Questions about replacing brake lines
04-20-2006, 09:23 AM
#1
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Questions about replacing brake lines I went down to the new Summit Racing store in McDonnough GA last night and picked up some Earl's brake lines. The Summit store KICKS BUTT by the way!
Three questions:
Does anyone have a link to a write up/how to for replacing the brake lines and/or flushing the brake system?
What brake fluid should I use? I already have about a liter of some Valvoline synthetic DOT 4 I think.
How much fluid will I need?
I plan on doing the Year One Experience track day event this weekend at Road Atlanta so I am going to try to do this tonight.
Seth
Three questions:
Does anyone have a link to a write up/how to for replacing the brake lines and/or flushing the brake system?
What brake fluid should I use? I already have about a liter of some Valvoline synthetic DOT 4 I think.
How much fluid will I need?
I plan on doing the Year One Experience track day event this weekend at Road Atlanta so I am going to try to do this tonight.
Seth
04-21-2006, 09:27 AM
#2
Here is a write up on bleeding the brakes.
BRAKE BLEEDING
Purging air and moisture from your binders
Brake bleeding is something that no sane person finds enjoyable. It can be messy and often involves bodily contortionism to access the bleeder screws. However, properly bled brakes are one of the most vital services you can perform on your car.
When & Why
Many brake problems can be traced to air or contamination of the hydraulic fluid. Leaks at fittings where lines and hoses connect to the master cylinder, calipers and/or wheel cylinders can allow air to enter the system, as can rusted-through brakelines. Also, air is introduced whenever a brake-system component other than the friction material (pads or shoes) is replaced. Air can also appear after moisture gets into the fluid and boils, giving off steam. Two signs of air in the fluid are a noticeable decrease in brake performance and a "spongy" pedal that quickly and nearly effortlessly goes to the floorboard (air compresses easier than fluid).
Fluid Facts
Although a properly functioning brake system is closed to outside corruption, brake fluid still degrades over time. Fluid must withstand heat that can exceed 650 degrees F at the wheel without boiling and also remain in a fluid state during the coldest winters. Furthermore, brake fluid lubricates and fights corrosion on internal parts.
Most brake fluid is hydroscopic: It absorbs water. On the positive side, any moisture that enters the system—through condensation, through rubber parts such as seals and hoses or through an unsealed bottle of brake fluid—is dispersed throughout the fluid. That way, chances of localized corrosion and fluid freezing are minimized. On the other hand, absorbed moisture lowers the fluid's boiling point, raises its freezing point and degrades its anti-corrosion additives. As little as 3% moisture can decrease fluid's performance by 30% and also negate its anti-corrosives. Additionally, standard DOT 3 brake fluid can only absorb up to 7% moisture, after which water droplets—and braking problems—begin to form. Anti-lock brake systems (ABS) are especially affected by moisture because they can cycle as many as 20 times per second. Spongy pedal feel is a sign of moisture in the brake fluid.
Depending on temperature fluctuations and humidity, a brake system can take on as much as 3% water in as little as eight months. It's usually recommended that the fluid be entirely flushed at least every two years or 24,000 miles.
Remember that brake systems are closed, so loss of fluid indicates a problem somewhere. When a master-cylinder reservoir is low, look for the cause instead of just topping it off with fluid. The system either has a leak somewhere or the brake pads are worn, causing the pistons to be more extended and retain more fluid.
DOT Specs
Most do-it-yourselfers are familiar with DOT 3 brake fluid, the grade most commonly recommended for passenger vehicles. The Department of Transportation (DOT) numbers refer to the fluids' minimum boiling points, rated both as "dry" (no moisture in the system) and "wet" (3% moisture). The wet rating is more meaningful for vehicles that don't receive regular fluid flushes.
The two brake-fluid styles: poly glycol ether (commonly known as "glycol") and silicone-based. Glycol-based brake fluid is available in DOT 3, 4, and 5 ratings. It's hydroscopic and compresses less than silicone fluid, which gives a firmer pedal feel. Glycol's main drawback is that it makes paint bubble if it comes in contact with it.
The DOT 5 grade is reserved for silicone-based fluid. Unlike standard glycol fluid, it doesn't eat paint (which is why DOT 5 is popular with the show/collector-car crowd) or absorb water. Theoretically, this makes it a "lifetime" fluid. However, if moisture gets into the silicone fluid, droplets can form and boil, which produces steam and introduces air into the system. Silicone fluid is also more expensive and more compressible than glycol, so it gives a mushier pedal feel. Never mix the two styles of fluid—the system must be completely flushed if changing from silicone to glycol or vice versa.
Two-Person Flushing
Now that we've hammered home the importance of bleeding and flushing brake fluid, here's how to do it properly. The traditional "two-man" method involves one person stepping on the brake pedal (whom we like to call The Pumper) while the other (The Dumper) opens the bleeder screws at the brakes. Verbal communication is critical so that the pedal is never up while the bleeder is open, which draws air into the system.
Bleeding patterns vary for different cars—consult the owner's manual and/or service manual for bleeding order as well as DOT-grade fluid recommendation and any ABS-specific procedures. Rear-wheel drive vehicles are bled beginning at the wheel that's farthest from the master cylinder, then gradually working in: typically right rear, then left rear, then right front and finally left front. Front-wheel drives are sometimes bled in a diagonal pattern.
For the actual 2-person blood-letting, The Pumper begins by slowly and steadily applying pressure to the brake pedal while The Dumper opens the bleeder. This forces fluid through the system. The Pumper alerts The Dumper to close the bleeder before the end of the pedal stroke to avoid damaging the master cylinder. The cycle continues until no more air bubbles are visible in the tubing and bottle. Remember to top off the master cylinder after every few pumps and dumps. Keep the lids on both the master and brake-fluid bottle to minimize sloshing and the opportunity for air to invade the fluid.
Once all air is bled, it makes sense to keep bleeding until fresh fluid emerges from the bleeder. When all wheels have been bled (and also the proportioning/combination valve in some vehicles), top off the master cylinder a final time, replace its lid and discard any remaining "new" brake fluid properly along with the old fluid—otherwise, moisture will accumulate inside the unsealed bottle during storage. Pump the pedal a few times to make sure that it's at least as firm—if not firmer—than in its pre-bleed state. Finally, road-test the brakes in an out-of-the-way place to verify they're functioning properly before driving in real-world conditions.
One-Person Methods
The automotive aftermarket includes a few products designed to make brake bleeding a 1-person operation. The three most common: vacuum pumps, pressure pumps and one-way bleeder screws.
Hand-operated vacuum pumps are the most popular for do-it-yourselfers. Affordable, these units suck fluid out through the bleeder, eliminating pedal pumping. However, air can be drawn in through the bleeders' threads if they don't seal tightly, giving the appearance of air in the system. Follow the instructions that come with the pump to learn its operation and the proper wheel-bleeding order for your car.
Pressure pumps are more expensive than vacuum units and are geared toward the professional mechanic. These units attach to the master cylinder and pressurize the system—then you simply open each bleeder. Some pressure pumps also function as a vacuum. They purge air from the brake system and also "bench bleed" master cylinders before they're installed.
One scenario in which air can enter the system while using a 1-person pump is when dirty bleeders' threads don't seal. If using one of these units, consider first removing each bleeder, then cleaning it and its wheel cylinder/caliper hole with brake cleaner before reinstalling.
One-way bleeder screws are a fairly recent boon for the lone brake bleeder. When opened, their check valve allows fluid out but springs shut before air can enter. Best of all, these bleeders are affordable and apply pressure.
When all's said and done, brake bleeding/flushing is one of the least-enjoyable ways to spend up to an hour. While you're thinking of all those things you'd rather do, though, remember that bleeding brakes saves human bloodshed.
Resources
ATE (Super Blue, Super Gold), www.ate-brakes.com
Bendix/Allied Signal, www.bendixbrakes.com
Classic Tube, www.classictube.com
Earl's Performance Products, www.holley.com
MityVac, www.mityvac.com
Phoenix Systems, www.phxsyss.com
Russell Performance Products, www.russellperformance.com
Stainless Steel Brakes Co., www.stainlesssteelbrakes.com
Super Blue, www.superblue.com
BRAKE BLEEDING
Purging air and moisture from your binders
Brake bleeding is something that no sane person finds enjoyable. It can be messy and often involves bodily contortionism to access the bleeder screws. However, properly bled brakes are one of the most vital services you can perform on your car.
When & Why
Many brake problems can be traced to air or contamination of the hydraulic fluid. Leaks at fittings where lines and hoses connect to the master cylinder, calipers and/or wheel cylinders can allow air to enter the system, as can rusted-through brakelines. Also, air is introduced whenever a brake-system component other than the friction material (pads or shoes) is replaced. Air can also appear after moisture gets into the fluid and boils, giving off steam. Two signs of air in the fluid are a noticeable decrease in brake performance and a "spongy" pedal that quickly and nearly effortlessly goes to the floorboard (air compresses easier than fluid).
Fluid Facts
Although a properly functioning brake system is closed to outside corruption, brake fluid still degrades over time. Fluid must withstand heat that can exceed 650 degrees F at the wheel without boiling and also remain in a fluid state during the coldest winters. Furthermore, brake fluid lubricates and fights corrosion on internal parts.
Most brake fluid is hydroscopic: It absorbs water. On the positive side, any moisture that enters the system—through condensation, through rubber parts such as seals and hoses or through an unsealed bottle of brake fluid—is dispersed throughout the fluid. That way, chances of localized corrosion and fluid freezing are minimized. On the other hand, absorbed moisture lowers the fluid's boiling point, raises its freezing point and degrades its anti-corrosion additives. As little as 3% moisture can decrease fluid's performance by 30% and also negate its anti-corrosives. Additionally, standard DOT 3 brake fluid can only absorb up to 7% moisture, after which water droplets—and braking problems—begin to form. Anti-lock brake systems (ABS) are especially affected by moisture because they can cycle as many as 20 times per second. Spongy pedal feel is a sign of moisture in the brake fluid.
Depending on temperature fluctuations and humidity, a brake system can take on as much as 3% water in as little as eight months. It's usually recommended that the fluid be entirely flushed at least every two years or 24,000 miles.
Remember that brake systems are closed, so loss of fluid indicates a problem somewhere. When a master-cylinder reservoir is low, look for the cause instead of just topping it off with fluid. The system either has a leak somewhere or the brake pads are worn, causing the pistons to be more extended and retain more fluid.
DOT Specs
Most do-it-yourselfers are familiar with DOT 3 brake fluid, the grade most commonly recommended for passenger vehicles. The Department of Transportation (DOT) numbers refer to the fluids' minimum boiling points, rated both as "dry" (no moisture in the system) and "wet" (3% moisture). The wet rating is more meaningful for vehicles that don't receive regular fluid flushes.
The two brake-fluid styles: poly glycol ether (commonly known as "glycol") and silicone-based. Glycol-based brake fluid is available in DOT 3, 4, and 5 ratings. It's hydroscopic and compresses less than silicone fluid, which gives a firmer pedal feel. Glycol's main drawback is that it makes paint bubble if it comes in contact with it.
The DOT 5 grade is reserved for silicone-based fluid. Unlike standard glycol fluid, it doesn't eat paint (which is why DOT 5 is popular with the show/collector-car crowd) or absorb water. Theoretically, this makes it a "lifetime" fluid. However, if moisture gets into the silicone fluid, droplets can form and boil, which produces steam and introduces air into the system. Silicone fluid is also more expensive and more compressible than glycol, so it gives a mushier pedal feel. Never mix the two styles of fluid—the system must be completely flushed if changing from silicone to glycol or vice versa.
Two-Person Flushing
Now that we've hammered home the importance of bleeding and flushing brake fluid, here's how to do it properly. The traditional "two-man" method involves one person stepping on the brake pedal (whom we like to call The Pumper) while the other (The Dumper) opens the bleeder screws at the brakes. Verbal communication is critical so that the pedal is never up while the bleeder is open, which draws air into the system.
Bleeding patterns vary for different cars—consult the owner's manual and/or service manual for bleeding order as well as DOT-grade fluid recommendation and any ABS-specific procedures. Rear-wheel drive vehicles are bled beginning at the wheel that's farthest from the master cylinder, then gradually working in: typically right rear, then left rear, then right front and finally left front. Front-wheel drives are sometimes bled in a diagonal pattern.
For the actual 2-person blood-letting, The Pumper begins by slowly and steadily applying pressure to the brake pedal while The Dumper opens the bleeder. This forces fluid through the system. The Pumper alerts The Dumper to close the bleeder before the end of the pedal stroke to avoid damaging the master cylinder. The cycle continues until no more air bubbles are visible in the tubing and bottle. Remember to top off the master cylinder after every few pumps and dumps. Keep the lids on both the master and brake-fluid bottle to minimize sloshing and the opportunity for air to invade the fluid.
Once all air is bled, it makes sense to keep bleeding until fresh fluid emerges from the bleeder. When all wheels have been bled (and also the proportioning/combination valve in some vehicles), top off the master cylinder a final time, replace its lid and discard any remaining "new" brake fluid properly along with the old fluid—otherwise, moisture will accumulate inside the unsealed bottle during storage. Pump the pedal a few times to make sure that it's at least as firm—if not firmer—than in its pre-bleed state. Finally, road-test the brakes in an out-of-the-way place to verify they're functioning properly before driving in real-world conditions.
One-Person Methods
The automotive aftermarket includes a few products designed to make brake bleeding a 1-person operation. The three most common: vacuum pumps, pressure pumps and one-way bleeder screws.
Hand-operated vacuum pumps are the most popular for do-it-yourselfers. Affordable, these units suck fluid out through the bleeder, eliminating pedal pumping. However, air can be drawn in through the bleeders' threads if they don't seal tightly, giving the appearance of air in the system. Follow the instructions that come with the pump to learn its operation and the proper wheel-bleeding order for your car.
Pressure pumps are more expensive than vacuum units and are geared toward the professional mechanic. These units attach to the master cylinder and pressurize the system—then you simply open each bleeder. Some pressure pumps also function as a vacuum. They purge air from the brake system and also "bench bleed" master cylinders before they're installed.
One scenario in which air can enter the system while using a 1-person pump is when dirty bleeders' threads don't seal. If using one of these units, consider first removing each bleeder, then cleaning it and its wheel cylinder/caliper hole with brake cleaner before reinstalling.
One-way bleeder screws are a fairly recent boon for the lone brake bleeder. When opened, their check valve allows fluid out but springs shut before air can enter. Best of all, these bleeders are affordable and apply pressure.
When all's said and done, brake bleeding/flushing is one of the least-enjoyable ways to spend up to an hour. While you're thinking of all those things you'd rather do, though, remember that bleeding brakes saves human bloodshed.
Resources
ATE (Super Blue, Super Gold), www.ate-brakes.com
Bendix/Allied Signal, www.bendixbrakes.com
Classic Tube, www.classictube.com
Earl's Performance Products, www.holley.com
MityVac, www.mityvac.com
Phoenix Systems, www.phxsyss.com
Russell Performance Products, www.russellperformance.com
Stainless Steel Brakes Co., www.stainlesssteelbrakes.com
Super Blue, www.superblue.com
04-21-2006, 09:28 AM
#3
Info on Brake fluid.
Brake Fluid Comparison
This information was compiled by Gary (ghackney@iglou.com) and posted to the Saturn Performance Club Mailing List. If you benefit from this info, be sure to send him a thank you.
"Here's the results of a couple days web research.
The BP After 3-months and 6-months columns are estimates based on a page I found that says brake fluid gains about 3.5% moisture per year, which is where the wet boiling point is measured. Assuming linear degradation this column is where you'd be.
The last two columns may be confusing. They're the price per ounce, divided by the degrees F the fluid exceeds the dry or wet DOT spec; sort of a price for performance number where lower is better. Yeah, I'm an engineer.
FWIW: My conclusion: ATE Type 200 and Super Blue are not only the cheapest of the performance brake fluids, they are also the cheapest per degree of boil protection, and have a very high 6-month BP estimate. In addition you can alternate with each change and the color difference will tell you when you're done. Available from ogracing.com.
Fluid
Dry BP
Wet BP
Approx BP after 3 mo.
Approx BP after 6 mo.
US $/oz
US $/oz per °F > DOT4
Dry
Wet
Castrol SRF
590
518
572
554
2.076
.0144
.0100
NEO Super DOT
585
421
544
503
0.983
.0071
.0089
Motul Racing 600
585
421
544
503
0.712
.0051
.0065
Wilwood Hi-temp 570
570
284
499
427
0.496
.0040
[.0184]
AFCO Racing (570 Gold)
570
0.500
.0040
AP600
572
378
524
475
1.062
.0084
.0159
Ford Heavy Duty DOT3
550
290
485
420
Performance Friction Z-Rated
550
284
484
417
0.492
.0047
[.0182]
ATE Type 200/ATE Super Blue
536
392
500
464
0.295
.0033
.0036
AP550
531
261
464
396
0.648
.0076
[.0130]
Valvoline High Perf Synthetic
513
333
468
423
Motul DOT 5.1
509
365
473
437
0.675
.0107
.0125
ATE SL
500+
DOT 5 Spec
500
346
462
423
Castrol LMA
450
311
415
381
0.219
.0547
DOT 4 Spec
446
311
412
379
DOT 3 Spec
401
284
372
343
You can download Gary's spreadsheet of this info here: Excel, Lotus 1-2-3.
Comments:
I found all this on the web and nothing is guaranteed to be correct.
Wet boiling point is measured at 3.5% moisture, typical for one-year-old fluid.
AP600 is not compatibile with any other fluid.
Ford HD DOT3 is cheap and good for racing but has a low wet boiling point.
ATE Type 200/Super Blue is recommended by BMW.
ATE SL is OE on many European performance cars.
Martel Bros. offers a 5% discount if you mention their web site when ordering.
URL's for the above fluids plus other good info:
http://www.panteracars.com/motul.html (VERY informative)
http://www.neosyntheticoil.com/bkfluid.htm
http://www.martelbros.com/wilwood/59.htm
http://www.afcoracing.com/products/getproduct.cfm
?CategoryID=3&ClassID=28&SubclassID=93&ProductID=1 868
http://www.racerpartswholesale.com/bkfld.htm
http://www.easystreet.com/~porsche/2c.html
http://www.muller.net/karting/docs/t...l/brfluid.html
http://www.diac.com/~cguy1/bmw/text/FAQ/FAQ.13.html
http://www.c-edge.com/shotimes/SHO3brakefluid.html
http://209.19.107.64/ogshell/loadpag...6+catbrak.html
Brake Fluid Comparison
This information was compiled by Gary (ghackney@iglou.com) and posted to the Saturn Performance Club Mailing List. If you benefit from this info, be sure to send him a thank you.
"Here's the results of a couple days web research.
The BP After 3-months and 6-months columns are estimates based on a page I found that says brake fluid gains about 3.5% moisture per year, which is where the wet boiling point is measured. Assuming linear degradation this column is where you'd be.
The last two columns may be confusing. They're the price per ounce, divided by the degrees F the fluid exceeds the dry or wet DOT spec; sort of a price for performance number where lower is better. Yeah, I'm an engineer.
FWIW: My conclusion: ATE Type 200 and Super Blue are not only the cheapest of the performance brake fluids, they are also the cheapest per degree of boil protection, and have a very high 6-month BP estimate. In addition you can alternate with each change and the color difference will tell you when you're done. Available from ogracing.com.
Fluid
Dry BP
Wet BP
Approx BP after 3 mo.
Approx BP after 6 mo.
US $/oz
US $/oz per °F > DOT4
Dry
Wet
Castrol SRF
590
518
572
554
2.076
.0144
.0100
NEO Super DOT
585
421
544
503
0.983
.0071
.0089
Motul Racing 600
585
421
544
503
0.712
.0051
.0065
Wilwood Hi-temp 570
570
284
499
427
0.496
.0040
[.0184]
AFCO Racing (570 Gold)
570
0.500
.0040
AP600
572
378
524
475
1.062
.0084
.0159
Ford Heavy Duty DOT3
550
290
485
420
Performance Friction Z-Rated
550
284
484
417
0.492
.0047
[.0182]
ATE Type 200/ATE Super Blue
536
392
500
464
0.295
.0033
.0036
AP550
531
261
464
396
0.648
.0076
[.0130]
Valvoline High Perf Synthetic
513
333
468
423
Motul DOT 5.1
509
365
473
437
0.675
.0107
.0125
ATE SL
500+
DOT 5 Spec
500
346
462
423
Castrol LMA
450
311
415
381
0.219
.0547
DOT 4 Spec
446
311
412
379
DOT 3 Spec
401
284
372
343
You can download Gary's spreadsheet of this info here: Excel, Lotus 1-2-3.
Comments:
I found all this on the web and nothing is guaranteed to be correct.
Wet boiling point is measured at 3.5% moisture, typical for one-year-old fluid.
AP600 is not compatibile with any other fluid.
Ford HD DOT3 is cheap and good for racing but has a low wet boiling point.
ATE Type 200/Super Blue is recommended by BMW.
ATE SL is OE on many European performance cars.
Martel Bros. offers a 5% discount if you mention their web site when ordering.
URL's for the above fluids plus other good info:
http://www.panteracars.com/motul.html (VERY informative)
http://www.neosyntheticoil.com/bkfluid.htm
http://www.martelbros.com/wilwood/59.htm
http://www.afcoracing.com/products/getproduct.cfm
?CategoryID=3&ClassID=28&SubclassID=93&ProductID=1 868
http://www.racerpartswholesale.com/bkfld.htm
http://www.easystreet.com/~porsche/2c.html
http://www.muller.net/karting/docs/t...l/brfluid.html
http://www.diac.com/~cguy1/bmw/text/FAQ/FAQ.13.html
http://www.c-edge.com/shotimes/SHO3brakefluid.html
http://209.19.107.64/ogshell/loadpag...6+catbrak.html
