 Brake Bleeding - Caliper Bizzaro |
|
|
|
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. |
|
|
  |
| tomeric914 |
 Apr 27 2014, 10:38 AM
Post
#1
|
|
One Lap of America in a 914!  Group: Members Posts: 1,268 Joined: 25-May 08 From: Syracuse, NY Member No.: 9,101 Region Association: North East States 
 |
Installed a complete new to me set of rebuilt calipers on a customer's 914. Master cylinder was recently replaced. Power bled the system with my Motiv bleeder set at 15 psi and couldn't get a good pedal. Did the traditional push/hold/release 2 person method and still couldn't get a good pedal.
If I wait about 10 seconds and then push the pedal hard, there is a hissing sound coming from the front. I thought it was the master cylinder at first but isolated it to the driver's front caliper. I've put close to 2 quarts through the system with absolutely no air. At my wits end, I put on the old caliper, bled it quick and the pedal is right where it needs to be. (IMG:style_emoticons/default/WTF.gif) I bled from the top bleeder, the bottom bleeder, as well as tried every trick I could think of. There are no leaks in the rebuilt caliper and yes it is a quality rebuild from PMB. I'll take apart the caliper and see what I find inside. Again, these are secondhand rebuilds so who knows what could be in there. If anyone has run across a similar to issue, let me know what you found! |
   |
 
|
| Mark Henry |
Apr 27 2014, 10:44 AM
Post
#2
|
|
that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
Did you try cracking each line connection and bleed it as if it was a bleed screw?
Yeh...I know it makes a hell of a mess...but in a pinch it often works. |
|
|
|
| tomeric914 |
Apr 27 2014, 10:46 AM
Post
#3
|
|
One Lap of America in a 914! Group: Members Posts: 1,268 Joined: 25-May 08 From: Syracuse, NY Member No.: 9,101 Region Association: North East States
|
QUOTE(Mark Henry @ Apr 27 2014, 11:44 AM)  Did you try cracking each line connection and bleed it as if it was a bleed screw? I'm pretty sure it's in the caliper. I put the old caliper back on and the pedal is right where it should be with no hissing from the front. |
|
|
|
| tomeric914 |
Apr 27 2014, 12:41 PM
Post
#4
|
|
One Lap of America in a 914! Group: Members Posts: 1,268 Joined: 25-May 08 From: Syracuse, NY Member No.: 9,101 Region Association: North East States
|
Found it. Blocked passage inside the caliper leading up to the top bleeder wouldn't allow the air out.
(IMG:style_emoticons/default/headbang.gif) |
|
|
|
| Eric_Shea |
Apr 27 2014, 11:38 PM
Post
#5
|
|
PMB Performance Group: Admin Posts: 19,304 Joined: 3-September 03 From: Salt Lake City, UT Member No.: 1,110 Region Association: Rocky Mountains  |
Happens sometimes, we call them caliper worms. When people mix DOT4 and 5.
Sometimes we see them when people tried to use grease to remove the pistons and didn't clean out the passages. Very hard to diagnose. |
|
|
|
|
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:
|
Lo-Fi Version | Time is now: 6th July 2025 - 05:27 AM |
Invision Power Board
v9.1.4 © 2025 IPS, Inc.