DIY Brake and Clutch Fluid Change - The good, the bad and the questions
#1
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DIY Brake and Clutch Fluid Change - The good, the bad and the questions
Thought I'd provide an update on recent weekend 997 DIY. Some pics to follow.
I've had my 997 for nearly a year and added 8K miles. Only 28K on the clock. Bled the brakes on Saturday and yikes was the old fluid dirty. Downright nasty and its possible the prior owner failed to keep up on this. Hard to know.
The brake fluid change seemed fairly simple with a pressure bleeder and the normal procedure. But all cars are unique. The bleed screws on 997 can leak and need to be firmly tightened. Started with outer screw and then the inner screw at the right rear. Seemed as though only fresh oil emerged from the inner screw. Needed to remove the wheels to tighten the bleed screws properly.
Okay now on to the clutch bleed. It’s a general waking nightmare, given the awful location of the bleed screw. It is nearly on top of the tranny/clutch housing and there is barely any room to maneuver. Additionally, I searched for nearly 15 minutes just to locate the nipple. Forum pics really didn’t help locating the nipple. HINT: Locate your head at the right (driver side) half shaft and look for a circular coil. This coil feeds the clutch slave and the bleed nipple is not far from the coil.
Anyway, the tough part is getting the 11m wrench on the nipple to drain the clutch fluid. I used a mini ratchet to break loose the screw and used my hand from there. Not good. Fluid drips using just a ratchet and it is tough to loosen or snug tight the screw with your fingers. Plus maybe I let air into the line. HINT: (Saw in half a mini 11m closed end box wrench). On the first bleed, no use of the pressure bleeder, just gravity with the clutch depressed. This method yielded only 1 1/4 inches of old fluid in the catch bottle tube. Repeat and a little more, but no new fluid showing. Finally, reattached bleeder at 20 psi and lots of fluid through with clutch depressed. Here is where the problem started. Pressure bleeder with clutch depressed pushed lots of air into the clutch line and I lost clutch pressure. Clutch would not come off the floor. After bouts of panic and thoughts of a flatbed truck in my driveway, I got some advice from my local mechanic. He instructed me to get pressure back into the system by slowly pumping the clutch up and down numerous times by hand. After numerous pumps, the bleed screw was to be opened with the clutch pushed to the floor. Air would be released and the process is repeated. After a number of times doing this, I finally got pressure back in the clutch line and the pedal emerged from the floor. A massive relief.
The overall results are somewhat mixed. The clutch is now much smoother and my short shifter is more manageable in 1 to 2nd shifts, particularly in the troublesome shifts back down to 1st. This was a prime reason for the fluid flush. Not great but certainly improved. Less shift noise as well. Other shift points are noticeably improved. On the brake side, the pressure was initially way too soft or spongy. I did a quick small rebleed and the pressure increased. When doing this, I also realized the front left bleed screw on the caliper was leaking. On the second re-bleed, I tapped the calipers with a hockey puck and bled both the inner and outer bleed screws on each wheel. Notice some small bubbles and the brake pressure increased yet again and isn't too far from the original nice hard feel. I suspect there may be some air in the system from the clutch bleed fisaco.
Quick summary on recommendations/questions
1. Pressure bleeder works well/fits in the frunk nicely while working
2. Wheels off to tighten bleed screws properly
3. Bleed screws need to be tightened firmly. I'd consider replacing the screws at the next flush.
4. For the clutch bleed, save yourself tons of frustration. Dremel in half a small box end 11m wrench. That’s all you'll need and allows for fitting the catch bottle drain tube. (a key to monitor the presence of air in the line)
5. Release clutch fluid very slowly or risk getting air into the line.
6. Ramps work fine for the clutch bleed.
7. Removed both rearmost underside panels. This allows you to get your left arm inside a silver colored cross brace.
8. Should the pressure bleeder be used (in extracting clutch fluid)? My mechanic says no and advises to have an assistant push the clutch pedal down as you open the bleed screw.
9 If a pressure bleeder is used, do you open the bleed screw only when the clutch is pressed down? I suspect yes.
10. In jacking the car, I lifted the right side first and placec on jackstands. I started to lift the left side front and the whole front of the car lifted upward. Not good. Any thoughts?
I've had my 997 for nearly a year and added 8K miles. Only 28K on the clock. Bled the brakes on Saturday and yikes was the old fluid dirty. Downright nasty and its possible the prior owner failed to keep up on this. Hard to know.
The brake fluid change seemed fairly simple with a pressure bleeder and the normal procedure. But all cars are unique. The bleed screws on 997 can leak and need to be firmly tightened. Started with outer screw and then the inner screw at the right rear. Seemed as though only fresh oil emerged from the inner screw. Needed to remove the wheels to tighten the bleed screws properly.
Okay now on to the clutch bleed. It’s a general waking nightmare, given the awful location of the bleed screw. It is nearly on top of the tranny/clutch housing and there is barely any room to maneuver. Additionally, I searched for nearly 15 minutes just to locate the nipple. Forum pics really didn’t help locating the nipple. HINT: Locate your head at the right (driver side) half shaft and look for a circular coil. This coil feeds the clutch slave and the bleed nipple is not far from the coil.
Anyway, the tough part is getting the 11m wrench on the nipple to drain the clutch fluid. I used a mini ratchet to break loose the screw and used my hand from there. Not good. Fluid drips using just a ratchet and it is tough to loosen or snug tight the screw with your fingers. Plus maybe I let air into the line. HINT: (Saw in half a mini 11m closed end box wrench). On the first bleed, no use of the pressure bleeder, just gravity with the clutch depressed. This method yielded only 1 1/4 inches of old fluid in the catch bottle tube. Repeat and a little more, but no new fluid showing. Finally, reattached bleeder at 20 psi and lots of fluid through with clutch depressed. Here is where the problem started. Pressure bleeder with clutch depressed pushed lots of air into the clutch line and I lost clutch pressure. Clutch would not come off the floor. After bouts of panic and thoughts of a flatbed truck in my driveway, I got some advice from my local mechanic. He instructed me to get pressure back into the system by slowly pumping the clutch up and down numerous times by hand. After numerous pumps, the bleed screw was to be opened with the clutch pushed to the floor. Air would be released and the process is repeated. After a number of times doing this, I finally got pressure back in the clutch line and the pedal emerged from the floor. A massive relief.
The overall results are somewhat mixed. The clutch is now much smoother and my short shifter is more manageable in 1 to 2nd shifts, particularly in the troublesome shifts back down to 1st. This was a prime reason for the fluid flush. Not great but certainly improved. Less shift noise as well. Other shift points are noticeably improved. On the brake side, the pressure was initially way too soft or spongy. I did a quick small rebleed and the pressure increased. When doing this, I also realized the front left bleed screw on the caliper was leaking. On the second re-bleed, I tapped the calipers with a hockey puck and bled both the inner and outer bleed screws on each wheel. Notice some small bubbles and the brake pressure increased yet again and isn't too far from the original nice hard feel. I suspect there may be some air in the system from the clutch bleed fisaco.
Quick summary on recommendations/questions
1. Pressure bleeder works well/fits in the frunk nicely while working
2. Wheels off to tighten bleed screws properly
3. Bleed screws need to be tightened firmly. I'd consider replacing the screws at the next flush.
4. For the clutch bleed, save yourself tons of frustration. Dremel in half a small box end 11m wrench. That’s all you'll need and allows for fitting the catch bottle drain tube. (a key to monitor the presence of air in the line)
5. Release clutch fluid very slowly or risk getting air into the line.
6. Ramps work fine for the clutch bleed.
7. Removed both rearmost underside panels. This allows you to get your left arm inside a silver colored cross brace.
8. Should the pressure bleeder be used (in extracting clutch fluid)? My mechanic says no and advises to have an assistant push the clutch pedal down as you open the bleed screw.
9 If a pressure bleeder is used, do you open the bleed screw only when the clutch is pressed down? I suspect yes.
10. In jacking the car, I lifted the right side first and placec on jackstands. I started to lift the left side front and the whole front of the car lifted upward. Not good. Any thoughts?
Last edited by cvtbenhogan; 08-05-2013 at 07:03 PM.
#2
Why the heck do you pressure bleed with the clutch depressed?? Air will not get in the system unless reservoir got empty. Lastly i always thought you bleed inner bleed valve first en outer valve....
#3
Rennlist Member
Bleeding the brake system
Procedure for bleeding
1st. Step: Bleed brakes in the normal way (in combination with bleeding device at the brake fluid reservoir
and 2.0 bar pressure) (primary circuit).
2nd. Step: In addition, use the Piwis Tester to bleed the brakes (secondary circuit). Only necessary if the
hydraulic unit has been replaced and, after bleeding in the normal way (primary circuit), the brake pedal travel
is excessive.
1. Step: Bleeding (primary circuit)
Note
· Always bleed both bleeder valves on brake caliper!
· Bleed the outer bleeder valve first!
From WS Manual ... 997
Procedure for bleeding
1st. Step: Bleed brakes in the normal way (in combination with bleeding device at the brake fluid reservoir
and 2.0 bar pressure) (primary circuit).
2nd. Step: In addition, use the Piwis Tester to bleed the brakes (secondary circuit). Only necessary if the
hydraulic unit has been replaced and, after bleeding in the normal way (primary circuit), the brake pedal travel
is excessive.
1. Step: Bleeding (primary circuit)
Note
· Always bleed both bleeder valves on brake caliper!
· Bleed the outer bleeder valve first!
From WS Manual ... 997
#4
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Nice job
I have done this job as well - but my old fluid looked like the new fluid (ate gold). I did not experience any excessive "drip" from the bleeder valves.
I would also recommend that if you have plans to do the transmission fluid, do it during the same service since you will have the under panels removed.
Great write-up
I would also recommend that if you have plans to do the transmission fluid, do it during the same service since you will have the under panels removed.
Great write-up
#5
Quote : [Locate your head at the right (driver side) half shaft and look for a circular coil.] unquote.
Got me struggling a little wondering if you were in the UK, but no, the clutch slave pump is on the left side regardless! Thanks for posting but the job isn't that complicated if you followed the procedure. BTW, procedure requires some fancy pumping of the clutch pedal whilst releasing the fluid. IIRC, 15 smooth pumps in 30 secs. Make sure to have a stopwatch handy
Got me struggling a little wondering if you were in the UK, but no, the clutch slave pump is on the left side regardless! Thanks for posting but the job isn't that complicated if you followed the procedure. BTW, procedure requires some fancy pumping of the clutch pedal whilst releasing the fluid. IIRC, 15 smooth pumps in 30 secs. Make sure to have a stopwatch handy
#6
Rennlist Member
Thread Starter
Quote : [Locate your head at the right (driver side) half shaft and look for a circular coil.] unquote.
Got me struggling a little wondering if you were in the UK, but no, the clutch slave pump is on the left side regardless! Thanks for posting but the job isn't that complicated if you followed the procedure. BTW, procedure requires some fancy pumping of the clutch pedal whilst releasing the fluid. IIRC, 15 smooth pumps in 30 secs. Make sure to have a stopwatch handy
Got me struggling a little wondering if you were in the UK, but no, the clutch slave pump is on the left side regardless! Thanks for posting but the job isn't that complicated if you followed the procedure. BTW, procedure requires some fancy pumping of the clutch pedal whilst releasing the fluid. IIRC, 15 smooth pumps in 30 secs. Make sure to have a stopwatch handy
Now, does anyone have the direction? Or is it time to buy a 997 WS manual?
#7
Tips for the clutch:
-put the car on stands and remove the driver's side rear wheel
-i can't remember but i don't think i even removed the under tray
-crack the bleed with an 11mm socket on a long extension, put the bleed hose on, open the bleeder by hand while a friend pumps, close it by hand, tighten with 11mm socket on extension
-i saw a guy at the track who replaced the bleeder with a banjo bolt and ran a SS braided line to the engine bay with a bleeder there. if you're at the track every weekend may be worth it.
-put the car on stands and remove the driver's side rear wheel
-i can't remember but i don't think i even removed the under tray
-crack the bleed with an 11mm socket on a long extension, put the bleed hose on, open the bleeder by hand while a friend pumps, close it by hand, tighten with 11mm socket on extension
-i saw a guy at the track who replaced the bleeder with a banjo bolt and ran a SS braided line to the engine bay with a bleeder there. if you're at the track every weekend may be worth it.
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#8
Rennlist Member
Thread Starter
Tips for the clutch:
-put the car on stands and remove the driver's side rear wheel
-i can't remember but i don't think i even removed the under tray
-crack the bleed with an 11mm socket on a long extension, put the bleed hose on, open the bleeder by hand while a friend pumps, close it by hand, tighten with 11mm socket on extension
-i saw a guy at the track who replaced the bleeder with a banjo bolt and ran a SS braided line to the engine bay with a bleeder there. if you're at the track every weekend may be worth it.
-put the car on stands and remove the driver's side rear wheel
-i can't remember but i don't think i even removed the under tray
-crack the bleed with an 11mm socket on a long extension, put the bleed hose on, open the bleeder by hand while a friend pumps, close it by hand, tighten with 11mm socket on extension
-i saw a guy at the track who replaced the bleeder with a banjo bolt and ran a SS braided line to the engine bay with a bleeder there. if you're at the track every weekend may be worth it.
I'm intrigued by the entry point here.
#9
[QUOTE=Now, does anyone have the direction? Or is it time to buy a 997 WS manual? [/QUOTE]
I've seen someone eBay workshop DVDs for the 997.1 for a very reasonable price. I downloaded mine for free after a RL member pointed us the way. I can't remember the link now but do a search and you might still find it.
I've seen someone eBay workshop DVDs for the 997.1 for a very reasonable price. I downloaded mine for free after a RL member pointed us the way. I can't remember the link now but do a search and you might still find it.
#10
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Join Date: Oct 2006
Location: Houston, Texas
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Does this help?
Here you go gentleman - I looked through my phone and still had some of the photos from the job I did on the brake and clutch bleed. I got the tubing at Home Depot or Lowes for $.40-.50 per foot. I had an old Brake fluid bottle I use as a catch.
I hope this helps with getting some perspective on the position and location of the clutch bleeder valve. I did not pump the clutch but used my air compressor for help - see first picture...
The other pictures have comments - it is very tight, but if you twist just right you can get in there. I did the job alone - so a helper may ease your work for checking the brake fluid level etc.
I hope this helps with getting some perspective on the position and location of the clutch bleeder valve. I did not pump the clutch but used my air compressor for help - see first picture...
The other pictures have comments - it is very tight, but if you twist just right you can get in there. I did the job alone - so a helper may ease your work for checking the brake fluid level etc.
#13
I remember reading a post awhile back that mentioned just pumping the clutch some 50 times after a brake systems bleed which would circulate the new fluid through the clutch system and then re bleed the brakes. Any thoughts on this method.
#14
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Great photos, very informative to see up close like that!
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#15
Rennlist Member
Important notes on bleeding
The clutch hydraulics must always be filled or bled using a bleeding device. Furthermore, the bleeder valve
must be opened sufficiently and the gauge pressure at the bleeding device must be approx. 1.3 bar.
Once the filling or bleeding process has started, the clutch pedal must be moved (extremely slowly) into the
"Pedal fully depressed" position .
As there is no system pressure, servo kinematic effects will cause the clutch pedal to move forward abruptly.
In order to avoid damage, the pedal must be guided manually.
In general, a minimum filling time of 90 seconds must be observed. Once this filling period has elapsed,
check that no more bubbles appear at the bleeder valve (use a collecting bottle with transparent hose). Only
then close the bleeder valve.
Filling/bleeding
Note
In general, a minimum filling time of 90 seconds must be observed.
Use only new Super DOT 4 class brake fluid. This brake fluid is available under the following part numbers:
•Container quantity 1 litre = 000.043.203.66
•Container quantity 30 litres = 000.043.203.67
1. Remove the cover over the brake fluid reservoir. Fill reservoir to its top edge with new brake fluid.
Connect the bleeding device to the brake fluid reservoir.
2. Switch on the bleeding device and set an overpressure of approx. 1.3 bar.
3. Open the bleeder valve -arrow- on the clutch slave cylinder.
4. Move pedal extremely slowly to the "Pedal fully depressed" position. When doing so, guide the
pedal by hand so that it does not move forward abruptly.
5. Allow the brake fluid to rinse through for 30 seconds.
6. Afterwards, activate complete pedal travel manually very slowly for a further 60 seconds. After
about 10 to 15 pedal strokes, leave the pedal in its normal position. Once this filling period has
elapsed, check that no more bubbles appear at the bleeder valve (use a collecting bottle with
transparent hose). Then close the bleeder valve (tightening torque = 7 + 6 Nm (5 + 4.5 ftlb.).
7. Switch off and disconnect the bleeding device. Check the brake fluid level. It should not be above
the MAX. mark.
8. Activate the clutch pedal slowly, five times.
9. Fit the cover over the brake fluid reservoir.
The clutch hydraulics must always be filled or bled using a bleeding device. Furthermore, the bleeder valve
must be opened sufficiently and the gauge pressure at the bleeding device must be approx. 1.3 bar.
Once the filling or bleeding process has started, the clutch pedal must be moved (extremely slowly) into the
"Pedal fully depressed" position .
As there is no system pressure, servo kinematic effects will cause the clutch pedal to move forward abruptly.
In order to avoid damage, the pedal must be guided manually.
In general, a minimum filling time of 90 seconds must be observed. Once this filling period has elapsed,
check that no more bubbles appear at the bleeder valve (use a collecting bottle with transparent hose). Only
then close the bleeder valve.
Filling/bleeding
Note
In general, a minimum filling time of 90 seconds must be observed.
Use only new Super DOT 4 class brake fluid. This brake fluid is available under the following part numbers:
•Container quantity 1 litre = 000.043.203.66
•Container quantity 30 litres = 000.043.203.67
1. Remove the cover over the brake fluid reservoir. Fill reservoir to its top edge with new brake fluid.
Connect the bleeding device to the brake fluid reservoir.
2. Switch on the bleeding device and set an overpressure of approx. 1.3 bar.
3. Open the bleeder valve -arrow- on the clutch slave cylinder.
4. Move pedal extremely slowly to the "Pedal fully depressed" position. When doing so, guide the
pedal by hand so that it does not move forward abruptly.
5. Allow the brake fluid to rinse through for 30 seconds.
6. Afterwards, activate complete pedal travel manually very slowly for a further 60 seconds. After
about 10 to 15 pedal strokes, leave the pedal in its normal position. Once this filling period has
elapsed, check that no more bubbles appear at the bleeder valve (use a collecting bottle with
transparent hose). Then close the bleeder valve (tightening torque = 7 + 6 Nm (5 + 4.5 ftlb.).
7. Switch off and disconnect the bleeding device. Check the brake fluid level. It should not be above
the MAX. mark.
8. Activate the clutch pedal slowly, five times.
9. Fit the cover over the brake fluid reservoir.