Home  |  Forums  |  914 Info  |  Blogs
 
914World.com - The fastest growing online 914 community!
 
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG. This site is not affiliated with Porsche in any way.
Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners.
 

Welcome Guest ( Log In | Register )

 
Reply to this topicStart new topic
> rear caliper piston, not winding back on
JFG
post Oct 15 2017, 09:08 AM
Post #1


Senior Member
***

Group: Members
Posts: 686
Joined: 7-April 16
From: Wales
Member No.: 19,869
Region Association: None



I started the refurb of my rear calipers today. i tested it before stripping and the hand brake piston worked as it should.

I watched the pmb youtube video and stripped the caliper but did not remove the handbrake mechanism. The easy side was refurbed first and all is good there.

When i tried to reassemble the hand brake side i cannot get the piston to wind back on. I've tried lots of ways but no joy. So i checked the threads and both seem ok except for a small notch inside the piston itself (see pic)

When i checked the threaded part inside the piston i can turn it quite freely, so trying to wind a bolt into it won't happen as there is no resistance.

Any ideas? Is the mechanism inside the piston knackered?

Attached Image

Attached Image
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
mobymutt
post Oct 15 2017, 05:19 PM
Post #2


Senior Member
***

Group: Members
Posts: 548
Joined: 16-December 13
From: Kingston, Ontario, Canada
Member No.: 16,770
Region Association: Canada



I'm sure others can give you a better answer, but since nobody else has chimed in yet...

I don't recall that interior bit being free to spin.

I suggest taking the piston apart per the PMB video, cleaning it up, and putting it back together. Maybe if it was put together wrong, reassembling it correctly might solve the problem.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
cary
post Oct 16 2017, 07:50 AM
Post #3


Advanced Member
****

Group: Members
Posts: 3,900
Joined: 26-January 04
From: Sherwood Oregon
Member No.: 1,608
Region Association: Pacific Northwest



Ditto on watching the PMB video. I just watched the pertinent section for a refresh.

Counterclockwise. While pressing on the piston with the other hand.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
JFG
post Oct 16 2017, 12:02 PM
Post #4


Senior Member
***

Group: Members
Posts: 686
Joined: 7-April 16
From: Wales
Member No.: 19,869
Region Association: None



I've emailed pmb for bits as i think the thread is damaged and just won't allow the winding to start.

User is offlineProfile CardPM
Go to the top of the page
+Quote Post
McMark
post Oct 17 2017, 07:00 AM
Post #5


914 Freak!
***************

Group: Retired Admin
Posts: 20,177
Joined: 13-March 03
From: Grand Rapids, MI
Member No.: 419
Region Association: None



The entire assembly inside the piston is removable. At least on the early pistons the assembly pops out intact. I'm not 100% sure on the late style you have, but I am sure it comes out. I'm also sure that a competent machine shop would be able to fix those threads for you. Could be as simple as running a tap through them to clean up any deformations. The threads don't carry any load, so there's no real danger of 'weakening'.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post

Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



- Lo-Fi Version Time is now: 28th March 2024 - 10:42 PM