second press it's fine - a firm pedal I'd be very happy with. This makes me think it's air in the system. I've used an eezibleed before, but I feel that the reservoir is a little small if I want to give the furthest away caliper a good 'drain", so just before the lockdown I got one of the sealey hand pump/pressure bottle things with a larger reservoir. So I'm hopeful that will make a difference. All of that said, I've been getting on with other stuff and "bleed brakes" keeps on dropping down my to do list! Donald 1994 Defender 300Tdi 110 SW - owned since 2002 - 230k miles and going strong (The 'rolling restoration' or tinkering thread: http://www.defender2.net/forum/topic58538.html ) 2000 Range Rover P38 4.0L V8 in the past.. RR classic - fitted with 200Tdi 1984 RR classic - V8 with ZF auto box 1993 Discovery 300Tdi not to mention the minis and the Type 2 VW camper... |
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3rd May 2020 9:14am |
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| blackwolf Member Since: 03 Nov 2009 Location: South West England Posts: 17382 
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Sounds just like a pre-facelift Disco2 fresh from the factory!
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3rd May 2020 10:15am |
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| jst Member Since: 14 Jan 2008 Location: Taunton Posts: 8030
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Take it for a short drive as is, then trebled furthest to closest. I normally do the two tears then refill the eezibleed reservoir then bleed that until the master cylinder level drops so you can get the cap on without it spilling. Approx 1.25l of fluid. Cheers
James 110 2012 XS Utility 130 2011 M57 bespoke Camper 90 2010 Hardtop 90 M57 1988 Hardtop |
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3rd May 2020 4:36pm |
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| donmacn Member Since: 06 Nov 2017 Location: Nth Scotland Posts: 1841
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Hey folks,
Going to try having another pop at this, and adding another element to the question. Tried bleeding the brakes today, with a new pressure bleedeer so I could happily run lots of fluid through. Furthest to nearest. No bubbles whatsoever that I could see. Now for the wrinkle - I'm wondering if there's a 'conflict' between my master cylinder and a brake bias valve that was fitted recently? The story is that the car was having some work, and an experienced person said: "Oh, you've no bias valve". TBH I don't actually know if the car ever had one (1994 110 300Tdi) but it would have been just the sort of corner to be cut by the bunch that did the last chassis swap last year, so with that in the back of my mind I didn't question the suggestion to fit one. Now I'm wondering if a standard 110 master cylinder does the biasing anyway; that there's no need for a valve and might never have been one; and that fitting the two could be causing some issues? There's maybe a logic in there - but it doesn't mean I'm right. If I'm right, then I could simplify the system and remove the bias valve. If I'm right, but that the perceived wisdom is that it would make no difference to the bleeding/spongy pedal, then I'll have to continue trying to find my answer elsewhere. Ta Donald 1994 Defender 300Tdi 110 SW - owned since 2002 - 230k miles and going strong (The 'rolling restoration' or tinkering thread: http://www.defender2.net/forum/topic58538.html ) 2000 Range Rover P38 4.0L V8 in the past.. RR classic - fitted with 200Tdi 1984 RR classic - V8 with ZF auto box 1993 Discovery 300Tdi not to mention the minis and the Type 2 VW camper... |
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5th Jun 2020 6:37pm |
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| Retroanaconda Member Since: 04 Jan 2012 Location: Scotland Posts: 2646 
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A 110 doesn’t usually have a bias valve however post-1991 all Defenders use the same master cylinder (ignoring ABS) so that can’t be your problem as 90s do use the valve.
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5th Jun 2020 8:34pm |
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| donmacn Member Since: 06 Nov 2017 Location: Nth Scotland Posts: 1841
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ah, Ok. Thanks very much. It's tempting to try and find 'the answer' so the brain scouts about looking for options.
Only next step I can think of is to put a litre or so of DOT4 through each corner, even if it means 'recycling' what is essentially new fluid anyway. It's only been in a matter of weeks, and little use. Still a brand new colour coming out of each caliper. This is on the assumption that there's an air bubble somewhere that needs pushing along and flushing out. If not that, then I don't know where to go next. The spongey first pedal/solid second pedal happens even just rolling out of the garage, so I don't think it's wheel or bearing wobble pushing the pads out. Servo was replaced with a quality one, probably in the last year and a half or so. If I turn it on its head, and assume that my bleeding technique is OK, then I suppose the next thing is to wonder if the master cylinder itself is going. It's not old, but it's not new either. What are the symptoms of a failing master cylinder? I've been thinking about this, and the servo was replaced in 2018, with this MC in place, so it's maybe older than I'd initially thought. The car stops OK, so I'm not concerned about taking it out, but I do wonder how it would fare under an MOT braking test. Donald 1994 Defender 300Tdi 110 SW - owned since 2002 - 230k miles and going strong (The 'rolling restoration' or tinkering thread: http://www.defender2.net/forum/topic58538.html ) 2000 Range Rover P38 4.0L V8 in the past.. RR classic - fitted with 200Tdi 1984 RR classic - V8 with ZF auto box 1993 Discovery 300Tdi not to mention the minis and the Type 2 VW camper... |
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5th Jun 2020 10:06pm |
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| roel Member Since: 08 Aug 2009 Location: Lelystad Posts: 2039  
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I had once a similar problem with my 90. Also after bleeding I kept the same symptoms as you.
After some driving it didn't became better so I pushes all calipers pistons completely in and wedged them with some wood. And left that overnight. In the morning the pedal was hard. Then I took the wood out and front to rear and the pedal stayed hard. I think that the air settled somewhere high and by pushing the pistons in the air came out on the top. Roel 1984 90 2.5 na Diesel - RR V8 (1994-2001) 1997 Camel Trophy Discovery 300TDI (2001-2009) 2005 G4 Discovery III 4.4 V8 (2008-2018) It's gone but it still hurts. 2003 90 Td5 (2009-now) |
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6th Jun 2020 3:33pm |
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