Brake Lines Alloy Trailing Arm Conversion
 

I am converting my 73T to an RSR Clone. I am using a set of later model alloy trailing arms and adjustable spring plates for the conversion. I am also using the original calipers from the 73T. While test fitting all of the components prior to having my trailing arms painted satin black, I noticed that the hard brake lines from the trailing arm to the caliper will not fit (see photo).

I must need the later model hard barake lines. Does anyone know a source and/or the P/N for these lines. http://forums.pelicanparts.com/uploa...1099834728.jpg

I have no idea of a source, but it should be pretty easy to make your own with a length of brake line (with metric fittings) supplied by your local auto parts store.

Rough in the length with a old coat hanger and then buy a length of line that is at least that long. Pick up a $5 tubing bender and use it to make the proper bends.

Thanks for your reply. Sounds like a fun project.

Are the rear calipers Carrera or SC?

Carrera caliper #: 911 355 622 03 & 911 355 621 03 (these have left & right #'s)

SC # : 911 355 621 02 (these are the same left and right)
Regards,
J.P.

You can buy brake lines already made (with fittings) in various lengths at any NAPA or auto parts store. Cheap too, like 2-4 bucks...


I tried posting a link but it wont go to the specific page on NAPA online.com, only to the homepage.

These rear calipers are the steel ones off of my 73T. Different parts right and left.

Brake lines are cheap from the dealer, so are the rear caliper for these alloy arms - check ebay

I don't recall buying new rigid brake lines when I did my conversion ('69-to-'77 arms).

http://forums.pelicanparts.com/uploa...1099875219.jpg

http://forums.pelicanparts.com/uploa...1099876549.jpg

These are the best pics I have. Try to disregard the bleeding setup. I'm guessing you have the right side caliper on the left arm and the line will fit if you re-orient it 180º.

Sherwood

You have the right part, just rotate it 180 degrees.
j.p.
Ps Instead of painting, polish them, makes them stronger too.

OK guys. I am confused with all of the advice. I have been using tha attached photo of an RS restoration that was done at Gunnar Racing. http://forums.pelicanparts.com/uploa...1099909229.jpg

The photo shows the bleed valve on the caliper oriented at the top and appears to show the brake line going through a hole in the original steel trailing arms.

Here's another pic of my trial fit-up.
http://forums.pelicanparts.com/uploa...1099909434.jpg
It shows the bleed valve at the top. So I assume I have the right and left calipers on the correct side. The photo aslo shows a coat hanger template for the new line that I was going to make.

I guess you guys are telling me that I should be able to make the original barake line fit if I orient it correctly.

Have I got it correct??

Well, if its long enough, sure use the original. If you are only about 1" short, you can buy a 1" adapter from any hydraulic shop.
From your pic it looks like you have a weird 'square shape' bend before it goes into the caliper, which is not needed. Basically any which way you can bend the line to make it fit, -as long as it is not rubbing against anything- is fine.

You can't bend the brake line that tight either ... about a 1" radius is as tight as you can go.

did you try flipping the line around the other way, something doesnt look right

Tom:
There is a factory line for this application. I did the same conversion a couple of years ago ( alum arms to 73.5 t with stock 73 m calipers).

Unfortunately I don't have the Porsche part number, but I'm 99% sure that the Pelican number is C-555-621-02. The same part is used for both left and right, and their description makes reference to this -- cost is 12.60 each.

I've included pics below of my install. Your mock up is very close but do note the radius per the above comment.

Good Luck
Joe Frantz

http://forums.pelicanparts.com/uploa...1099950546.jpg

http://forums.pelicanparts.com/uploa...1099950593.jpg

Joe

Thanks for your reply. I think we're getting somewhere. The part you are referring to and the one I believe I need is part # 21 in the attached SC parts diagram taken from our host's website. This makes sense because the M calipers were used from '69 thru '83. I was not able to find the Pelican part number that you referred to when I searched the site. Can anyone help with either the Pelican part number or the Porsche part number. I should be able to get the lines from the dealer once I get the part number.http://forums.pelicanparts.com/uploa...1099960923.jpg

Tom you have the part # in the forth reply/ post.?????
SC # : 911 355 621 02 (these are the same left and right)

Tom,
According to the exploded illustration, #21 is the RF front brake rigid line. I think you may want #8 for the rear brakes (which I believe you already have). Yes?

Sherwood

Thanks...I though the P/N in the 4th reply were for the calipers. I'll check them out at the dealer.

Sherwood...I think you have the exploded diagram backwards. # 8 is for the right front caliper and # 21 is for the rear.

Tom,
My apologies. The number is C-355-621-02. (not C-555 as I originally typed). This number works in the Pelican search -- be sure to include the hyphens.
This also corresponds with the Porsche number in JPAHEMI's post if you replace the "C" with "911", so I'm convinced that this is the part.
Also agree that item #21 in the illustration is the part, but it isn't exactly the same shape in real life.
When I bought mine over the counter at a dealer, the parts guy said there had been a few supersessions.

Joe

"I think you have the exploded diagram backwards. # 8 is for the right front caliper and # 21 is for the rear."

Tom,
My apologies. Yes, it looks like #21 is the rear. In real life, the first bend is a 90º angle that runs the tube downward and parallel to the spring plate, then a bend toward to the caliper inlet as per Joe Frantz's fabricated lines.

It still looks like your current brake line in photo 1 might work if swapped end-for-end, but you know better as you're there.

Sherwood

Yep!!

I just put in an order for C-355-621-02 off our hosts on-line system. Thanks for all of your help on this one.

Tom/Sherwood:
The lines in my pictures are the factory lines -- I didn't fabricate them.
Joe

I think I know why the don't fit.

It looks like you have TURBO rear trailing arms. There is too much offset for the hub and tons of clearance between the caliper and the spring plate. these will not work with your 73 unless you install some camber boxes or move the pickups. in this case, custom lines will be required but that is the least of your worries.

Would a rear brake caliper from a 73T even bolt up to a turbo trailing arm? I thought the turbo trailing arms had 3.5" bolt spacing for the brakes...whereas the carrera/SC trailing arms had 3" bolt spacing. Am I wrong?

Good point Josh, There is just so much clearance compared to what's on my car. You can stick your whole hand behind those. I can barely get a wrench behind my calipers. Maybe its a difference in the year of the arm.

I agree its the wrong brake line.

Jaime and Josh

The P/N stamped on the trailing arms are 911.331.513.OR and 911.331.514.OR. I believe these are the late model 911 trailing arms that were used from 74 thru 89 and should work on my 73. I am planning on using the e-brake assembly, dust shield and hub from the late model assembly and the stub axles from my 73 trailing arms to match with the output flanges from my original 915 gearbox.

The extra clearance that appears in the photo is probably due to the fact that I did not have the hub and stub axle installed when I shot the photo.

Tom,
FWIW, your alloy arms are from a 74-77 911. These early alloy versions use the ball-type drop link connector as seen in your first pic. There are no other differences in the post 77 arms.

Sherwood