Hi Zeders
Since getting my Zed a few months ago, so far I've changed oil and coolant me self! Step by step instructions from Gazza and Mike F. thanks heaps.
I've searched the site for a 'how to' on changing brake fluid but to no avail....maybe I did not look in the right place. Is this a 'do it yourself' job for novice repairmen like myself or am I better off finding an Indie to do it?
cheers, soma
changing brake fluid
-
Justin Time
- Joined: Thu 22 Jun, 2006 20:34
- Posts: 2183
- Location: Kent
Mike Fishwick recommends using a Gunsons Auto Bleeder, I would imagine this piece of kit comes with instructions.
Gazza.
Gazza.
Gazza
"Understeer is when you hit the wall with the front of the car, oversteer is when you hit the wall with the rear of the car. Horsepower is how fast you hit the wall and torque is how far you take the wall with you"
Z3 S54 M roadster
, BMW Z1, BMW M3 CSL, Z4M Coupe
"Understeer is when you hit the wall with the front of the car, oversteer is when you hit the wall with the rear of the car. Horsepower is how fast you hit the wall and torque is how far you take the wall with you"
Z3 S54 M roadster
, BMW Z1, BMW M3 CSL, Z4M Coupegunsons
I found this link about using the Gunsons (AUD$59.00) with an amateur video clip attached but its fairly basic...no pun intended. the guy who made it says the instructions do not come with any diagram or illustrations::(
http://www.carbasics.co.uk/how_to_bleed_car_brakes.htm
This looks to be a step above the Gunsons and costs USD$49.00. Anyone have an opinion or experience with either of these?
http://www.eeuroparts.com/productdetail ... &code=6858#
http://www.carbasics.co.uk/how_to_bleed_car_brakes.htm
This looks to be a step above the Gunsons and costs USD$49.00. Anyone have an opinion or experience with either of these?
http://www.eeuroparts.com/productdetail ... &code=6858#
Well I can't say I've done mine myself, but the subject crops up on here from time to time. I did a quick search for "bleeder" on here and it turned up some useful looking threads.
I don't think it is such a pig of a job provided that you have the right tools, but as the $tealer I use only charged £34.18 (including both the fluid and VAT!) to do mine last time, I guess that is why most people don't bother - that and for me a lack of suitable place to work on the car.
Cheers R.
I don't think it is such a pig of a job provided that you have the right tools, but as the $tealer I use only charged £34.18 (including both the fluid and VAT!) to do mine last time, I guess that is why most people don't bother - that and for me a lack of suitable place to work on the car.
Cheers R.
Arctic Silver '99 Z3 1.9 & Black '59 Frogeye 1275cc
I changed my fluid a few months ago when I put new discs on. I bought a pressure bleed kit from Halfords and it was very easy. You just attach a cylinder on top of the brake fluid reservoir, fill it full of fluid and attach an airline to a tyre deflated to 20psi. Go round each brake caliper in turn and crack the bleed nipple and let the fluid run through. TIS says you should do it in the order RR, LR, RF, LF. You need to keep an eye on the fluid level and top it up when low.
There two very similar adapters in the Gunsons kit to connect the cylinder to the reservoir. Make sure to use the correct one, or it will blow off, as yours truly found
There two very similar adapters in the Gunsons kit to connect the cylinder to the reservoir. Make sure to use the correct one, or it will blow off, as yours truly found
Z3M with a few mods...and a little bit more power
The old fashioned way was to have a friend pump the brake pedal as you released the bleed nipple on the caliper/brake drum and collect the expelled fluid in a jar via a piece of rubber pipe, when the bubbles stopped the friend kept the pedal depressed until the bleed nipple was tightened. The friend topping up the reservoir as necessary, The order of bleeding was furthest wheel from the reservoir first.
Dont know if it is the same with Dual Circuit Systems.
Dont know if it is the same with Dual Circuit Systems.
Gazza
"Understeer is when you hit the wall with the front of the car, oversteer is when you hit the wall with the rear of the car. Horsepower is how fast you hit the wall and torque is how far you take the wall with you"
Z3 S54 M roadster, BMW Z1, BMW M3 CSL, Z4M Coupe
"Understeer is when you hit the wall with the front of the car, oversteer is when you hit the wall with the rear of the car. Horsepower is how fast you hit the wall and torque is how far you take the wall with you"
Z3 S54 M roadster
, BMW Z1, BMW M3 CSL, Z4M Coupe
garythefish, You are right, it may be the old way but providing a mate, wife etc can spend say 20 min with you it is easy, over the years I must have bled hundreds of brake systems on cars and trucks and only ever used a vacuum pump or bleeder a couple of times. The purpose of bleeding is to get rid of any air bubbles which would cause a spongy brake pedal. how ever unless you have done it before or have a friend that knows what to do I would suggest taking to a garage, brakes are quite an important bit on the car especially if you want to stop in a hurry. and be careful not to get any brake fluid near the paint work as it is an excellent stripper. I have not as yet done it on the Z and for what it should cost will let the dealer do it. 
, and took the paint down to primer.-
Guest
Dual circuits
It is virtually impossible to bleed dual-circuit brakes by the old 'pump and bleed' system, as the master cylinder has tandem master cylinders - one for each circuit.
This means that when the first circuit is free of air (the rear if you follow the procedure on the BMW TIS disc - not that it really matters) the lack of air will render this circuit incompressible, so making it impossible to move the pistons, and so preventing the second circuit from being bled properly.
That is why a pressure bleeder is such an essential piece of kit for working on modern cars, as it forces fluid through both cylinders while they are in their 'resting' position.
Many people have however tried to bleed dual-circuit systems by the old method, and although they think it has been accomplished satisfactorily, they were really braking on one and a half circuits.
If you feel competent to do this, buy a Gunsons pressure bleeder, a litre of fluid (you don't need 'Racing' type fluid - I use VW or ATE Dot 4 bought from German & Swedish) and small ring spanners which fit the nipples properly. Also buy some spare dust caps for the nipples, as one or two may be lost.
If the fluid has not been changed in living memory (ie if the car has a Full BMW Service History!) be prepared for some nipples not to bleed easily - they will be blocked by either mud from outside (missing caps) pr corrosion from within. In such cases, depressurise the system, remove the nipple, and clear it with stiff wire or a 2 mm drill bit until it can be blown through.
Do not use too much leverage when tightening the nipples - one finger at two inches will suffice.
While doing this job, remove the pads and make sure they can slide easily on their guide surfaces, which should be lightly coated on Copaslip.
This means that when the first circuit is free of air (the rear if you follow the procedure on the BMW TIS disc - not that it really matters) the lack of air will render this circuit incompressible, so making it impossible to move the pistons, and so preventing the second circuit from being bled properly.
That is why a pressure bleeder is such an essential piece of kit for working on modern cars, as it forces fluid through both cylinders while they are in their 'resting' position.
Many people have however tried to bleed dual-circuit systems by the old method, and although they think it has been accomplished satisfactorily, they were really braking on one and a half circuits.
If you feel competent to do this, buy a Gunsons pressure bleeder, a litre of fluid (you don't need 'Racing' type fluid - I use VW or ATE Dot 4 bought from German & Swedish) and small ring spanners which fit the nipples properly. Also buy some spare dust caps for the nipples, as one or two may be lost.
If the fluid has not been changed in living memory (ie if the car has a Full BMW Service History!) be prepared for some nipples not to bleed easily - they will be blocked by either mud from outside (missing caps) pr corrosion from within. In such cases, depressurise the system, remove the nipple, and clear it with stiff wire or a 2 mm drill bit until it can be blown through.
Do not use too much leverage when tightening the nipples - one finger at two inches will suffice.
While doing this job, remove the pads and make sure they can slide easily on their guide surfaces, which should be lightly coated on Copaslip.
Mike The method you are on about is a way to do it if you have the tackle available and no one to help and it is quick, I will not argue against it
however I know of owners that have done it the OLD way and they say they did not find any problems. As I said it is something that I have not done on my Z but for those that are interested check this out:
http://www.pelicanparts.com/BMW/techart ... Brakes.htm
It is a pretty basic job and is easy when you know how but if in doubt take it to the Dealers.
however I know of owners that have done it the OLD way and they say they did not find any problems. As I said it is something that I have not done on my Z but for those that are interested check this out:
http://www.pelicanparts.com/BMW/techart ... Brakes.htm
It is a pretty basic job and is easy when you know how
but if in doubt take it to the Dealers.-
Guest
Diy
Yes, I also know people who have bled dual circuit brakes the 'old' way - but I'm not at all convinced that they managed to fully bleed the second circuit they tackled.
Given that airless brake fluid is not compressible, how can you be sure that the small amount of piston travel remaining has expelled all the air? The brakes may FEEL firm, but that is due tothe first circuit having been bled fully, and so becoming incompressible.
It's easier anyway with a pressure bleeder, even on an old car with one circuit.
Given that airless brake fluid is not compressible, how can you be sure that the small amount of piston travel remaining has expelled all the air? The brakes may FEEL firm, but that is due tothe first circuit having been bled fully, and so becoming incompressible.
It's easier anyway with a pressure bleeder, even on an old car with one circuit.
Hi HowardZ. I will give you an honest answer before Mike climbs on his high horse... 
Brake fluid should not need "topping up", as it shouldn't be leaking from the system.
Brake fluid is however hygroscopic - that is, it absorbs water - and over time is needs changing - i.e. draining completely and refilling. When you do this you get air in the system and this needs to be purged, which is what this thread is mainly about - how to get the air out.
The clock symbol is just a timer and it is set to come on two years after it is reset as an indicator that it is time to change the brake fluid. A couple of months with the symbol on won't hurt, and most of us time it to coincide with a service, which is what I will be doing in a few weeks as mine is also on now.
Cheers R.
Brake fluid should not need "topping up", as it shouldn't be leaking from the system.
Brake fluid is however hygroscopic - that is, it absorbs water - and over time is needs changing - i.e. draining completely and refilling. When you do this you get air in the system and this needs to be purged, which is what this thread is mainly about - how to get the air out.
The clock symbol is just a timer and it is set to come on two years after it is reset as an indicator that it is time to change the brake fluid. A couple of months with the symbol on won't hurt, and most of us time it to coincide with a service, which is what I will be doing in a few weeks as mine is also on now.
Cheers R.
Arctic Silver '99 Z3 1.9 & Black '59 Frogeye 1275cc
If the brake fluid level looks low, dont be tempted to top it up as this is usually a good indication that the pads are more less worn down.
Similarly, if you're replacing the fluid, check the wear of the brake pads, because if they're low and you blled the fluid through and top the reservoir up to the top, when you come to chagne pads it will likely cause the fluid to overflow.
Similarly, if you're replacing the fluid, check the wear of the brake pads, because if they're low and you blled the fluid through and top the reservoir up to the top, when you come to chagne pads it will likely cause the fluid to overflow.
-
Guest
I bled my brakes the 'old fashioned' way when I changed to braided hoses and didn't find any issues. After the air was through I kept bleeding for a while more until fully clean fluid came through. I had my son do the pumping while I fiddled with the nipples. As long as you don't let the resovoir get too low or let air back in at the caliper, all will be well.
I hear what people say about dual-curcuit system, but that was not my experience. I would certainly never drain the system, just flush through with new fluid.
FWIW, it's not a fun job and as an indy will charge a very resonable rate. I am not sure its worth doing it yourself anyway.
I hear what people say about dual-curcuit system, but that was not my experience. I would certainly never drain the system, just flush through with new fluid.
FWIW, it's not a fun job and as an indy will charge a very resonable rate. I am not sure its worth doing it yourself anyway.
-
PhoenixCoupe
- Joined: Wed 02 May, 2007 00:46
- Posts: 739
- Location: Mars
