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 )

> Lost brake pressure temporarily?, where to start
jeremiah98125
post Feb 19 2010, 06:25 PM
Post #1


jr
*

Group: Members
Posts: 37
Joined: 11-November 09
From: seattle, wa
Member No.: 11,031
Region Association: Pacific Northwest
So I took my 1.7 out on it's maiden voyage today and having some issues with the brakes.. They worked okay for the first 10 miles, good pressure at the pedal but didn't really slow the car down all that great. Then all of a sudden I totally lost pressure and had to pump them about 5 or 6 times to regain the pressure. Kind of scary here in the city.. So I headed home pumping the brakes a bunch before every stop. As I started pulling into the yard the pressure came back and the felt fine again. And sitting in the yard they feel okay again.. It kind of seemed like a hose burst or something but I don't see any fluid dripping on ground and the level in the master cylinder hasn't dropped any. Any idea what happened and how to fix em? The last service report which was 1,000 miles & 12 years ago said "free up calipers, replace pads, repack bearings". Also, manual says use "J1703" brake fluid, what is that? thanks!!
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
 
 Reply to this topicStart new topic
Replies(1 - 13)
rick 918-S
post Feb 19 2010, 06:30 PM
Post #2


Hey nice rack! -Celette
***************

Group: Members
Posts: 20,473
Joined: 30-December 02
From: Now in Superior WI
Member No.: 43
Region Association: Northstar Region
Master cylinder died. That would be my guess.
User is online!Profile CardPM
Go to the top of the page
+Quote Post
yeahmag
post Feb 19 2010, 06:32 PM
Post #3


Advanced Member
****

Group: Members
Posts: 2,422
Joined: 18-April 05
From: Pasadena, CA
Member No.: 3,946
Region Association: Southern California
Agreed. Without any external leak your master cylinder is shot. Replace it before you drive it again.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
dr914@autoatlanta.com
post Feb 19 2010, 06:38 PM
Post #4


914 Guru
*****

Group: Members
Posts: 7,887
Joined: 3-January 07
From: atlanta georgia
Member No.: 7,418
Region Association: None


this is an easy one. The flex lines are clogged or a caliper piston is sticking causing the brakes to stick and boil the fluid losing pressure. As soon as the fluid cools the pedal is back to normal. Could also be a sticking brake pedal but I am sure that you checked that. Master cylinder is probably ok, and certainly not causing the problem you are experiencing.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
yeahmag
post Feb 19 2010, 06:39 PM
Post #5


Advanced Member
****

Group: Members
Posts: 2,422
Joined: 18-April 05
From: Pasadena, CA
Member No.: 3,946
Region Association: Southern California
Interesting take on that... I like it.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Dr. Roger
post Feb 19 2010, 06:42 PM
Post #6


A bat out of hell.
****

Group: Members
Posts: 3,944
Joined: 31-January 05
From: Hercules, California
Member No.: 3,533
Region Association: Northern California
MC for sure.

Also the pads are probably hardened to the point of losing their friction coefficient. Happened to me with similar time/mileage circumstances.

Just glad you didn't die. =)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
yeahmag
post Feb 19 2010, 06:44 PM
Post #7


Advanced Member
****

Group: Members
Posts: 2,422
Joined: 18-April 05
From: Pasadena, CA
Member No.: 3,946
Region Association: Southern California
Oh yeah... Replacing my old pads made a HUGE difference. You had to stand on the brakes to get the car to stop.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
jeremiah98125
post Feb 19 2010, 08:22 PM
Post #8


jr
*

Group: Members
Posts: 37
Joined: 11-November 09
From: seattle, wa
Member No.: 11,031
Region Association: Pacific Northwest
Thanks for the replies. Sounds like I'm gonna be checking out the whole brake system next week.. Any recommendations on what brake parts commonly need replacing? I like to have the new parts before I get into a job.. It's such a pain in the arse for me to work on anything down low on the car since I've only got a dirt/gravel yard to work in. I hope to use the car as a commuter so I want the brakes working awesome
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Dr. Roger
post Feb 19 2010, 08:44 PM
Post #9


A bat out of hell.
****

Group: Members
Posts: 3,944
Joined: 31-January 05
From: Hercules, California
Member No.: 3,533
Region Association: Northern California
i can't imagine any wheel cylinder or MC not being corroded and half locked up if not full locked up after that long.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
underthetire
post Feb 19 2010, 09:16 PM
Post #10


914 Guru
*****

Group: Members
Posts: 5,062
Joined: 7-October 08
From: Brentwood
Member No.: 9,623
Region Association: Northern California
If your gonna do it, call eric and get everything. rubber lines, caliper rebuilt kits at least for the front, some good pads then maybe a master.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
detoxcowboy
post Feb 19 2010, 09:19 PM
Post #11


Senior Member
***

Group: Members
Posts: 1,294
Joined: 30-January 08
Member No.: 8,642
Region Association: Africa
Brake Problems fixed first is the best idea, even if they work they should be freshly gone over if your the new owner.. You got home safe perfect, perfect first issue.. After this you will be able to stop the car no matter what goes wrong next,, or at least have confidence to do so..
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
jeremiah98125
post Feb 22 2010, 09:55 AM
Post #12


jr
*

Group: Members
Posts: 37
Joined: 11-November 09
From: seattle, wa
Member No.: 11,031
Region Association: Pacific Northwest
So I pulled off all the calipers, turns out both the rear calipers were dragging from sticky piston I assume.. Probably from sitting with the P brake on for so long.. The brake fluid was black like dirty engine oil. I flushed it out with new fluid and I'm going to work some more on them today and put in new pads.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Rav914
post Feb 22 2010, 11:04 AM
Post #13


All-weather fan
***

Group: Members
Posts: 738
Joined: 15-April 07
From: WA
Member No.: 7,669
Region Association: None
QUOTE(underthetire @ Feb 19 2010, 07:16 PM) *

If your gonna do it, call eric and get everything. rubber lines, caliper rebuilt kits at least for the front, some good pads then maybe a master.


(IMG:style_emoticons/default/agree.gif) Any 914 new to me is a complete brake job. Eric does the calipers, I change the lines, and a new MC is a must. Even if the car sits for some time while I collect the $. The ability to stop is more important than the power to go. Just imagine coming around a corner and some little kid is in the street.....
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
VaccaRabite
post Feb 22 2010, 11:37 AM
Post #14


En Garde!
**********

Group: Admin
Posts: 13,456
Joined: 15-December 03
From: Dallastown, PA
Member No.: 1,435
Region Association: MidAtlantic Region
Expect to need to replace the hard lines as well as the soft lines. I have yet to come across soft lines that are removable from the hard line connections w/o destruction - even with line wrenches.

Zach
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
« Next Oldest · 914World Garage · Next Newest »
 

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

 

Display Mode: Switch to: Standard · Linear+ · Switch to: Outline

Track this topic · Email this topic · Print this topic · Subscribe to this forum

- Lo-Fi Version Time is now: 2nd June 2024 - 12:58 PM
Invision Power Board v9.1.4 © 2024  IPS, Inc.
All rights reserved 914World.com © since 2002
914World.com is the fastest growing online 914 community!
We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ...