Bleeding the servo

[Slipperyeel]

I'm about to flush/bleed the servo on my GSA (05). Each time i do this i find myself searching YouTube and elsewhere for the correct order and the correct nipples (there's a veritable forest of them in there). I end up watching some video in Cech as i find nowt else.

It's there a good crib somewhere for the correct nipples (front vs rear) on top of the servo and does it really matter which order?

Thanks for any tips


sent from my phone, so probably lots of typos!

 

[Ian J Hartley]

I'm about to flush/bleed the servo on my GSA (05). Each time i do this i find myself searching YouTube and elsewhere for the correct order and the correct nipples (there's a veritable forest of them in there). I end up watching some video in Cech as i find nowt else.

It's there a good crib somewhere for the correct nipples (front vs rear) on top of the servo and does it really matter which order?

Thanks for any tips


sent from my phone, so probably lots of typos!

I'm sure this has been discussed before. I know a while ago I read a reference to a BMW servicing bulletin that stated there was no requirement to bleed each of the 3 nipples, and that just bleeding one was all that was required. The trouble is I can't remember which of the 3 the bulletin referred too. My guess is that if the highest bleed point is used (air rises in a liquid) then that should do the trick.

Ian

 

[DrFarkoff]

Its not Bleeding that is needed

Its "FLUSHING"

That's why you need to open all the nipples in correct sequences as there are small spaces that won;t be properly flushed with fresh fluid without doing so

I tried both ways I did it at just the last nipple and flushed till it ran clean and then I checked with the nipples in sequence and got a couple of teaspoons of dirty fluid out

http://advwisdom.hogranch.com/Wisdom/service_abs3.pdf

This is the one that I tested my theory on, I had it in for a service a few years ago R1150RT 65.000miles no recorded fluid changes!

Thats about 400 ml in the big jar and the fluid had gone clear in the tube as I stopped pumping / flushing

Do you see the last remnants in the 250ml reservoir that's from doing the flush in sequence maybe 2 or 3 teaspoons

Spend the Time Doing it Right! it will likely last quite a bit longer than leaving the dirty stuff in there to attack seals and clearances and polluting the fresh stuff from the start

 

[Slipperyeel]

Thanks Ian. I'll do a search on the bulletins from bmw.

To be honest i should watch that Cech video and write it down! I think I'll do that and post it here, just in case anyone wants to do all 3. but doing just one is much more appealing because that area around all those nipples ends up needing a good clean after doing them all!

Thanks


sent from my phone, so probably lots of typos!

 

[Ian J Hartley]

Thanks Ian. I'll do a search on the bulletins from bmw.

To be honest i should watch that Cech video and write it down! I think I'll do that and post it here, just in case anyone wants to do all 3. but doing just one is much more appealing because that area around all those nipples ends up needing a good clean after doing them all!

Thanks


sent from my phone, so probably lots of typos!

I would follow the Dr's advice. Use the link. He's right of course, your not just removing air, but the old fluid together with it's contaminants. The only way to do that is a proper and full flush.

Ian

 

[DrFarkoff]

P.S.

NOTE BENE! The Nipples on the ABS unit are only the Control Circuit

Wheels circuits also need flushed but Making up a funnel and an old filler cap makes it easy (Better if you can use clear tube at the bottom instead of what I did with a bit of 12 mm pvc pipe which is white and usually requires me to be looking down the hole to guess where the level is in the reservoir and to release the brake

Also Leave the rubber insert in "on" the reservoir to prevent "Squirtage" out of the fluid return

AND Finally If you do spill brake fluid Copious amounts of Hot slightly soapy water will save the paintwork and make sure to hose the remnants away as it s toxic to animals, as well as your paintwork but dissipates and is neutralised very quickly by plenty of water

 

[Slipperyeel]

Thank you Mr Farkoff. All good advice. I'm going to look at your link right now. I think I'm already up to speed with some of your tips. But your point about doing it right reassures me I'm on the right track. Already knew that forest of nipples is for the control circuit. To be honest, that's the only fiddly part of the job. The power circuit is straight forward by comparison.

I've got 500ml of brake fluid ready. Hoping that's plenty, along with the bucket of soapy water

I'm going to make that diagram to show which mile does what and in which order ready for the next time!

Thanks gents



sent from my phone, so probably lots of typos!

 

[Slipperyeel]

Mr Farkoff. Thanks again for the link. Very handy indeed. Breaks done yesterday. I was frozen by the end of it! Brrrrrr! But I'm pleased to say the old fluid looked practically new, so nothing like your photos (I did flush it all a year ago - so should be expected i guess).

I did knock up a crib sheet for myself so i can take it out to the bike each year i come around to doing it. Posted below, may be of use to others (a short-cut compared with the comprehensive link above).

It's an easy job, but a funnel would be a great help doing the power circuit.

 

[King Rat]

Thanks to both of you. Mine is 2003 and the brakes have only been done once in the last 6 or 7 years.....probably time to do them again. Steptoe did them last time and it must be 3 years ago now. Any hints on how to get the rear wheel bleed nipple undone? I would rather have dirty fluid than shear the nipple off and have no brake at all. I have been soaking it in Corrosion-X, I hope that will work its way in and free it off. I have stainless nipples kit to replace them with if and when I can get them off.

 

[Slipperyeel]

That sounds familiar. On my old GS the bleed nipple was horribly corroded and it sheered off. Luckily I anticipated this and had nice stainless replacements to hand (Shaw stainless, good well finished parts, perhaps you know them already).

Now that you've had the nipple oiled as it were, maybe get a full kettle of boiling water and slowly pour it over it to get it all hot, then try and unscrew

If the nipple sheers off, then quickly move to the large nut the nipple is screwed into, while it's all warm. That should come out OK. But obviously you'd need to be armed with a replacement nipple for this plan.

 

[King Rat]

That sounds familiar. On my old GS the bleed nipple was horribly corroded and it sheered off. Luckily I anticipated this and had nice stainless replacements to hand (Shaw stainless, good well finished parts, perhaps you know them already).

Now that you've had the nipple oiled as it were, maybe get a full kettle of boiling water and slowly pour it over it to get it all hot, then try and unscrew

If the nipple sheers off, then quickly move to the large nut the nipple is screwed into, while it's all warm. That should come out OK. But obviously you'd need to be armed with a replacement nipple for this plan.

Brilliant advice, thank you - i have the nipple and the large nut in staineless, all ready - kit from Moto (Bins or Works, can't remember which one). O rings and all the bits - just got to make the hole for it to screw into! If I lose a load of fluid, no big deal if I am emptying the system anyway.....good job I have a spare bike to use now incase it all goes pear shaped. It wouldn't be the first time I ridden the bike somewhere with no brakes - its amazing how you adapt your riding!

 

[Slipperyeel]

Sounds like you're all prepared

It'll be fine.

It shouldn't matter too much if you lose some fluid. It'll effectively be bleeding by gravity, so maybe just make sure the reservoirs are full before you start.

 

[Steptoe]

Brilliant advice, thank you - i have the nipple and the large nut in staineless, all ready - kit from Moto (Bins or Works, can't remember which one). O rings and all the bits - just got to make the hole for it to screw into! If I lose a load of fluid, no big deal if I am emptying the system anyway.....good job I have a spare bike to use now incase it all goes pear shaped. It wouldn't be the first time I ridden the bike somewhere with no brakes - its amazing how you adapt your riding!

Wear a rubber glove and have the stainless bleed nipple already screwed into the stainless holder and at your side.

Unscrew the bleed nipple holder (leave the old seized nipple in place in the holder) already fitted into the caliper.
As you turn the holder the last half turn get ready to stick your thumb (rubber gloved hand) into the hole and press down sealing it so no fluid leaks out.
Pick up new stainless holder with your other hand, quickly remove your thumb from caliper and insert new bleed nipple holder and screw down.

Done quickly and smoothly you'll lose no fluid and won't even have to bleed the brakes if you're fast enough. Although as a matter of course you'll bleed the fluid a couple of pumps throughs.

 

[abbocath]

Well well,

I want to change my brake fluid because i don´t know when they have been changed before i bough the bike but after read this i don´t know it i coul do it!... :-(

I going to re-read everything several times!

 

[Slipperyeel]

Well well,

I want to change my brake fluid because i don´t know when they have been changed before i bough the bike but after read this i don´t know it i coul do it!... :-(

I going to re-read everything several times!

It's not so difficult...there are nuances about doing this particular set-up and the members on here are great for tidying up those details (thanks again gents! ).

But if you're not familiar with it, maybe it's best to get an independent to sort it for you. Brakes are a fairly important part of the bikes function .

Oh, you don't mention your bike model and if it had the servo?