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Emergency Brake Pivot Question 356C

Posted: Sat Dec 29, 2018 10:56 am
by Bill Waite
I am installing the emergency brake handle, guide tube, pivot bar, etc in our 356C coupe.

Each end of the pivot bar requires a bushing (the Katalog calls it a "bush") to enable proper operation. In the Katalog diagram (copy below) the one of the left side is identified as #20 with part number 644-24-207. I no longer have these bushings (my own fault). Unless I am missing something, I have been unable to find a source for these. If that is the case, I'll have to figure out a suitable replacement, maybe using a correctly sized bronze bushing (?). However, I believe the original bushings were actually plastic, but I may be wrong.

I'd appreciate any guidance / suggestions on this subject.

Re: Emergency Brake Pivot Question 356C

Posted: Sat Dec 29, 2018 1:03 pm
by Mike Wilson
That part is NLA. People have made substitutes. Sorry I don't have the dimensions but likely sources for bushing material would be Metric MultiStandard, Belmetric and pssibly McMaster Carr.

Mikr

Re: Emergency Brake Pivot Question 356C

Posted: Sat Dec 29, 2018 1:18 pm
by Hugo Karasawa
Those are plastic bushings. It is possible to fabricate those with a lathe.
Take part 21 and 19 to a machine shop and they can machine you the bushing.

Re: Emergency Brake Pivot Question 356C

Posted: Sat Dec 29, 2018 3:29 pm
by Mike Wilson
If you do take the parts to a machine shop, have them make several so you can repair yours and sell some to recoup your costs.

Mike

Re: Emergency Brake Pivot Question 356C

Posted: Sat Dec 29, 2018 4:31 pm
by Eric McKinley
Bill,

Read this, I got a set produced in bronze to the dimensions I placed on the thread,

They fit perfectly.

viewtopic.php?f=1&t=42568

Re: Emergency Brake Pivot Question 356C

Posted: Sat Dec 29, 2018 8:23 pm
by Bill Waite
My thanks to everyone who replied. Eric: before I posted this thread, I did a Forum search using the words "Emergency Brake Pivot" and unfortunately your posting re. the work you did on your system did not show up in the results. If it had... I wouldn't have had to ask the question. I will do a thorough web search to see if I can find anyone listing the proper size, which I am also posting here in the event someone looks at this thread for that info:

Per Eric McKinley, the proper size busing is as follows: The outside diameter: 17mm / inside diameter: 14mm / length: 16mm.

In any event, I will post the results and whatever I end up finding and/or doing.

Re: Emergency Brake Pivot Question 356C

Posted: Sun Dec 30, 2018 5:28 am
by Eric McKinley
Glad it helped Bill,

Re: Emergency Brake Pivot Question 356C

Posted: Mon Dec 31, 2018 9:19 am
by Mike Smith
`A` Bushings were steel - Later bushings were Nylon/Plastic

I have no idea when this change took place

Re: Emergency Brake Pivot Question 356C

Posted: Wed Jan 09, 2019 10:10 pm
by Bill Waite
My solution (at least for now) was the following:

After a lengthy online search I was pretty convinced that no one offered the ideal size bronze bushing (machine shop would be required). I converted Eric McKinley's ideal size in mm (OD = 17mm / ID =14mm / Length = 16mm) into inches: OD = .67", ID = .55" and length = .63".

I headed to my local ACE hardware and found white nylon bushings in the "nuts and bolts" aisle this size: OD = 5/8", ID = 1/2" and length = 5/8" or OD = .63", ID = .50" and length = .63". So, ideally the ID would have been a bit larger, as well as the OD.

The good news: nylon is inherently a bit "flexible". When I carefully (slowly) press fit them on the shafts (one in a vice and the other with a hard rubber hammer) they "expanded." I used a bit of white lithium grease on the shaft. If you look at the naked shafts you will see that they have a "taper" (smaller on the end than the inboard side). The nylon bushings more or less conformed to that taper. That is noticable in one of the photos below.

I don't know how these will stand the "test of time" but the fit was perfect. I applied a bit of white grease to bushings and the fit when mounted was snug but loose enough to move freely. Total cost = about $3.75. Photos below.
EBRAKE PIVOT SLEEVE.jpg
EBRAKE PIVOT SLEEVE 2.jpg
EBRAKE PIVOT SLEEVE 3.jpg

Re: Emergency Brake Pivot Question 356C

Posted: Wed Jan 09, 2019 11:07 pm
by Doug McDonnell
Paul Hatfield has nothing on you Bill. Beautiful.

Re: Emergency Brake Pivot Question 356C

Posted: Thu Jan 10, 2019 12:19 am
by Bill Waite
Thanks, Doug.. but, you know the only thing I share with Paul is our attention to detail. He is miles ahead of me when it comes to all things Porsche and his contributions to the 356 community. It is great to have his input and counsel as we work on our "twin" '65 Irish Green / Fawn coupes!

Re: Emergency Brake Pivot Question 356C

Posted: Thu Jan 10, 2019 11:51 am
by JERRY LANDES
Thanks so much Bill. I made the mistake of powder coating a number of the arms and they returned with the bushings burned out. So anyone reading this (NEVER POWDER COAT THIS PART!)

Re: Emergency Brake Pivot Question 356C

Posted: Thu Jan 10, 2019 12:32 pm
by Bill Waite
Jerry... I did the same thing with the main pivot mechanism. It was powder coated and I forget to mention (above) that I wire wheeled away all of the powder coating on the shaft (getting down to bare metal). I also cleaned off the paint that was on the other "fixed" shaft attached to the front beam adjuster.

In retrospect, if anyone is doing a lot of powder coating they should use the high temp silicone plugs and caps to protect threaded holes or shafts like this, etc. Had I used a right sized cap, powder coating would have no impact on the shaft. These plugs and caps are also useful for media blasting in areas that should remain as is.

Kits of assorted plugs and caps are available from many sources, such as:

https://www.amazon.com/High-Temp-Silico ... s=silicone