Rennlist - Porsche Discussion Forums

Before you start:

Parts needed:
Brake lines, brake fluid (also a good time to check/change pads;adjust emergency brake, paint calipers, etc... :D )

NOTE: YOU WILL NEED TO BLEED THE BRAKES AFTER REPLACING BRAKE LINES. Also a good time to bleed the clutch slave cylinder.

To do Stainless Steel lines or not to use Stainless Steel lines?

Quote:

Originally Posted by Bill Gregory

As Pete pointed out, stock rubber lines should be changed after around 10 years, as they can swell internally and impact hydraulic operation. As a contrarian on this, I don't recommend stainless lines as a neccessary upgrade for 964's. They seem to make more of a difference on earlier 911's. Even the factory today uses rubber lines (although I believe the part number may be different than stock).

Quote:

Originally Posted by Cupcar

I did change to braided stainless and can't say if they made a difference or not as I changed from stock to Porterfield pads at same time. The pedal feel was much better after changing both, I just can't say why since I changed 2 variables. ABS seems to work OK.

I did learn the following things to watch out for:

1) Use the small diameter -3 tubing, it has the lowest volume expansion to pressure curve.

2) Use DOT approved lines as they are more durable than the non DOT teflon lines. I think they are reinforced with Keflar between tubing and stainless, but I'm not really sure of difference.

3)Make sure the ends of new line have the "D" shaped end correctly made to fit into the "D" shaped hole in the chassis bracket. The "D" shape has to be on both sides of the retaining groove, otherwise you have to file the flat on end of line like I did.

In my case I went with DOT approved SS lines. Why? Honestly, price. For around US$60.00, for all four, the cost was less than going with original lines... they look better (for the first few days anyway, until dirt gets to them), and it is another conversation piece ("yeah, I got those SS lines that they were discussing on Rennlist :D " )

New Lines:

First photo shows old front line vs new lines...

http://forums.rennlist.com/upload/bline1.jpg

Notice the two D-shaped lines. Those D-shaped ends are needed to fit the front brackets. Make sure you get them that way when you buy them. Again, the D is only needed for the front lines as the rear line brackets are round.

http://forums.rennlist.com/upload/bline4.jpg

Brake fluid. See other posts on what to use... in my case I already had two cans of ATE Blue... if I had to do it over again I would go with the ATE Gold (less mess if you get brake fluid anywhere as the blue dye stains everything). A few folks alternate between gold and blue to make it easier to know when to stop bleeding.

Special tools:

18mm, 17mm, 14mm and 11mm needed - When loosening the adapter use only a Flare Nut Wrench only to avoid damage to the flair adapter:

http://forums.rennlist.com/upload/sk373.jpg

Once loose you can use a normal open wrench. You will also need a large flat screwdriver and some good pliers.

What about bleeding/flushing the brakes? There are many techniques out there... me, I recommend you get one of those Motive Power Bleeders. One man job and less mess to deal with.

Also, there is no need for the special Bosch tool (also known as The Hammer) if you have a C2 or even if you have a C4 (unless you are also bleeding the Diff locks):

Quote:

Originally Posted by Marc Shaw

Have a look here.

Power Bleeders can't flush the ABS or PDAS systems - you do need the Hammer for that. Diff lock switch alone won't do it, AFAIK.

Marc
P.S. A good place to find DIY stuff is the DIY Forum and the Search function ("Search this Forum" at the top of the forum). :)

Enough already! How do I start??

Start by placing the car on jack stands or a lift. You could do it one/two wheels at a time… but since this will require getting under the car and bleeding all lines, going around, etc. best to just have the thing up on all four wheels. It is a good time to check/replace pads since most of the work is the same.

USE ALL SAFETY PREACAUTIONS WHEN RAISING AND SECURING THE CAR. If the stress is too much, take it to a pro. You should not fool around with the brakes if you don’t have some level of mechanical experience… you know, brakes are somewhat needed when trying to stop the car…

Once up and secured, remove wheels and locate the caliper. Clean the area with some brake cleaner.

Let's start by loosening the flare adapter. Place a canister/bucket/oil catcher under the area because brake fluid will come out as you start to loosen the flair adapter.

Quote:

Originally Posted by JasonAndreas

At least on a C2 you should pump the brake pedal about 20-30 times before you open a brake line to get rid of all the pressure. And to keep fluid from leaking out of the lines just push the brake pedal down about halfway and use a piece of wood or something wedged in front of the seat to keep it there. If the pedal is pushed down while the lines are open the fluid will stay in the lines.

http://forums.rennlist.com/upload/blines11.jpg

http://forums.rennlist.com/upload/blines12.jpg

Loosen the flair adapter with a 11mm flair nut wrench. Use a 17mm wrench in the back to hold the rest of the line and to avoid damage to the notch in the metal bracket:

Quote:

Originally Posted by chris walrod

...When breaking loose hydraulic lines such as brake lines, it really helps to be very deliberate when cracking fittings loose. In other words, a nice sharp blow to the wrench (with your hands) is best.

The hardline fitting located at the front caliper has been know to break off while removing. The above mentioned 'sharp blow' helps avoid this..

Like stressed above, flare wrenches are a must!! The cost of these wrenches is quickly offset by not needing to buy new fittings etc.

http://forums.rennlist.com/upload/blines16.jpg

Then remove the clip holding the line. I start with a large flat screwdriver and with a twist the clip comes out enough to then pull it with the pliers (anyone with a better technique please chime in):

http://forums.rennlist.com/upload/blines15.jpg