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> Heavy braking scares me, It doesn't lock up
911GT2
post Jul 3 2020, 02:32 AM
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I've read over and over here that the stock brakes are sufficient and that the stock brakes should able to lock up the four wheels.

Although my car slows down, I can not get it to lock up. Even so, even considering the age of the car I think brakes are quite poor.

I've got 205 tires so it's not about lack of grip, but on the pedal the end feels quite soft. I've checked the lines, they are all good so only thing I can think of is moisture in the lines.

So after a flush, what's next, a more aggressive pad? Which one would be recommended?
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ChrisFoley
post Jul 3 2020, 06:02 AM
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1) pads with higher COF
2) master cylinder brace (to prevent firewall flex)
3) adjust rear brake regulator
4) adjust pedal free play and rear venting clearance
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wndsrfr
post Jul 3 2020, 06:06 AM
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QUOTE(911GT2 @ Jul 3 2020, 12:32 AM) *

I've read over and over here that the stock brakes are sufficient and that the stock brakes should able to lock up the four wheels.

Although my car slows down, I can not get it to lock up. Even so, even considering the age of the car I think brakes are quite poor.

I've got 205 tires so it's not about lack of grip, but on the pedal the end feels quite soft. I've checked the lines, they are all good so only thing I can think of is moisture in the lines.

So after a flush, what's next, a more aggressive pad? Which one would be recommended?

Install new OEM rubber flex lines....
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Mark Henry
post Jul 3 2020, 06:25 AM
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First I'd try moving the seat up one notch and remember it has no power assist so you do have to push fairly hard.

-If you have no clue if the brake line hoses have ever been replaced now's the time, the inside of old hose swells shut. When bleeding if you have an extraordinarily small amount of fluid being bled is a sure sign that the hose has swelled shut. Weak brakes like you describe and dragging brakes are also signs of bad hoses.
-another cause is the rear calipers venting set incorrectly.
-Bad calipers,pads rotors, etc.

Our cars don't see a lot of road time. but that's not an excuse not to bleed the brakes every couple of years. At most every 3-4 years.
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porschetub
post Jul 3 2020, 06:47 PM
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QUOTE(911GT2 @ Jul 3 2020, 08:32 PM) *

I've read over and over here that the stock brakes are sufficient and that the stock brakes should able to lock up the four wheels.

Although my car slows down, I can not get it to lock up. Even so, even considering the age of the car I think brakes are quite poor.

I've got 205 tires so it's not about lack of grip, but on the pedal the end feels quite soft. I've checked the lines, they are all good so only thing I can think of is moisture in the lines.

So after a flush, what's next, a more aggressive pad? Which one would be recommended?


Do a "vacuum suck out'' and get the old stuff out,better than doing a "pedal pump" out as you avoid moving shit around the system,the master cylinder generally suffers most and the cups can get torn up.
You should get a result if every other thing is good,otherwise you may find the m/cylinder is leaking by causing a soft pedal,it kinda feels like air in the system but its not.
If no luck you need to look @ a R&R of the master cylinder,good luck.
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ClayPerrine
post Jul 3 2020, 09:41 PM
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I suggest you change the flex lines, check the venting clearance, and check the proportioning valve on the firewall. If it is not working correctly, it can cause spongy brakes. So get it rebuilt to be sure.

Contact the Sultan of stopping, @Eric_Shea about the rebuild of the prop valve.

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911GT2
post Jul 5 2020, 06:08 AM
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Thanks guys! (IMG:style_emoticons/default/beerchug.gif)
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Baumgardner
post Jul 5 2020, 06:39 AM
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QUOTE(911GT2 @ Jul 3 2020, 04:32 AM) *

I've read over and over here that the stock brakes are sufficient and that the stock brakes should able to lock up the four wheels.

Although my car slows down, I can not get it to lock up. Even so, even considering the age of the car I think brakes are quite poor.

I've got 205 tires so it's not about lack of grip, but on the pedal the end feels quite soft. I've checked the lines, they are all good so only thing I can think of is moisture in the lines.

So after a flush, what's next, a more aggressive pad? Which one would be recommended?


Been wondering about changing front brake calipers to an upgrade to BMW 320i...

Article:

https://www.pelicanparts.com/techarticles/9...MW_calipers.htm
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porschetub
post Jul 5 2020, 06:03 PM
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[quote name='Baumgardner' date='Jul 6 2020, 12:39 AM' post='2831108']
[quote name='911GT2' post='2830480' date='Jul 3 2020, 04:32 AM']
I've read over and over here that the stock brakes are sufficient and that the stock brakes should able to lock up the four wheels.

Although my car slows down, I can not get it to lock up. Even so, even considering the age of the car I think brakes are quite poor.

I've got 205 tires so it's not about lack of grip, but on the pedal the end feels quite soft. I've checked the lines, they are all good so only thing I can think of is moisture in the lines.

So after a flush, what's next, a more aggressive pad? Which one would be recommended?
[/quote]

Been wondering about changing front brake calipers to an upgrade to BMW 320i...



Many say it isn't an upgrade,general consensus is people don't bother doing this conversion
The stock brakes in good condition are very good.
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ConeDodger
post Jul 5 2020, 06:33 PM
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Over the years, a lot of rear brake regulators got removed and replaced with a brass tee by geniuses who think they know everything...
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Baumgardner
post Jul 6 2020, 08:07 AM
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[quote name='porschetub' date='Jul 5 2020, 08:03 PM' post='2831256']
[quote name='Baumgardner' date='Jul 6 2020, 12:39 AM' post='2831108']
[quote name='911GT2' post='2830480' date='Jul 3 2020, 04:32 AM']
I've read over and over here that the stock brakes are sufficient and that the stock brakes should able to lock up the four wheels.

Although my car slows down, I can not get it to lock up. Even so, even considering the age of the car I think brakes are quite poor.

I've got 205 tires so it's not about lack of grip, but on the pedal the end feels quite soft. I've checked the lines, they are all good so only thing I can think of is moisture in the lines.

So after a flush, what's next, a more aggressive pad? Which one would be recommended?
[/quote]

Been wondering about changing front brake calipers to an upgrade to BMW 320i...



Many say it isn't an upgrade,general consensus is people don't bother doing this conversion
The stock brakes in good condition are very good.
[/quote]

I haven't heard otherwise, so you could very well be correct about that upgrade. I think a lot of the "braking" concerns are the natural reaction to the hyper sensitive power brakes on more modern cars. If you haven't driven a 914 in a long time, your first reaction on braking in a 914 might be "my god, my brakes don't work" as your life flashes before your eyes. (IMG:style_emoticons/default/driving-girl.gif)
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michael7810
post Jul 6 2020, 08:40 AM
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[quote name='Baumgardner' date='Jul 6 2020, 07:07 AM' post='2831387']
[quote name='porschetub' date='Jul 5 2020, 08:03 PM' post='2831256']
[quote name='Baumgardner' date='Jul 6 2020, 12:39 AM' post='2831108']
[quote name='911GT2' post='2830480' date='Jul 3 2020, 04:32 AM']
I've read over and over here that the stock brakes are sufficient and that the stock brakes should able to lock up the four wheels.

Although my car slows down, I can not get it to lock up. Even so, even considering the age of the car I think brakes are quite poor.

I've got 205 tires so it's not about lack of grip, but on the pedal the end feels quite soft. I've checked the lines, they are all good so only thing I can think of is moisture in the lines.

So after a flush, what's next, a more aggressive pad? Which one would be recommended?
[/quote]

Been wondering about changing front brake calipers to an upgrade to BMW 320i...



Many say it isn't an upgrade,general consensus is people don't bother doing this conversion
The stock brakes in good condition are very good.
[/quote]

I haven't heard otherwise, so you could very well be correct about that upgrade. I think a lot of the "braking" concerns are the natural reaction to the hyper sensitive power brakes on more modern cars. If you haven't driven a 914 in a long time, your first reaction on braking in a 914 might be "my god, my brakes don't work" as your life flashes before your eyes. (IMG:style_emoticons/default/driving-girl.gif)
[/quote]

Push harder Michael, she’ll stop (IMG:style_emoticons/default/driving.gif)
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Root_Werks
post Jul 6 2020, 09:31 AM
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As others have said, start with the cheap stuff:

New stock rubber lines (Not SS lines unless you know how to preload them)
Adjust rear pad clearance
Flush the brake fluid if you can

After those two things, see how the brakes feel.
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