Problem during brake fluid bleeding - Rennlist - Porsche Discussion Forums

Notices
964 Forum
Sponsored By:
Sponsored By:

Problem during brake fluid bleeding

 
Old 12-19-2018, 09:29 AM
  #1  
freno a mano
User
Thread Starter
 
freno a mano's Avatar
 
Join Date: Feb 2014
Location: Genova - Italy
Posts: 197
Default Problem during brake fluid bleeding

Hi everyone,

Few days ago I tried to replace the brake fluid bleeding it from the caliper without putting in pressure the system from the reservoir, something went wrong in the ABS , air came in the line and there was no possibility to bleed the line again, the brake pedal was completely inconsistent and went to the metal, in addition I had the red ABS light on in the dash. I took the car to a specialized garage to have the bleeding done by putting in pressure the system from the reservoir. Doing this the brake pedal gained some consistency and the red light came off. Testing the car, driving hard, the brake was stiil spongy and not consistent as before like there was still some air in the lines. At a certain point, near the end of my ride, the brake pedal became consistent as in the past. How is it possible? If there was some air in the ABS system, is It possible the air vents in the reservoir?

Thanks
freno a mano is offline  
Old 12-19-2018, 12:00 PM
  #2  
cjoenck
Addict
Rennlist Member
 
Join Date: Dec 2007
Location: Chicago, IL
Posts: 249
Default

Are you driving a C2 or a C4? Sounds like you still have air in the system. I would do a complete flush and push fresh fluid through the entire system. Depending on the car you drive, the C2 is easy, the C4 a little more involved.
cjoenck is offline  
Old 12-19-2018, 12:09 PM
  #3  
freno a mano
User
Thread Starter
 
freno a mano's Avatar
 
Join Date: Feb 2014
Location: Genova - Italy
Posts: 197
Default

C2
freno a mano is offline  
Old 12-19-2018, 12:45 PM
  #4  
Rocket Rob
IHI KING!
Rennlist Member

 
Rocket Rob's Avatar
 
Join Date: Aug 2001
Location: Nashua, New Hampshire, USA
Posts: 12,422
Default

How are you bleeding the brakes? Are you using a pressure bleeder? I've had good luck using the wet method with the Motive PowerBleeder. Also, in addition to bleeding the calipers, you can also bleed the brake master itself. Its very tedious but can make a difference to the feel.

https://www.motiveproducts.com/colle...t-bleeder-kits

Rocket Rob is online now  
Old 12-19-2018, 12:58 PM
  #5  
freno a mano
User
Thread Starter
 
freno a mano's Avatar
 
Join Date: Feb 2014
Location: Genova - Italy
Posts: 197
Default

No, the problem came because I haven't used a pressure bleeder the first time.
freno a mano is offline  
Old 12-19-2018, 03:22 PM
  #6  
LouZ
Addict
Rennlist Member

 
LouZ's Avatar
 
Join Date: Oct 2002
Location: Philly Area ----- George Washington took a dump in my backyard!
Posts: 3,934
Default

Look at this thread from a few weeks ago. Note: The Durametric does not activate the C2 ABS, as I had stated! I was successful performing the bleed as I outlined in the thread.

https://rennlist.com/forums/964-foru...-to-bleed.html
LouZ is offline  
Old 12-19-2018, 04:10 PM
  #7  
Goughary
Super User
 
Goughary's Avatar
 
Join Date: Oct 2010
Location: fairfield, CT
Posts: 3,589
Default

Yep that was mine...lol.

Hook a power bleeder to the system and run at least a half bleed bottle out of each caliper and you will likely get all the air. Air can be funny in our cars, as it likes to hide. But a good fresh bleed should be enough for yu. It is a lot easier in a c2 vs a C4...
Goughary is offline  
Old 12-20-2018, 01:45 AM
  #8  
tbennett017
Addict
Rennlist Member
 
tbennett017's Avatar
 
Join Date: May 2007
Location: Portland, Oregon
Posts: 2,265
Default

Yes I concur with the power bleeder (I like the 'wet' method too - more cleanup but it's less risk of introducing air). Also bleeding the brakes in any car by pumping the brake pedal can introduce new problems. It's generally a bad idea as you can cause unnecessary wear in the brake master cylinder seals by pushing them too far. This is more important in older, funkier cars but really it's a habit we should all leave behind.

If you have a location where you can do work on your car, I recommend finding a Motiv Power Bleeder and using it per the directions, also described here on the site. It will provide you with a much more consistent result.

Good luck!
tbennett017 is offline  
Old 12-20-2018, 01:25 PM
  #9  
Steve Weiner-Rennsport Systems
RL Technical Advisor
 
Steve Weiner-Rennsport Systems's Avatar
 
Join Date: May 2001
Location: Portland Oregon
Posts: 11,817
Default

If you were bleeding the system by pumping the pedal, your MC may have failed.
Steve Weiner-Rennsport Systems is offline  
Old 12-20-2018, 03:48 PM
  #10  
freno a mano
User
Thread Starter
 
freno a mano's Avatar
 
Join Date: Feb 2014
Location: Genova - Italy
Posts: 197
Default

Originally Posted by Steve Weiner-Rennsport Systems View Post
If you were bleeding the system by pumping the pedal, your MC may have failed.
Temporary failed and now it's working again, possible?
freno a mano is offline  
Old 12-20-2018, 10:42 PM
  #11  
Steve Weiner-Rennsport Systems
RL Technical Advisor
 
Steve Weiner-Rennsport Systems's Avatar
 
Join Date: May 2001
Location: Portland Oregon
Posts: 11,817
Default

Originally Posted by freno a mano View Post
Temporary failed and now it's working again, possible?
Not really.

MC's are not like salamanders, able to regenerate themselves.
Steve Weiner-Rennsport Systems is offline  
Old 12-20-2018, 10:51 PM
  #12  
Vegas993
Addict
Rennlist Member
 
Vegas993's Avatar
 
Join Date: Apr 2005
Location: Las Vegas, NV
Posts: 758
Default

This may be obvious but did you clamp off the off the overflow hose on brake fluid reservoir before you tried to bleed them?
Vegas993 is offline  
Old 12-21-2018, 06:32 AM
  #13  
freno a mano
User
Thread Starter
 
freno a mano's Avatar
 
Join Date: Feb 2014
Location: Genova - Italy
Posts: 197
Default

Originally Posted by Steve Weiner-Rennsport Systems View Post
Not really.

MC's are not like salamanders, able to regenerate themselves.
:-)
what's strange is that near the end of the ride the brake pedal started to work properly. I was thinking to a sealing or o ring out of his position that a certain point came back to place, is it possible?

If the MC failed do I have to feel the brake pedal spongy also with the engine off and no power assistance?

It could be another component (like vacuum booster) that has "temporary" failed?

Originally Posted by Vegas993 View Post
This may be obvious but did you clamp off the off the overflow hose on brake fluid reservoir before you tried to bleed them?
Do you mean the reservoir cap?

Last edited by freno a mano; 12-21-2018 at 07:47 AM.
freno a mano is offline  
Old 12-21-2018, 01:57 PM
  #14  
cjoenck
Addict
Rennlist Member
 
Join Date: Dec 2007
Location: Chicago, IL
Posts: 249
Default

There is a small overflow pipe coming off the fluid reservoir. When pressure bleeding with a Motive bleeder, you need to clamp off the flexible overflow hose, otherwise you won't be able to pressurize the system. A ratchet vice grip usually works well.
cjoenck is offline  
Old 12-21-2018, 03:47 PM
  #15  
freno a mano
User
Thread Starter
 
freno a mano's Avatar
 
Join Date: Feb 2014
Location: Genova - Italy
Posts: 197
Default

Originally Posted by cjoenck View Post
There is a small overflow pipe coming off the fluid reservoir. When pressure bleeding with a Motive bleeder, you need to clamp off the flexible overflow hose, otherwise you won't be able to pressurize the system. A ratchet vice grip usually works well.
ok, clear.

I did the traditional method, the pressure bleeder has been used by the garage, I think they clamped the overflow pipe.
freno a mano is offline  
 


Thread Tools
Search this Thread

Contact Us About Us Advertising Cookie Policy Privacy Statement Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: