Rear Drum Brake Spring Location

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Scott McAdams
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Rear Drum Brake Spring Location

#1 Post by Scott McAdams » Wed Jan 09, 2019 4:30 am

Hi. I finally got a chance to pull the rear, driver side brake drum on my 356B. I had been hearing a rattling back there for a while. At first glance, things looked in order, but upon closer inspection, I think the PO may have put the top spring in the wrong hole (see pic). Specifically, I think the left side of the top spring should terminate in the hole that I have circled in red, not in its current position. I checked the diagram from the 356 Parts catalog, but it only shows half the drum brake. Can anyone confirm that the circled red hole is indeed the correct spot to terminate the spring? I think this would explain the rattle as the spring is not currently flexed enough to keep the plate below it from rattling around.

Thank you so much for your help.
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356B S90 Roadster, '60
Macan Turbo, '15
Cayenne, '08
C4S, '08
Targa, '84

Erik Thomas
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Location: Rhode Island

Re: Rear Drum Brake Spring Location

#2 Post by Erik Thomas » Wed Jan 09, 2019 7:56 am

Scott: As you have determined, the upper spring should be contacting the notch on the top of the push bar. And yes, move the spring to the hole you have circled. I am dealing with a similar issue - my car had the right hand side push bar used on both left and right and it did rattle. It is not easy to stretch this spring so far, I clamp the spring in the jaws of a pair of vice grips which makes the stretch controllable. Make sure you have the correct spring, and not a VW wanna be.

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Vic Skirmants
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Re: Rear Drum Brake Spring Location

#3 Post by Vic Skirmants » Wed Jan 09, 2019 9:01 am

Erik Thomas wrote:Scott: As you have determined, the upper spring should be contacting the notch on the top of the push bar. And yes, move the spring to the hole you have circled. I am dealing with a similar issue - my car had the right hand side push bar used on both left and right and it did rattle. It is not easy to stretch this spring so far, I clamp the spring in the jaws of a pair of vice grips which makes the stretch controllable. Make sure you have the correct spring, and not a VW wanna be.
Good trick for that top spring. Assemble the shoes with the bar and spring, add the parking brake cable, slide the tops of the shoes into the brake cylinder. Put the bottom of the shoes into the adjusters and use a small pair of vice grips to grab and install the bottom springs.
Easy; no?

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Scott McAdams
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Re: Rear Drum Brake Spring Location

#4 Post by Scott McAdams » Wed Jan 09, 2019 10:11 am

Erik and Vic. Thank you for the advice! I had a feeling the assymetry of that spring was violating the strict symmetry principals of those Porsche engineers... I will order a new spring to confirm that I am indeed working with the right part and then install it, knowing that I will probably make an offering of blood to the Brake Gods in the process of stretching that spring....
356B S90 Roadster, '60
Macan Turbo, '15
Cayenne, '08
C4S, '08
Targa, '84

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Vic Skirmants
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Joined: Tue Oct 27, 2009 5:02 pm
Location: SE Michigan

Re: Rear Drum Brake Spring Location

#5 Post by Vic Skirmants » Wed Jan 09, 2019 10:14 am

Scott McAdams wrote:Erik and Vic. Thank you for the advice! I had a feeling the assymetry of that spring was violating the strict symmetry principals of those Porsche engineers... I will order a new spring to confirm that I am indeed working with the right part and then install it, knowing that I will probably make an offering of blood to the Brake Gods in the process of stretching that spring....
As I said above; no need for brute force. No blood.

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Scott McAdams
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Joined: Thu Aug 28, 2014 9:59 am
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Location: San Juan Island

Re: Rear Drum Brake Spring Location

#6 Post by Scott McAdams » Wed Jan 09, 2019 10:22 am

Vic, Yeah, I see the beauty in your technique and might go with it. I’ll see how ambitious I am feeling and how tight that new spring is when I get it.
356B S90 Roadster, '60
Macan Turbo, '15
Cayenne, '08
C4S, '08
Targa, '84

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Jim Karaba
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Location: Lafayette, LA

Re: Rear Drum Brake Spring Location

#7 Post by Jim Karaba » Sat Jan 12, 2019 11:41 pm

Yup, I do like Vic says and install the bottom springs last, its easier and much faster.

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