Replacing brake fluid
Replacing brake fluid
Are there any tips on replacing brake fluid or do I just open all the nipples and pump the pedal until the reservoir is empty?
Standard RS4 (is it the only standard one left?)
Re: Replacing brake fluid
My advice would be to go to Halfords and buy a Gunson easibleed.
The easibleed is about a tenner if I recall corectly, and buy one of their decent brake nipple spanners while you are at it. If you round a nipple off (ooh err !) or worse, break one, it can all get very messy.
It is a bottle with a pair of pipes on it.
You fill the bottle half way with fluid, attach the correct cap to suit your reservoir, screw it on, and attach the other one to a tyre valve which puts the fluid under pressure.
Now all you need to do is bleed from each brake fluid valve in turn starting with the furthest. You do this by fitting a small piece of clear pipe to the nipple, poke its other end in a clear bottle (milk bottle etc) open the valve and let fluid out until it runs like fresh fluid. Then tighten it up and move on to the next one.
Remember to keep an eye on the fluid bottle up front though, to make sure it doesn't run out !
This saves having to pump the pedal as the pressure does it for you.
There is supposedly some magic needed to get the ABS pump to bleed correctly, but this method does most of the system.
HTH.
Cheers,
John.
The easibleed is about a tenner if I recall corectly, and buy one of their decent brake nipple spanners while you are at it. If you round a nipple off (ooh err !) or worse, break one, it can all get very messy.
It is a bottle with a pair of pipes on it.
You fill the bottle half way with fluid, attach the correct cap to suit your reservoir, screw it on, and attach the other one to a tyre valve which puts the fluid under pressure.
Now all you need to do is bleed from each brake fluid valve in turn starting with the furthest. You do this by fitting a small piece of clear pipe to the nipple, poke its other end in a clear bottle (milk bottle etc) open the valve and let fluid out until it runs like fresh fluid. Then tighten it up and move on to the next one.
Remember to keep an eye on the fluid bottle up front though, to make sure it doesn't run out !
This saves having to pump the pedal as the pressure does it for you.
There is supposedly some magic needed to get the ABS pump to bleed correctly, but this method does most of the system.
HTH.
Cheers,
John.
Too many toys, not enough time
Re: Replacing brake fluid
I agree with John, ive used the gunsons ezee bleed and it works great. Just make sure ur tyre pressure isnt more than 20psi or it wont work properly.
My DVD System
Re: Replacing brake fluid
There is supposedly some magic needed to get the ABS pump to bleed correctly, but this method does most of the system.
Here is a link to the aforementioned magic !
p.s. you need a VAG-COM !
[img]images/graemlins/thumbs.gif[/img]
https://www.speedcams.co.uk
B5 2.7t S4 - gone
B5 2.7t RS4 - gone
Ed 30 Golf DSG - gone
A5 3.0tdi - gone within 12 months!
S3 2.0 tfsi - 6+ years, but now sold
2018 Golf R 7.5
B5 2.7t S4 - gone
B5 2.7t RS4 - gone
Ed 30 Golf DSG - gone
A5 3.0tdi - gone within 12 months!
S3 2.0 tfsi - 6+ years, but now sold
2018 Golf R 7.5
Re: Replacing brake fluid
Thanks for the info.
As I don't have VAG-COM does this mean I can't do it successfully. Or can I just run the engine while bleeding?
Perhaps a trip to the dealer.
As I don't have VAG-COM does this mean I can't do it successfully. Or can I just run the engine while bleeding?
Perhaps a trip to the dealer.
Standard RS4 (is it the only standard one left?)
Re: Replacing brake fluid
You can still bleed them, just means that the fluid in the abs pump may not get swapped.
IMO the fluid in the calipers is usually the most important to swap anyway, as this get most of the heating/cooling.
IMO the fluid in the calipers is usually the most important to swap anyway, as this get most of the heating/cooling.
Too many toys, not enough time
Re: Replacing brake fluid
In order to renew the brake fluid, just bleeding the calipers won't be sufficient, so you will need to activate the ABS pump in order to ensure that you replace the fluid/and air within. My local specialist does it by running the engine - does anyone know if this is sufficient ?
Nige.
Nige.
https://www.speedcams.co.uk
B5 2.7t S4 - gone
B5 2.7t RS4 - gone
Ed 30 Golf DSG - gone
A5 3.0tdi - gone within 12 months!
S3 2.0 tfsi - 6+ years, but now sold
2018 Golf R 7.5
B5 2.7t S4 - gone
B5 2.7t RS4 - gone
Ed 30 Golf DSG - gone
A5 3.0tdi - gone within 12 months!
S3 2.0 tfsi - 6+ years, but now sold
2018 Golf R 7.5
Re: Replacing brake fluid
No it isn't, and this was my point...
Having the ignition on means the pump builds pressure ready for use, but does not result in the fluid in the ABS pump/actuator being flushed.
Replacing the fluid in the master cylinder, pipework, and calipers is a good start. Not replacing the fluid in the ABS bits just means the new fluid gets slightly contaminated, and consequently just needs replacing a bit sooner than it would have done.
VAG recommend fluid changes every 2/3 years, but this is with 'normal' driving. If you do track days then it is worth giving them a bleed after every other one, or sooner if you get a soft pedal.
This is all based on my own experiences, and has worked fine for me so far [img]images/graemlins/tongue.gif[/img]
Having the ignition on means the pump builds pressure ready for use, but does not result in the fluid in the ABS pump/actuator being flushed.
Replacing the fluid in the master cylinder, pipework, and calipers is a good start. Not replacing the fluid in the ABS bits just means the new fluid gets slightly contaminated, and consequently just needs replacing a bit sooner than it would have done.
VAG recommend fluid changes every 2/3 years, but this is with 'normal' driving. If you do track days then it is worth giving them a bleed after every other one, or sooner if you get a soft pedal.
This is all based on my own experiences, and has worked fine for me so far [img]images/graemlins/tongue.gif[/img]
Too many toys, not enough time
Re: Replacing brake fluid
Article copied from STOP TECH's website
http://stoptech.com/whitepapers/bleeding_abs_122701.htm
April 22, 2001
In general, whenever you are bleeding an ABS-equipped vehicle you can do so exactly as you would any other vehicle - stroke the pedal to pressurize the system, open a bleeder, close the same bleeder, and repeat. This does not change whether you are pressure-bleeding, vacuum-bleeding, or manual-bleeding. Just follow the same steps you normally would for a non-ABS vehicle and you're most of the way there.
Operative Word: Most
Now, with some ABS devices, you are actually done no matter what (Delphi's early ABS VI, for example). Bleed as above, and you are finished. Note that there are some special situations where the retailer will perform a diagnostic bleed of these early ABS units, but this is not within the scope of this article. Stop reading, and go get a drink.
However, other ABS devices have their own internal reservoirs (Bosch ABS5.3, for example) that are not a part of the primary brake circuit and are only opened to the rest of the circuit when the ABS is active. Now, if you just bled your system per the above technique and never again cycled your ABS, you would be fine. However, as soon as the ABS cycled - even for a few tenths of a second - the "old" fluid (which was never bled because it was hidden) would be dumped into the primary circuit. Not the end of the world, but you want fresh fluid everywhere, right?
The Factory Procedure
With these systems, the correct way to bleed the ENTIRE vehicle is to employ a Dealer service tool (it usually looks like a Nintendo GameBoy) that allows you to cycle the ABS valves and/or the pump motor WHILE you are bleeding the brakes. In effect, this allows you to open the hidden passages in order to purge the fluid completely. Fresh fluid is then drawn into the ABS unit, and the old stuff can be flushed away with the rest of the mess. Nothing to it.
The end result takes a little more time than a conventional bleed, and requires you use a little more fluid, but looks like this:
Step 1 - Manually bleed RR, LR, RF, LF brakes
Step 2 - Install service tool and cycle all valves and/or pumps
Step 3 - Manually bleed RR, LR, RF, and LF brakes again
You end up having bled the system twice, but this is necessary to ensure that fresh fluid - and NOT used fluid - is drawn into the unit the next time that the ABS valves (and/or pump) are cycled.
The 75% Answer
The last 25% of course is "does my car have these mysterious hidden passages?" That's for you to find out, but the following information should be useful in your quest for ABS knowledge.
As with any technology, manufacturers have produced several types of ABS over the years, and listing them all is simply not possible. In general, the most recent ABS product offerings - Bosch ABS5.7, Bosch ABS5.3, Delphi's DBC7 - all DO have the hidden passages and would require the procedure listed above. However, you cannot always rely on this generalization alone.
Our advice? Make a phone call to your local service department asking what their procedure is to bleed the brakes WHEN A NEW ABS UNIT IS INSTALLED (as opposed to when they change a caliper). If they claim that they need to cycle the ABS, it's a good bet that you need to also.
But What If I Don't Have The Dealer Service Tool?
If you really feel the need to cycle the valves, but do not have access to a service tool (or if the dealer is not willing to loan theirs) you COULD just replace Step #2 above with "go driving and slam on the brakes a few times to make the ABS work" to purge the used fluid from the unit. This is usually NOT the most efficient nor socially responsible solution, though it seems to work just fine. You still need to bleed the car a second time, but it saves you from procuring the service tool.
But what about when I'm at the track?
Remember that this is the process for FLUSHING AND FILLING YOUR ENTIRE SYSTEM. If you are only replacing a caliper or performing any other operation where you are simply trying to bleed vapor and/or used fluid from the wheel-end components (like after a hard day of lapping,) you need only to bleed the brakes as you normally would...ala Step #1 above.
There is no reason to cycle the ABS if all you are simply trying to do is get vapor out of the calipers. For this reason, if you flush and fill your system only once per year, the rest of the time you will not need to perform the ABS cycling procedure…or worry about the service tool at all.
http://stoptech.com/whitepapers/bleeding_abs_122701.htm
April 22, 2001
In general, whenever you are bleeding an ABS-equipped vehicle you can do so exactly as you would any other vehicle - stroke the pedal to pressurize the system, open a bleeder, close the same bleeder, and repeat. This does not change whether you are pressure-bleeding, vacuum-bleeding, or manual-bleeding. Just follow the same steps you normally would for a non-ABS vehicle and you're most of the way there.
Operative Word: Most
Now, with some ABS devices, you are actually done no matter what (Delphi's early ABS VI, for example). Bleed as above, and you are finished. Note that there are some special situations where the retailer will perform a diagnostic bleed of these early ABS units, but this is not within the scope of this article. Stop reading, and go get a drink.
However, other ABS devices have their own internal reservoirs (Bosch ABS5.3, for example) that are not a part of the primary brake circuit and are only opened to the rest of the circuit when the ABS is active. Now, if you just bled your system per the above technique and never again cycled your ABS, you would be fine. However, as soon as the ABS cycled - even for a few tenths of a second - the "old" fluid (which was never bled because it was hidden) would be dumped into the primary circuit. Not the end of the world, but you want fresh fluid everywhere, right?
The Factory Procedure
With these systems, the correct way to bleed the ENTIRE vehicle is to employ a Dealer service tool (it usually looks like a Nintendo GameBoy) that allows you to cycle the ABS valves and/or the pump motor WHILE you are bleeding the brakes. In effect, this allows you to open the hidden passages in order to purge the fluid completely. Fresh fluid is then drawn into the ABS unit, and the old stuff can be flushed away with the rest of the mess. Nothing to it.
The end result takes a little more time than a conventional bleed, and requires you use a little more fluid, but looks like this:
Step 1 - Manually bleed RR, LR, RF, LF brakes
Step 2 - Install service tool and cycle all valves and/or pumps
Step 3 - Manually bleed RR, LR, RF, and LF brakes again
You end up having bled the system twice, but this is necessary to ensure that fresh fluid - and NOT used fluid - is drawn into the unit the next time that the ABS valves (and/or pump) are cycled.
The 75% Answer
The last 25% of course is "does my car have these mysterious hidden passages?" That's for you to find out, but the following information should be useful in your quest for ABS knowledge.
As with any technology, manufacturers have produced several types of ABS over the years, and listing them all is simply not possible. In general, the most recent ABS product offerings - Bosch ABS5.7, Bosch ABS5.3, Delphi's DBC7 - all DO have the hidden passages and would require the procedure listed above. However, you cannot always rely on this generalization alone.
Our advice? Make a phone call to your local service department asking what their procedure is to bleed the brakes WHEN A NEW ABS UNIT IS INSTALLED (as opposed to when they change a caliper). If they claim that they need to cycle the ABS, it's a good bet that you need to also.
But What If I Don't Have The Dealer Service Tool?
If you really feel the need to cycle the valves, but do not have access to a service tool (or if the dealer is not willing to loan theirs) you COULD just replace Step #2 above with "go driving and slam on the brakes a few times to make the ABS work" to purge the used fluid from the unit. This is usually NOT the most efficient nor socially responsible solution, though it seems to work just fine. You still need to bleed the car a second time, but it saves you from procuring the service tool.
But what about when I'm at the track?
Remember that this is the process for FLUSHING AND FILLING YOUR ENTIRE SYSTEM. If you are only replacing a caliper or performing any other operation where you are simply trying to bleed vapor and/or used fluid from the wheel-end components (like after a hard day of lapping,) you need only to bleed the brakes as you normally would...ala Step #1 above.
There is no reason to cycle the ABS if all you are simply trying to do is get vapor out of the calipers. For this reason, if you flush and fill your system only once per year, the rest of the time you will not need to perform the ABS cycling procedure…or worry about the service tool at all.
Re: Replacing brake fluid
For what it's worth.....Details straight out of the Audi Erwin 'Maintenance' manual
Brake fluid change every 24months Only use new genuine VW/Audi brake fluid to US standard FMVSS 116 DOT4 (£5 for a litre from my local Audi)
One of the notes:
"Brake fluid is hygroscopic, ie. it absorbs moisture from the surrounding atmsophere. It is thus always to be kept in containers with an air tight seal."
My rule is don't use fuid that has been opened for any length of time. For all it costs.
Special VW tools quoted:
Brake filling and bleeding unit VAG 1238B or 1869. - what ever that is??
The following procedure is when using the above tool.
Open the bleed screw on the rear right caliper.
With suitable container bla bla..
With engine running, use the brake pedal to pump out fluid until the fluid level reaches the 'connection arrow' on the resevoir. (A figure highlights an apparent standard looking hose connection point on the bottom of the fluid resevior. looks similar to bleed type nipple connection. Can't say I noticed that on mine, but I wasn't looking. I simply flushed as I would any other car.)
Close bleed screw.
On vehicles with manual gearbox the clutch slave cyclinder should also be flushed with new brake fluid. When doing so note the following:
Connect VAG 1238 B or VAG 1869 but do not switch engine on.
Open bleed screw on clutch slave cylinder
Switch on the bleeder appliance and allow about 100cm3 of brake fluid to drain.
Close bleed screw
Sequence for changing brake fluid in brake calipers:
1. Rear right brake caliper
2. Rear left brake caliper
3. Front right brake caliper
4. Front left brake caliper
Connect breather hose of brake fluid collector and bleed screw on relevant caliper.
Open bleed screw and allow abour 200cm3 of brake fluid to darin out.
Pumping in new brake fluid flushes flushes the used brake fluid out of the system.
Close bleed screw
Disconnect hose from brake fluid reservoir. (I assume this is the connection arrow mention above)
Check pedal pressure brake pedal free play.
- Free play: max 1/3 of pedal travel!!
-During the final test drive, ensure that the ABS controlled brake application is carried out at least once with noticeable pulsing of the brake pedal.
END
Brake fluid change every 24months Only use new genuine VW/Audi brake fluid to US standard FMVSS 116 DOT4 (£5 for a litre from my local Audi)
One of the notes:
"Brake fluid is hygroscopic, ie. it absorbs moisture from the surrounding atmsophere. It is thus always to be kept in containers with an air tight seal."
My rule is don't use fuid that has been opened for any length of time. For all it costs.
Special VW tools quoted:
Brake filling and bleeding unit VAG 1238B or 1869. - what ever that is??
The following procedure is when using the above tool.
Open the bleed screw on the rear right caliper.
With suitable container bla bla..
With engine running, use the brake pedal to pump out fluid until the fluid level reaches the 'connection arrow' on the resevoir. (A figure highlights an apparent standard looking hose connection point on the bottom of the fluid resevior. looks similar to bleed type nipple connection. Can't say I noticed that on mine, but I wasn't looking. I simply flushed as I would any other car.)
Close bleed screw.
On vehicles with manual gearbox the clutch slave cyclinder should also be flushed with new brake fluid. When doing so note the following:
Connect VAG 1238 B or VAG 1869 but do not switch engine on.
Open bleed screw on clutch slave cylinder
Switch on the bleeder appliance and allow about 100cm3 of brake fluid to drain.
Close bleed screw
Sequence for changing brake fluid in brake calipers:
1. Rear right brake caliper
2. Rear left brake caliper
3. Front right brake caliper
4. Front left brake caliper
Connect breather hose of brake fluid collector and bleed screw on relevant caliper.
Open bleed screw and allow abour 200cm3 of brake fluid to darin out.
Pumping in new brake fluid flushes flushes the used brake fluid out of the system.
Close bleed screw
Disconnect hose from brake fluid reservoir. (I assume this is the connection arrow mention above)
Check pedal pressure brake pedal free play.
- Free play: max 1/3 of pedal travel!!
-During the final test drive, ensure that the ABS controlled brake application is carried out at least once with noticeable pulsing of the brake pedal.
END
Re: Replacing brake fluid
I should have stated that the above procedure is taken form the official Ewin Audi manual for A4s 1995> B5 chassis covers S4/RS4.
Re: Replacing brake fluid
Another good article: from
http://www.brickboard.com/ARCHIVES/1998 ... 0870.shtml Basically did a Googgle.com search
Interesting point about not pumping the pedal to floor with a potentially worn master cyclinder.
Point to note you can get service kits for master cylinders i.e. seals etc. No need to go the expensive route as most dealers would have you do. This is the same for calipers. Twice dealers have tried to get hundreds out of me for sticking calipers and faulty master cylinders.
Mazda wanted £500 to replace one front caliper! In the rush I special ordered an new caliper from a motor factor for £90 without checking the old caliper, only to find all it needed was new seals for £5! [img]images/graemlins/jawdrop.gif[/img] It was the same Girling unit that Mazda wanted £250 for! [img]images/graemlins/rocketwhore.gif[/img]
Anyway here's the article: [img]images/graemlins/yellows4.gif[/img]
"When you open your brake system, there is a good chance that you will get air in the lines to other calipers that you have not opened up, so you must bleed the entire system.
If you use the pedal to bleed the brakes, you must be careful not to push the pedal all the way to the floor. In normal use, the pedal never goes all the way to the floor, and hence, the piston in the master cylinder never travels all the way to the end. In that unused portion, crud and corrosion usuallyl build up, and if you hit that area while bleeding, it is likeliy that you will ruin the seals on the master cylinder and shortly require a new one.
As other have noted, the Eezibleed is the way to go - pressure bleeding is much better for the system and does a better job, however, with new calipers, you WILL need a heavy plastic mallet to rap the new calipers while bleeding and knock loose air bubbles that adhere to the new bores.
Be sure to use the correct bleeding sequence. I believe that Ted gave you the sequence for cars with ABS brakes. If you do not have ABS and have the 'dual triangular' system, then the sequence is slightly different:
LR
LF (Upper) (Inner, then outer)
RF (Upper) (Inner, then outer)
RR
RF (Lower)
LF (Lower)
I usually bleed all untill clean fluid comes out, then bleed all a second time. Rap on new calipers each time.
If you have trouble getting flow from any caliper, release pressure from bleeder, remove bleed screw and carefully clean bleeder and caliper hole with fine wire.
If you have trouble with flow at rear calipers, have assistant pump pedal halfway while pressure bleeder is in place - sometimes the rear pressure relief valves (sort of an early rear wheel anti-lock device) collect a lot of crud if system had not been flushed regularly and it can block fluid flow.
If this does not return good pedal, then check all brake hoses for signs of age - they could be 'balooning'. Also, it is possible that your master cylinder is failing. Note that with new pads, particularly with old rotors that have not been machined, or if you have used one of the rubbery anti-squeal substances on the back of the pads, there may be some 'give' in the pedal that will feel a bit like a soft pedal. Normally this will go away after the pads have worn in to match the rotor surface and you do a couple of good hard brake applications.
It is good practice to allow the pads to wear in gently for a hundred miles or so - no heavy applications. Then, do several 60 - 0 hard stops to heat the pads up to the point that you can smell them. This drives out the solvents used during manufacturing and will help prevent future glazing of the pads - they will work better during their life. --"
http://www.brickboard.com/ARCHIVES/1998 ... 0870.shtml Basically did a Googgle.com search
Interesting point about not pumping the pedal to floor with a potentially worn master cyclinder.
Point to note you can get service kits for master cylinders i.e. seals etc. No need to go the expensive route as most dealers would have you do. This is the same for calipers. Twice dealers have tried to get hundreds out of me for sticking calipers and faulty master cylinders.
Mazda wanted £500 to replace one front caliper! In the rush I special ordered an new caliper from a motor factor for £90 without checking the old caliper, only to find all it needed was new seals for £5! [img]images/graemlins/jawdrop.gif[/img] It was the same Girling unit that Mazda wanted £250 for! [img]images/graemlins/rocketwhore.gif[/img]
Anyway here's the article: [img]images/graemlins/yellows4.gif[/img]
"When you open your brake system, there is a good chance that you will get air in the lines to other calipers that you have not opened up, so you must bleed the entire system.
If you use the pedal to bleed the brakes, you must be careful not to push the pedal all the way to the floor. In normal use, the pedal never goes all the way to the floor, and hence, the piston in the master cylinder never travels all the way to the end. In that unused portion, crud and corrosion usuallyl build up, and if you hit that area while bleeding, it is likeliy that you will ruin the seals on the master cylinder and shortly require a new one.
As other have noted, the Eezibleed is the way to go - pressure bleeding is much better for the system and does a better job, however, with new calipers, you WILL need a heavy plastic mallet to rap the new calipers while bleeding and knock loose air bubbles that adhere to the new bores.
Be sure to use the correct bleeding sequence. I believe that Ted gave you the sequence for cars with ABS brakes. If you do not have ABS and have the 'dual triangular' system, then the sequence is slightly different:
LR
LF (Upper) (Inner, then outer)
RF (Upper) (Inner, then outer)
RR
RF (Lower)
LF (Lower)
I usually bleed all untill clean fluid comes out, then bleed all a second time. Rap on new calipers each time.
If you have trouble getting flow from any caliper, release pressure from bleeder, remove bleed screw and carefully clean bleeder and caliper hole with fine wire.
If you have trouble with flow at rear calipers, have assistant pump pedal halfway while pressure bleeder is in place - sometimes the rear pressure relief valves (sort of an early rear wheel anti-lock device) collect a lot of crud if system had not been flushed regularly and it can block fluid flow.
If this does not return good pedal, then check all brake hoses for signs of age - they could be 'balooning'. Also, it is possible that your master cylinder is failing. Note that with new pads, particularly with old rotors that have not been machined, or if you have used one of the rubbery anti-squeal substances on the back of the pads, there may be some 'give' in the pedal that will feel a bit like a soft pedal. Normally this will go away after the pads have worn in to match the rotor surface and you do a couple of good hard brake applications.
It is good practice to allow the pads to wear in gently for a hundred miles or so - no heavy applications. Then, do several 60 - 0 hard stops to heat the pads up to the point that you can smell them. This drives out the solvents used during manufacturing and will help prevent future glazing of the pads - they will work better during their life. --"
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