View previous topic :: View next topic |
Author |
Message |
colint Gate Opener
Joined: 26 May 2002 Odometer: 34
|
Posted: Thu Apr 24, 2008 1:28 pm Post subject: Air in the brake fluid - please help!
|
|
|
Hi
I have a 1990 ex Mod 110. I started by just changing the rear brake shoes. Unfortunately, as often happens, one job lead to another. I have now replaced both rear shoes and slave cylinders, one front caliper and the master cylinder!
My problem is that I cannot get the air out of the system! I have now put at least 5 litres of fluid through the system, but am still getting lots of air bubbles out when I bleed the front right caliper (the only part I haven't changed). I did try the eezebleed, but since I had no success at clearing the air out of the system, I wondered if that may be adding more air so I've now gone back to the old fashioned manual way as described in the workshop manual. To be clear, this is what I am doing:
The master cylinder is topped up (regularly) to full with new fluid. I attach a clear tube to the bleed nipple of the front right caliper - the one closest to the master cylinder. The other end of the tube is placed into the fluid of my drain container (my wife's best Pyrex measuring jug - shhhh!). I open the bleed nipple slightly - about 1 flat of the spanner. My helpful assistant then presses down quickly on the brake pedal, pauses, lets the pedal come up, pauses, then repeats. She continues this for some considerable time, until we stop to empty the jug, or top up the master cylinder. When we stop, I ensure that I close the nipple whilst the pedal is down. On each press down of the pedal, I can see fluid containing many many tiny air bubbles shooting out of the drain pipe.
As I say, we have put 5 litres of fluid through the system - 2 litres using the eezebleed, and a further 3 litres manually, and still the fluid coming out contains air!
With all nipples closed, the brakes are low, and can be pumped up using the pedal to their normal height which supports the fact that there's air still in the system.
Any suggests please?
Many thanks in anticipation.
|
|
Back to top |
|
|
|
doris Just got MTs
Joined: 23 Sep 2005 Odometer: 305 Location: Chippenham
|
Posted: Thu Apr 24, 2008 2:01 pm Post subject:
|
|
|
Hi
I may be wrong, but I didn't think you were supposed to let the pedal come up with the nipple open. When I bleed mine I have my assistant push the pedal down and hold it, then I close the nipple before they release the pedal, opening the nipple again for the subsequent downstroke. Have not had any problems doing it this way.
Damon
|
|
Back to top |
|
|
steve:h Articulating
Joined: 31 May 2006 Odometer: 598 Location: darkest derbyshire
1996 Land Rover Discovery
|
Posted: Thu Apr 24, 2008 2:25 pm Post subject:
|
|
|
Hi,
Try this method:
Start with the bleed nipple closed firmly, then get your helpful assistant to pump the brake pedal three times.
On the third stroke hold the pressure on the pedal and keep holding while you loosen the bleed nipple.
As the pedal hits the floor, quickly close the bleed nipple and only then allow the pedal to come back up with the nipple shut tight.
Thats the only way you will stop air entering back in through the bleed nipple.
Good luck!
Steve.
__________________________________ success is being able to go from one failure to another without losing enthusiasm
Land Rovers & Difflock - you can check-out any time you like, but you can never leave |
|
Back to top |
|
|
colint Gate Opener
Joined: 26 May 2002 Odometer: 34
|
Posted: Thu Apr 24, 2008 5:46 pm Post subject:
|
|
|
Damon - Yes that is what the official manual says to do. I have however tried it the way you suggested too. There are so many tiny bubbles in the fluid that I can see that the air is not being sucked back into the calliper on the up strokes. Thanks for the suggestion anyway though.
Steve - Thanks for the suggestion - I shall try that tomorrow after I've purchased some more fluid!
|
|
Back to top |
|
|
mmgemini Mud Obsessed
Joined: 26 Dec 2004 Odometer: 3096 Location: Stockton on Tees
|
Posted: Thu Apr 24, 2008 7:32 pm Post subject:
|
|
|
Go to Halfords.
Yes Halfords, buy yourself a Gunstons Ezi-Bleed.
Makes the job so simple for what the cost.
__________________________________ mike FOAK
Quis custodiet ipsos custodes
I can cause trouble in an empty house !!! |
|
Back to top |
|
|
Let Luce Mud Obsessed
Joined: 11 Dec 2002 Odometer: 4018 Location: Derbyshire
1977 Land Rover 101
|
Posted: Thu Apr 24, 2008 10:03 pm Post subject:
|
|
|
I once spent 3 days in a freezing Romanian carpark trying to sort the brakes on the 101, turned out to be a leaking blead nipple. Got so stressed with it being so cold, and kids pestering us all the time I couldn't see it. In the end we clamped off the rear brakes and drove to a campsite we'd seen signs to when we'd been into town on foot. Within an hour of being there the sun had come out and I'd found and fixed the problem.
__________________________________ Landrovers; a full time occupation
www.themorgans.info/expedition/index.php |
|
Back to top |
|
|
mudplugga Mud Obsessed
Joined: 23 Oct 2004 Odometer: 2798 Location: Shropshire mostly, and Mid Wales
|
Posted: Thu Apr 24, 2008 10:40 pm Post subject:
|
|
|
Quote: | I open the bleed nipple slightly - about 1 flat of the spanner. My helpful assistant then presses down quickly on the brake pedal, pauses, lets the pedal come up, pauses, then repeats. She continues this for some considerable time, until we stop to empty the jug, or top up the master cylinder. |
All you are doing is moving fluid backwards and forwards through the system.
Fill the master cylinder.
Attach your pipe and container to the first nipple when it is closed.
As your assistant slowly presses the pedal open the nipple, and then close it while the brake pedal is still down.
Let the brake pedal back up - with all nipples closed.
press the pedal, open the nipple, close the nipple and release the pedal.
Repeat until no bubbles of air can be seen coming through the pipe. Keep an eye on the master cylinder level as well.
Once you think the air has been bled from that wheel, do the same on the next wheel.
NEVER let the pedal return to the up position with a nipple open.
Or, go and buy a pressure bleeder like the Eezibleed.
__________________________________ http://www.ipernity.com/home/294337
"Roof, doors, wheels. It's the way I drive." |
|
Back to top |
|
|
Winnet Difflock Royalty
Joined: 03 Dec 2003 Odometer: 14725 Location: Aberdeen
1985 Land Rover
|
Posted: Thu Apr 24, 2008 10:50 pm Post subject:
|
|
|
And start at the furthest wheel from the master cylinder and work your way back to the wheel closest to the wheel cylinder.
G.
__________________________________ Bored......
All these questions and more after the tea break. |
|
Back to top |
|
|
brucel Just got MTs
Joined: 05 Sep 2006 Odometer: 151 Location: london
1990 Range Rover HSE
|
Posted: Fri Apr 25, 2008 8:27 am Post subject:
|
|
|
Everyone above is correct in their method. I'd check all connections and make sure there is no where air can get in. look for wet areas around joins.
One tip that has worked for me when I've had a awkard ******. Pump up the peddle keep all the nipples closed. Get a broom handle or whatever and keep (a lot of) pressure on the brake pedal and leave it overnight.
The theory is that air should make it's way up, with the master cylinder 'open' the bubble should float to the top and out the reservoir.
It worked for me with a disco just the other week.
Good luck
__________________________________ Bruce |
|
Back to top |
|
|
mmgemini Mud Obsessed
Joined: 26 Dec 2004 Odometer: 3096 Location: Stockton on Tees
|
Posted: Fri Apr 25, 2008 10:20 am Post subject:
|
|
|
You could have now ripped the seals in the brake master cylinder.
__________________________________ mike FOAK
Quis custodiet ipsos custodes
I can cause trouble in an empty house !!! |
|
Back to top |
|
|
|
Disco Sev Guest
|
Posted: Fri Apr 25, 2008 4:50 pm Post subject: Re: Air in the brake fluid - please help!
|
|
|
colint wrote: | I did try the eezebleed, but since I had no success at clearing the air out of the system, |
I'm sorry I don't have anything constructive to add but I'm amazed that two people have suggested that you buy an Eezi Bleed Doesn't anybody read posts properly
|
|
Back to top |
|
|
mmgemini Mud Obsessed
Joined: 26 Dec 2004 Odometer: 3096 Location: Stockton on Tees
|
Posted: Fri Apr 25, 2008 5:51 pm Post subject:
|
|
|
No Disco I can't........
Nor can I recomend pumping the pedal with modern master cylinders.
The only thing I can add is.
Is the fluid being kept to level in the Eezi -Bleed and is the correct master cylinder cap being used.
__________________________________ mike FOAK
Quis custodiet ipsos custodes
I can cause trouble in an empty house !!! |
|
Back to top |
|
|
colint Gate Opener
Joined: 26 May 2002 Odometer: 34
|
Posted: Fri Apr 25, 2008 6:38 pm Post subject:
|
|
|
Thanks everyone for your input.
climbing chris - It sounds like you had a bad few days - thanks for sharing that - After considering your story, I have taken a step back and looked at what I'm doing, and I still don't think that I've missed anything obvious.
Bruce - I like your theory - I'll try that too.
mmgemini - why do you think I may have ripped the seals in a new master cylinder by using it as it is designed to be used? Is there something I don't understand about how they work? I thought they were just pistons moving hydraulic fluid back and forth.
Dicso Sev - on the one hand: 'nuff said, on the other hand: I really am grateful for people taking the time and trouble to try to help me out.
Thanks again everyone - and any more new suggestions would be welcome too.
|
|
Back to top |
|
|
mmgemini Mud Obsessed
Joined: 26 Dec 2004 Odometer: 3096 Location: Stockton on Tees
|
Posted: Fri Apr 25, 2008 7:01 pm Post subject:
|
|
|
Colin. The name's mike.....
With use the modern master cylinders build a ridge across the bore of the cylinder where the seals stop at each application of the brake pedal.
When you bleed the system you take the brack master cylinder piston and seals past that ridge. That causes the seals to rip.
I've not had a problem bleeding with an Eezi-Bleed.
I keep an old wheel and tyre for that job. I'm also lucky enough to have an old Eezi-Bleed and I use the container to bleed the fluid into. That I hope stops any air getting in.
Drum braskes on the rear is there ?
Are they adjusted ? If so try knocking the adjusted back and bleeding that way.
Tandam master cylinder.
I bleed the furthest wheel cylinder away from the master cylinder that is the first one the piston in the master cylinder feeds. Do you understand that. Then the wheel cylinder feed by the same M/C piston.
Then I move to the wheel cylinders that the piston furthest away from the pedal feeds.
Do you understand that ?
By wheel cylinder I mean either calliper or wheel cylinder.
Hey lad. I haven't worked with drum brakes for over rwenty years......
__________________________________ mike FOAK
Quis custodiet ipsos custodes
I can cause trouble in an empty house !!! |
|
Back to top |
|
|
mmgemini Mud Obsessed
Joined: 26 Dec 2004 Odometer: 3096 Location: Stockton on Tees
|
Posted: Fri Apr 25, 2008 7:16 pm Post subject:
|
|
|
Colin.
I've re-read your original post again.
What happens to the brake pedal after you have bled the system.
In other words, what makes you think there's air in the system.......
Did you fit new front pads as well ?
I'll be back on in the morning
__________________________________ mike FOAK
Quis custodiet ipsos custodes
I can cause trouble in an empty house !!! |
|
Back to top |
|
|
Landy Andy Just got MTs
Joined: 04 Jan 2008 Odometer: 166 Location: Herts
|
Posted: Sun Apr 27, 2008 8:28 pm Post subject:
|
|
|
if you are pumping the pedal with out the engine running, the pedal will "pump up" as this is due to the servo.
I agree with most of the above. I personally dislike the ezi bleed systems, but understand their ease. Most important thing i note is never let pedal up when bleed is open.
I like/use the system of three pumps hold pressure open bleed, close bleed while holding pedal down, then three pumps etc.
Good luck Andy
|
|
Back to top |
|
|
waveydave Mud Obsessed
Joined: 10 Jan 2006 Odometer: 2740 Location: waveyvillie oop norf
1994 Land Rover Discovery
|
Posted: Sun Apr 27, 2008 10:22 pm Post subject:
|
|
|
colint I have been reading this post with some interest.
You say you have replcaed the rear shoes and cylinders. And you have used over 5 litres of fluid.
Theres a coman issue with replacing the shoes on older 10's as people often fit the shoes he wrong way round.
Its worth checking to see if you have fitted the shoes correctly as if you havnt you will have the symptoms you describe. IE you need a double pump of the pedal to get any brakes and it seams as if you have air in the system.
If you remove the rear drums and look at the shoes have a look and see if teh adjusters are any where near the pins on the shoes. Forgt any leading and trailing edge malarky that people (and haynes) tell you to look for. On the bakinging plate you will see the adjusters are differnt heights. The pins on the shoes must match these.
If you have fitted the shoes foloing the thraditonal leading and trailing edges on the shoes these pins will be in teh wrong places and you will never adjust them.
If the shoes are in correctly then you have an air leak. You should be able to bleed a completly dry system with less than half a litre. If all your joints are dry and all your pistons are dry and not leaking look again.
Maybee if it is air in the sustem your bleed nipples are letting in the air. Remove them clean them out and refit. Then dont undo them too far.
__________________________________ OUCH |
|
Back to top |
|
|
gsr341 Gate Opener
Joined: 06 Oct 2007 Odometer: 31 Location: north wales
|
Posted: Mon Apr 28, 2008 9:59 am Post subject:
|
|
|
i once had a problem with my series3 that i could not bleed all the air out of the brakes , turned out the flexable hose to the rear axel had a pin ***** in it didnt leak fluid out ? but sucked in air , only found it by chance as there was a clean spot on the hose !!
|
|
Back to top |
|
|
horsevad Gate Opener
Joined: 12 Sep 2004 Odometer: 22 Location: Try, Denmark
|
Posted: Mon Apr 28, 2008 7:47 pm Post subject: Re: Air in the brake fluid - please help!
|
|
|
colint wrote: | Hi
(...)
I open the bleed nipple slightly - about 1 flat of the spanner. My helpful assistant then presses down quickly on the brake pedal, pauses, lets the pedal come up, pauses, then repeats. She continues this for some considerable time, until we stop to empty the jug, or top up the master cylinder. When we stop, I ensure that I close the nipple whilst the pedal is down.
(...)
|
The above procedure is faulty.
You can pump the brake pedal in that fashin from here to eternity without ever bleeding the system.
Use this procedure:
Close nipple.
Push pedal down AND HOLD DOWN.
Open nipple by a small amount. Fluid with bubble will drip out.
The pedal can now be pressed fully down. HOLD THE PEDAL DOWN.
Tighten nipple.
Repeat as needed - usually three or four times pr wheel.
---
Providing constant pressure on the brake pedal - by jamming some stick between the pedal and the seat or otherwise - for prolonged periods may cause damage to the master cylinder. Futhermore - using this method will contaminate the brake fluid. Brake fluid can absorb small amounts of air and water - but this will weaken its chemical properties and thereby reducing the effectivenes of the brakes.
Bleed the system using above method. The system will be fully bled in under 15 minutes.
__________________________________ --------------------
'Ingenium res adversae nudare solent, celare secundae!' |
|
Back to top |
|
|
daft as a brush Gate Opener
Joined: 28 May 2007 Odometer: 9 Location: north kent
|
Posted: Mon Apr 28, 2008 8:11 pm Post subject:
|
|
|
hi this works on EVERYTHING fill oil tank at the top in this case brake fluid that has NOT been shaken up, loosen one any one it makes no difference and push a clear hose on the nipple take the other end of the hose to the oil tank and gently suck, on a dry system you watch the oil level drop on a used system watch the clear hose(as your well aware it doesn't taste to good but this is apparently the case with most fluids sucked out of pipes!) the idea is to prime the master Cly not the whole system,now gravity being what it is Will pull fluid down and air will flow out of the hose so put it in the oil tank and wait you can speed things up a lot by pumping the pedal but do this very slowly. the first inch or so of travel shuts the supply tank off after this your pumping fluid, if you do it fast air all ready in the system mixes with the fluid so slowly does it until the fluid is free from air and move to the next nipple, and like everyone else said check for leaks. and for those of you that dint be live i use this on hyd clutches and the air over hyd systems on mogs and tractors. all the best john
__________________________________ if at first you don't succeed use a bigger hammer |
|
Back to top |
|
|
|
Winnet Difflock Royalty
Joined: 03 Dec 2003 Odometer: 14725 Location: Aberdeen
1985 Land Rover
|
Posted: Mon Apr 28, 2008 8:37 pm Post subject:
|
|
|
daft as a brush wrote: | hi this works on EVERYTHING fill oil tank at the top in this case brake fluid that has NOT been shaken up, loosen one any one it makes no difference and push a clear hose on the nipple take the other end of the hose to the oil tank and gently suck, on a dry system you watch the oil level drop on a used system watch the clear hose(as your well aware it doesn't taste to good but this is apparently the case with most fluids sucked out of pipes!) the idea is to prime the master Cly not the whole system,now gravity being what it is Will pull fluid down and air will flow out of the hose so put it in the oil tank and wait you can speed things up a lot by pumping the pedal but do this very slowly. the first inch or so of travel shuts the supply tank off after this your pumping fluid, if you do it fast air all ready in the system mixes with the fluid so slowly does it until the fluid is free from air and move to the next nipple, and like everyone else said check for leaks. and for those of you that dint be live i use this on hyd clutches and the air over hyd systems on mogs and tractors. all the best john |
So you are basically creating a syphon, neat.
G.
__________________________________ Bored......
All these questions and more after the tea break. |
|
Back to top |
|
|
|