Go Back   986 Forum - for Porsche Boxster & Cayman Owners > Porsche Boxster & Cayman Forums > Performance and Technical chat

Reply
 
LinkBack Thread Tools Display Modes
Old 08-16-2015, 09:03 PM   #1
There Is No Substitute.
 
rick3000's Avatar
 
Join Date: May 2007
Location: West Coast
Posts: 3,142
Garage
Motive & Brake Bleeding Questions

I just wrapped up my first brake bleed/flush. I pressured tested the system, poured 2L of ATE Super Gold into a Motive Black Label, then pumped to 15psi. I decided to avoid the hassle of removing the strainer and just pump the old fluid through the system. I began at the right rear outer bleed valve. I got about 800ml, which was likely overkill, but I wanted to make sure I got all of the old fluid out. I then got about 100-150ml from every other valve. I ultimately got about 1.5L out of the system, with about 0.5L left in the bleeder.

I am not quite sure I did everything correctly, so I am hoping for some clarification on the below questions:

-The Motive fill tube had some air bubbles in it for the entire process, I read that it is normal. Is that correct?

-The valves bled very, very slowly. I read to not open the bleed valves more than 1/4 turn, should I have opened the valves more?

-The air bubbles I saw escaping where very tiny, is that normal? I was expecting more like pockets of air between the fluid.

-I had a lot of trouble distinguishing between the new and old fluid. If I did not bleed any of the valves long enough, do I need to be concerned?

-Is it even possible to disconnect the bleed valve tube without getting some brake fluid on the calipers? I wiped what I could, then sprayed the area with water to try and neutralize/dilute any brake fluid that was left on the calipers.

Thank you so much in advance!
-Rick

__________________
1999 Ocean Blue Metallic Boxster - blueboxster.com

Last edited by rick3000; 08-16-2015 at 09:33 PM. Reason: clarity
rick3000 is offline   Reply With Quote
Old 08-17-2015, 06:38 AM   #2
Registered User
 
Join Date: Oct 2014
Location: SE Ma
Posts: 259
Hi Rick, I open the bleeders apx 1/2 turn for a quicker job. I also use the power bleeder dry and just add fluid into the reservoir as I go. I also put a quick disconnect in the hose between the Motive tank and the MC reservoir so I don't have to pump it up every time I add brake fluid. 20 psi works well for me in the tank
Deadeye is offline   Reply With Quote
Old 08-17-2015, 06:46 AM   #3
On the slippery slope
 
JayG's Avatar
 
Join Date: Mar 2014
Location: San Diego
Posts: 3,429
Garage
You are fine

Air bubbles in the motive fill tube is normal/fine. It just keeps up the fluid level in the brake reservoir.

I found the bleed is slow as well and very difficult to see the fluid change. Those morons that outlawed ATE blue should be shot.

When I bled my brakes, I measure the volume as well. IIRC, its around 200 - 250 per caliper with the fronts being less that the rear and clutch. I found the correct amounts in a post here or on rennlist 996 forum. 1 liter is more than enough to do the job

If you open the bleeed screw too much, you can induce air into the stream and that can be the small bubbles you saw
__________________
2004 Boxster S 6 speed - DRL relay hack, Polaris AutoTop DIY
2004 996 Targa Tip
Instructor - San Diego region, 2014 Porsche Performance Driving School
2013 C300, 2010 Jetta 2011 Mazda 3, 1998 Windstar - Dog van , 2004 F-150 "Big Red"
JayG is offline   Reply With Quote
Old 08-17-2015, 07:02 AM   #4
Registered User
 
Join Date: Nov 2006
Location: In the garage...
Posts: 1,599
+2 for using dry

As for your other questions:

Quote:
Originally Posted by rick3000 View Post
-The Motive fill tube had some air bubbles in it for the entire process, I read that it is normal. Is that correct?
Yes, for most part correct. When used dry it's just one big air bubble.

Quote:
Originally Posted by rick3000 View Post
-The valves bled very, very slowly. I read to not open the bleed valves more than 1/4 turn, should I have opened the valves more?
1/4 to 1/2 is sufficient

Quote:
Originally Posted by rick3000 View Post
-The air bubbles I saw escaping where very tiny, is that normal? I was expecting more like pockets of air between the fluid.
Depending on usage for vehicle and time from last flush/bleed - yes normal. Most of old fluid gets expelled by caliper furthest from M/C (right rear in this case). You should 'see' less debris and bubbles as you move closer (and thus require less fluid from each as well). Just like much less fluid needs extracted from outside bleed valve versus inner.

Quote:
Originally Posted by rick3000 View Post
-I had a lot of trouble distinguishing between the new and old fluid. If I did not bleed any of the valves long enough, do I need to be concerned?
If hard to distinguish then fluid was likely in better shape than most. Again, usage dependent but min every 2 years or before each track event.

Quote:
Originally Posted by rick3000 View Post
-Is it even possible to disconnect the bleed valve tube without getting some brake fluid on the calipers? I wiped what I could, then sprayed the area with water to try and neutralize/dilute any brake fluid that was left on the calipers.
Indeed tough and dependent somewhat on length of tube used (tip to go buy a longer one at local hardware store for next time). You can usually finagle most of expelled fluid out of tube being patient for it to siphon out while holding catch container well below caliper after bleeder valve closed when disconnecting. I clean up drips w/ brake cleaner or denatured alcohol (also recommended to clean out Motive bleeder used wet; dry = none needed of course).

Aside from making sure you don't loosen bleeders too much... also do not over tighten.

Your trepidation rises from task being easier than you imagined. It's normal... especially when not simultaneously shelling out ~ $150-200 at shop for them to perform.

Congrats on job well done.
__________________
"Cool Prius!"
- Nobody
Burg Boxster is offline   Reply With Quote
Old 08-17-2015, 07:54 AM   #5
There Is No Substitute.
 
rick3000's Avatar
 
Join Date: May 2007
Location: West Coast
Posts: 3,142
Garage
Thanks for the replies! It did feel too easy.
__________________
1999 Ocean Blue Metallic Boxster - blueboxster.com
rick3000 is offline   Reply With Quote
Old 08-17-2015, 08:07 AM   #6
Registered User
 
Join Date: May 2013
Location: Orange County, California
Posts: 266
Quote:
Originally Posted by Deadeye View Post
Hi Rick, I open the bleeders apx 1/2 turn for a quicker job. I also use the power bleeder dry and just add fluid into the reservoir as I go. I also put a quick disconnect in the hose between the Motive tank and the MC reservoir so I don't have to pump it up every time I add brake fluid. 20 psi works well for me in the tank
Can you explain please explain how you would use it dry? So you have a quick disconnect between the Motive tank and the reservoir. When the tank is still pressurized, you quick disconnect it, open up the reservoir, add fluid, replace cap, then quick connect again?
hancock1701 is offline   Reply With Quote
Old 08-17-2015, 08:19 AM   #7
On the slippery slope
 
JayG's Avatar
 
Join Date: Mar 2014
Location: San Diego
Posts: 3,429
Garage
Quote:
Originally Posted by hancock1701 View Post
Can you explain please explain how you would use it dry? So you have a quick disconnect between the Motive tank and the reservoir. When the tank is still pressurized, you quick disconnect it, open up the reservoir, add fluid, replace cap, then quick connect again?
Yup, that's how you use it dry
You do need to make sure you done run out of fluid in the reservoir, or you will need to re-bleed the entire system

It does save on having to clean the motive
__________________
2004 Boxster S 6 speed - DRL relay hack, Polaris AutoTop DIY
2004 996 Targa Tip
Instructor - San Diego region, 2014 Porsche Performance Driving School
2013 C300, 2010 Jetta 2011 Mazda 3, 1998 Windstar - Dog van , 2004 F-150 "Big Red"
JayG is offline   Reply With Quote
Old 08-17-2015, 05:28 PM   #8
There Is No Substitute.
 
rick3000's Avatar
 
Join Date: May 2007
Location: West Coast
Posts: 3,142
Garage
I will add a quick disconnect, and try keeping the Motive clean next time.
__________________
1999 Ocean Blue Metallic Boxster - blueboxster.com
rick3000 is offline   Reply With Quote
Old 08-17-2015, 05:59 PM   #9
On the slippery slope
 
JayG's Avatar
 
Join Date: Mar 2014
Location: San Diego
Posts: 3,429
Garage
Its not hard to clean. pump the unused fluid back into its can

Rinse it out with water wipe the inside with some paper towels.
then rinse with alcohol (get 90% isopropyl or denatured ) and let it air dry
__________________
2004 Boxster S 6 speed - DRL relay hack, Polaris AutoTop DIY
2004 996 Targa Tip
Instructor - San Diego region, 2014 Porsche Performance Driving School
2013 C300, 2010 Jetta 2011 Mazda 3, 1998 Windstar - Dog van , 2004 F-150 "Big Red"
JayG is offline   Reply With Quote
Old 08-17-2015, 09:42 PM   #10
Registered User
 
Join Date: Jan 2007
Location: BC
Posts: 1,263
Does the OP have a Tip tranny? Otherwise I trust you also bled the clutch...

Oh, and you can still buy the ATE blue.
__________________
2001 Boxster, 5 spd, Seal Grey
clickman is offline   Reply With Quote
Old 08-17-2015, 09:50 PM   #11
There Is No Substitute.
 
rick3000's Avatar
 
Join Date: May 2007
Location: West Coast
Posts: 3,142
Garage
Manual, I also bled the clutch. It took me a while to find the valve. It's pretty far up there. Where are you still finding ATE Blue, I thought it had been outlawed?
__________________
1999 Ocean Blue Metallic Boxster - blueboxster.com
rick3000 is offline   Reply With Quote
Old 10-28-2015, 08:31 PM   #12
Registered User
 
ganseg's Avatar
 
Join Date: Jun 2013
Location: Maple Grove, MN
Posts: 83
If you don't bleed the clutch, does the new fluid work it's way into those lines? At two track events after sessions my clutch was engaging low and didn't come all the way up. Would bleeding it help or is this a different problem? 2001 S with 125k miles. I don't have any history before 100k. Brake fluid has been changed twice in that time (once by PO and now by me.)
__________________
2001 Boxster S, 030 'Sport Chassis', LNE IMS, 18"oem wheels.
ganseg is offline   Reply With Quote
Old 10-28-2015, 08:49 PM   #13
Registered User
 
Steve Tinker's Avatar
 
Join Date: Dec 2008
Location: Queensland, Australia
Posts: 1,522
You have to bleed the clutch separately.
The slave cylinder is not easy to get to ( I remove the triangulated aluminium chassis plate for easier access) but the fluid has to be changed out just like the brake fluid....
__________________
2001 Boxster S (triple black). Sleeping easier with LN Engineering/Flat 6 IMS upgrade, low temp thermostat & underspeed pulley.
2001 MV Agusta F4.
Steve Tinker is offline   Reply With Quote
Old 10-29-2015, 04:56 AM   #14
Registered User
 
ganseg's Avatar
 
Join Date: Jun 2013
Location: Maple Grove, MN
Posts: 83
Thanks for the quick answer. Could bleeding the clutch help with the problem I have had twice?
__________________
2001 Boxster S, 030 'Sport Chassis', LNE IMS, 18"oem wheels.
ganseg is offline   Reply With Quote
Old 10-29-2015, 08:58 PM   #15
Certified Boxster Addict
 
Join Date: Nov 2010
Location: Los Angeles
Posts: 7,616
Quote:
Originally Posted by ganseg View Post
Thanks for the quick answer. Could bleeding the clutch help with the problem I have had twice?
Maybe. Maybe not.

Problem could be the fluid, slave cylinder, or the clutch itself. I'd start by bleeding the clutch and see if that helps (since its easy and cheap compared to the other possibilities).
__________________
1999 996 C2 - sold - bought back - sold for more
1997 Spec Boxster BSR #254
1979 911 SC
POC Licensed DE/TT Instructor
thstone is offline   Reply With Quote
Old 10-31-2015, 10:58 AM   #16
Registered User
 
Join Date: Dec 2009
Location: Orange County, CA
Posts: 1,315
PS: Remember that you need to bleed the clutch with the pedal pushed all the way to the floor (if I remember correctly, the manual asks for "Several seconds..." ) thereafter, you can close the bleeder and pull the pedal back...

Gilles is offline   Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -8. The time now is 09:36 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page