Bleeding Brakes
- Thread starter rholt
- Start date
andy watson
Moderator
Hi Gavin,
It is an original 944 option, bit like rocking horse poo I was really lucky to get this off eBay after a prompt from forum member on here after I had posted looking for one, it was still in packaging having never been fitted!
It is an original 944 option, bit like rocking horse poo I was really lucky to get this off eBay after a prompt from forum member on here after I had posted looking for one, it was still in packaging having never been fitted!
andy watson
Moderator
Simon - 944man
Heads up - dc performance have another Spax deal on at the moment RSX118 kit £626-57 delivered, if you were still interested?
Heads up - dc performance have another Spax deal on at the moment RSX118 kit £626-57 delivered, if you were still interested?
andy watson
Moderator
ORIGINAL: 944 man
Only just noticed this Andy.
I refer the honourable gentlemen to my post dated February the first... []
Doh!! [
]Hadn't seen that, I am not on commission promise [
][]
The only thing to add to what has already been said is that if you bleed the brakes, they can still feel a bit spongy. If you re-bleed them the following day you find there is yet a small amount of air to come out of each bleed nipple.
My guess is that small bubbles can sometimes catch on the sides of the calipers and take some time to float to the top. Thumping the calipers with a rubber mallet while doing the job can help to dislodge them (a bit more than the 'gentle tap' as espoused by Mr Graham!), but it's not 100%.
Oli.
My guess is that small bubbles can sometimes catch on the sides of the calipers and take some time to float to the top. Thumping the calipers with a rubber mallet while doing the job can help to dislodge them (a bit more than the 'gentle tap' as espoused by Mr Graham!), but it's not 100%.
Oli.
924nutter
PCGB Member
The best time to bleed brake is when new pads have been fitted although this is not always convenient. It pushes the pistons back into the caliper so reducing the void in which the bubbles can stay trapped. I suppose taking this to its logical conclusion you could insert wooden wedges to hold the pistons right in but then again, a good bleeding aid like the Gunsons eezibleed probably renders that suggestion overkill. I like the idea of giving them another go the day after like Oli says, because although the brakes bite on my cab they do feel spongy, after having the plate lift sorted, (I know shame on me for paying an indie, but I dont have a mig welder to tack a nut on the head of the bolt) , but a bit tough on the wallet if you are getting your indie, or indeed a Porsche centre to do it
924nutter
PCGB Member
Quite so, and I use it to replace the oil in the gear box on the AX GTI as well the give it a thorought wash in soapy water then meths then dry it so as not to contaminate the brake fluid next time. Always use brand new freshly opened fuid and not from that old tin knocking about at the back of the shed, because however hard you try it will absorb moisture and do not use bleed-off to top up the master-cylinder as it will contain bubbles
I speak from experience.
(If you are using the spare tyre method - make sure you have got enough pressure in it beforehand and then lower it to the pressure limit recommended with the kit).
Use AP660 fluid.
Do not drain the fluid totally - not always a problem - but it does introduce air into the system.
Remember - each corner may have TWO bleed nipples. Doesn't really matter which order you bleed these - I start with the outer one each time.
Use a ring spanner on the bleed nipples - don't be tempted to use 'Ein Englander'.
Start at the rear right-hand side, then rear left, then front right and finally front left. i.e. Start with the furthest away from the reservoir.
As you bleed each nipple you will get air bubbles coming out into your jar. Continue for a while as you will not see the smallest air-bubbles.
Try not to let the fluid level drop below minimum level in the reservoir. Top up as necessary - after releasing the pressure. You're likely to use at least a litre for a full system bleed - perhaps 2 litres. Get plenty of back-up supplies - a lot easier than trying to find the fluid you want on a Sunday at 4pm.
You may have to repeat the cycle a few times to get a hard pedal.
(If you are using the spare tyre method - make sure you have got enough pressure in it beforehand and then lower it to the pressure limit recommended with the kit).
Use AP660 fluid.
Do not drain the fluid totally - not always a problem - but it does introduce air into the system.
Remember - each corner may have TWO bleed nipples. Doesn't really matter which order you bleed these - I start with the outer one each time.
Use a ring spanner on the bleed nipples - don't be tempted to use 'Ein Englander'.
Start at the rear right-hand side, then rear left, then front right and finally front left. i.e. Start with the furthest away from the reservoir.
As you bleed each nipple you will get air bubbles coming out into your jar. Continue for a while as you will not see the smallest air-bubbles.
Try not to let the fluid level drop below minimum level in the reservoir. Top up as necessary - after releasing the pressure. You're likely to use at least a litre for a full system bleed - perhaps 2 litres. Get plenty of back-up supplies - a lot easier than trying to find the fluid you want on a Sunday at 4pm.
You may have to repeat the cycle a few times to get a hard pedal.
andy watson
Moderator
Lifting the front of the car aids the natural venting of air too
If the system is empty and you are doing all 4 brakes then have the car level if its just the rear then lift the front a bit. It doesn't have to be pointing at the stars just up a bit. Then what I do is open all the bleed nipples that you are going to bleed.Then fill the reservoir and wait till you get fluid coming out of the bleed nipples. ( don't worry it will not run out at a tremendous rate more of a dribble. Then close the nipples and bleed one at a time starting with the caliper that is furthest away from the master cylinder.This way you will have fluid in the pipes before you start.
Monkeythree
New member
System is (was) empty and the car is level on 4 axle stands. Bit tricky to start tilting it now. I had started with the right rear because conventional wisdom says furthest from the MC first but i got fed up after 20 minutes of getting only the merest dribble of fluid through to the back and switched to the fronts instead. Front right has now bled pretty well but front left is still very bubbly. My current thinking is to try to get the fronts full of fluid and then with less air in the overall system, the rears might eventually bleed through.
I'm not convinced by the vacuum pump method because i don't believe the threads on the bleed nipples are airtight so as soon as the nipple is open, the vacuum pump must draw some air down the threads, thus reducing the vacuum effect on the brake line. That's my theory anyway.
As luck would have it, I've managed to find a Gunsons Eazi Bleed in the archives this evening and amazingly I even have a cap which fits the S2 MC reservoir so I'm going to have go with that tomorrow. Mrs M3 is working from home tomorrow so I will recruit her as pedal pusher and hopefully the combination of the Eazi bleed and forced manual labour will do the trick.
I'm not convinced by the vacuum pump method because i don't believe the threads on the bleed nipples are airtight so as soon as the nipple is open, the vacuum pump must draw some air down the threads, thus reducing the vacuum effect on the brake line. That's my theory anyway.
As luck would have it, I've managed to find a Gunsons Eazi Bleed in the archives this evening and amazingly I even have a cap which fits the S2 MC reservoir so I'm going to have go with that tomorrow. Mrs M3 is working from home tomorrow so I will recruit her as pedal pusher and hopefully the combination of the Eazi bleed and forced manual labour will do the trick.
Sounds like the master cylinder needs priming or you may be drawing air into the system. Have you checked all your new connections?
If you're having trouble getting fluid to each corner, disconnect at the calliper, push fluid through the line then reconnect. Do this for each corner, then try bleeding as normal.
Some systems can be real pig when fully evacuated. I remember having one system where it was necessary to remove and hold the calliper during bleeding so the bleed nipple was upright in order to expel all the air.
If your still having trouble, it could be a faulty master cylinder.
Regards,
Clive.
If you're having trouble getting fluid to each corner, disconnect at the calliper, push fluid through the line then reconnect. Do this for each corner, then try bleeding as normal.
Some systems can be real pig when fully evacuated. I remember having one system where it was necessary to remove and hold the calliper during bleeding so the bleed nipple was upright in order to expel all the air.
If your still having trouble, it could be a faulty master cylinder.
Regards,
Clive.
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