Brake fluid flush questions

[Cubieman]

Thanks for that additional info!
Would anyone see an issue with me running INPA to make sure that I can active the purge/bleed routine before I start the job?
Is there any harm that could come of running the ABS with all bleeders etc. closed?
I cannot imagine why there would be a problem as the ABS pump runs when in it is requested to do so normally while the system is closed, but thought I would ask.

[r4dr]

I would expect the pump’s ABS routine and bleeding routines are not the same.

[timmo]

Thanks for that additional info!
Would anyone see an issue with me running INPA to make sure that I can active the purge/bleed routine before I start the job?
Is there any harm that could come of running the ABS with all bleeders etc. closed?
I cannot imagine why there would be a problem as the ABS pump runs when in it is requested to do so normally while the system is closed, but thought I would ask.

Should be fine, I think that's what the50skid did in his video

[HighOnLSB]

This is the first time seeing INPA/DIS being mentioned for bleeding brakes. Is it necessary to have in order to DIY this job? Or is there a manual way to get around it and still be able to bleed the ABS pump?

For example, this DIY makes no mention of needing a laptop or INPA/DIS software. Am I safe to just follow all the steps outlined here?

http://m3.madrussian.net/diy_brake_bleed.shtml

[eacmen]

This is the first time seeing INPA/DIS being mentioned for bleeding brakes. Is it necessary to have in order to DIY this job? Or is there a manual way to get around it and still be able to bleed the ABS pump?

For example, this DIY makes no mention of needing a laptop or INPA/DIS software. Am I safe to just follow all the steps outlined here?

http://m3.madrussian.net/diy_brake_bleed.shtml

Unless you suspect there is air in the ABS (i.e. if your brake fluid reservoir went dry or you replaced the MC, etc) then there really is no need to bleed the ABS with INPA.

I was chasing a soft pedal for a long time. The INPA bleed did not fix it.

So no it's not necessary. If you're really anal about getting all new fluid into every part of the system then it might be a worthwhile investment.

[Cubieman]

Unless you suspect there is air in the ABS (i.e. if your brake fluid reservoir went dry or you replaced the MC, etc) then there really is no need to bleed the ABS with INPA.

I was chasing a soft pedal for a long time. The INPA bleed did not fix it.

So no it's not necessary. If you're really anal about getting all new fluid into every part of the system then it might be a worthwhile investment.

Good to hear, I am not messing with the ABS if that is the case.

[HighOnLSB]

Good info thanks eacmen! I will be doing a full fluid flush when installing my 996 calipers and was curious about this step. I will keep it in mind to keep some fluid in the reservoir to avoid needing to bleed the ABS if that is the case.

[bimmer]

The schwaben one is nicer than the Motive one. If I didnt have the Motive already I would buy the Schwaben one. The black label cap is worth it, otherwise your stuck trying to thread the cap on with the hose not able to rotate.

For anyone with the motive power bleeder or thinking of buying one, just get yourself some brass quick connects for a few dollars at the hardware store. Solves the twisting hose problem and makes life much easier.

[Dino]

Just finished flushing and bleeding my brakes. The video below shows that the clutch uses the same brake fluid from the reservoir to bleed the clutch. Does anyone know if this is the same method for an SMG car or do you only do this if you have a manual? I will be using a Motive Power Bleeder.

https://www.youtube.com/watch?v=fKogyC5mvVs

[eacmen]

Just finished flushing and bleeding my brakes. The video below shows that the clutch uses the same brake fluid from the reservoir to bleed the clutch. Does anyone know if this is the same method for an SMG car or do you only do this if you have a manual? I will be using a Motive Power Bleeder.

https://www.youtube.com/watch?v=fKogyC5mvVs

I believe the hydraulic fluid from the SMG reservoir is used to operate the clutch slave cylinder. Not brake fluid. If you want to bleed the SMG system its a whole different ball game requiring INPA. Otherwise if it ain't broke dont fix it.

[Dino]

I believe the hydraulic fluid from the SMG reservoir is used to operate the clutch slave cylinder. Not brake fluid. If you want to bleed the SMG system its a whole different ball game requiring INPA. Otherwise if it ain't broke dont fix it.

Perfect.

Thank you for the quick reply!

[beefaroni]

Unless you suspect there is air in the ABS (i.e. if your brake fluid reservoir went dry or you replaced the MC, etc) then there really is no need to bleed the ABS with INPA.

I was chasing a soft pedal for a long time. The INPA bleed did not fix it.

So no it's not necessary. If you're really anal about getting all new fluid into every part of the system then it might be a worthwhile investment.

What ended up being the cause for your soft pedal? I still have the rear calipers to replace on mine but I have a little bit of a soft pedal. Sorry to threadjack

[Arith2]

When doing a routine flush DO NOT bleed the ABS module. It puts unnecessary wear on it and you run the risk of actually getting air in it. Unless the module is being used, it's just a straight through flow. It uses solenoids to push and release the brakes. It should not be messed with unless you think there's air in it. Everytime you turn the car on, it cycles and primes to make sure it works. There is a very small chance there will be old fluid in it.

Our modules fail as it is. There's no reason to increase the chances. SMG system is also a completely separate, dedicated system. Software is the only way to bleed that system.

[eacmen]

What ended up being the cause for your soft pedal? I still have the rear calipers to replace on mine but I have a little bit of a soft pedal. Sorry to threadjack

Never really solved it to my satisfaction actually. But it did get considerably better when combining the pressure bleed with actuating the brake pedal with a bleeder open. My flush procedure before each track day now is:

1. Hook up pressure bleeder. Usually use 20psi
2. Open each valve. Leave it cracked flowing slow.
3. Press brake pedal a few times. I stop right before it bottoms out to avoid damaging MC seals.
4. Bleed/Flush as normal, tapping the caliper with rubber mallet while bleeding.

Remember that air likes to flow up. So if you suspect air in there and it won't come out elevate the read end while bleeding rear and elevate the front while bleeding front.

[Cubieman]

When doing a routine flush DO NOT bleed the ABS module. It puts unnecessary wear on it and you run the risk of actually getting air in it. Unless the module is being used, it's just a straight through flow. It uses solenoids to push and release the brakes. It should not be messed with unless you think there's air in it. Everytime you turn the car on, it cycles and primes to make sure it works. There is a very small chance there will be old fluid in it.

Our modules fail as it is. There's no reason to increase the chances. SMG system is also a completely separate, dedicated system. Software is the only way to bleed that system.

Good to know, I didn't mess with the ABS on my recent brake flush.