Hello! Log in or Register   |  Help  |  Donate  |  Buy Shirts  See all banner ads | Advertise on TheSamba.com  
TheSamba.com
 
Leaking brake light switch on 1970 VW Bug master cylinder
Forum Index -> Beetle - Late Model/Super - 1968-up Share: Facebook Twitter
Reply to topic
Print View
View previous topic :: View next topic  
Author Message
DocErickson
Samba Member


Joined: June 08, 2010
Posts: 3
Location: Virginia
DocErickson is offline 

PostPosted: Tue Jun 08, 2010 6:36 pm    Post subject: Leaking brake light switch on 1970 VW Bug master cylinder Reply with quote

So, I just installed a new master cylinder (Brazilian, not German) and did all the things you are supposed to do (bench bled, adjusted brakes, remove drums to check slave cylinders...etc.) and the front brake light switch is leaking. I cranked down on it as hard as I could and it's still leaking. I tried replacing it with the old one and it still leaks. That leads me to one of two conclusions. The MC is trash or the I misadjusted the push rod and it's going down too far, but I'm pretty sure I adjusted it right. Should I replace the master cylinder again or is it the push rod adjustment that I messed up?

Thanks for your help.
Back to top
View user's profile Send private message Classifieds Feedback
dakdak
Samba Member


Joined: March 09, 2009
Posts: 578
Location: Sydney, Australia
dakdak is offline 

PostPosted: Tue Jun 08, 2010 6:43 pm    Post subject: Re: Leaking brake light switch on 1970 VW Bug master cylinde Reply with quote

DocErickson wrote:
So, I just installed a new master cylinder (Brazilian, not German) and did all the things you are supposed to do (bench bled, adjusted brakes, remove drums to check slave cylinders...etc.) and the front brake light switch is leaking. I cranked down on it as hard as I could and it's still leaking. I tried replacing it with the old one and it still leaks. That leads me to one of two conclusions. The MC is trash or the I misadjusted the push rod and it's going down too far, but I'm pretty sure I adjusted it right. Should I replace the master cylinder again or is it the push rod adjustment that I messed up?

Thanks for your help.


When you say you "cranked down" as hard as you could, it is possible you may have craked the master cylinder at the threads. Check the master cylinder around the brake light switch threads for any cracking. If you're satisfied it's not cracked, you may try using the white teflon thread tape on the switch threads and see if it still leaks. This may draw some criticism, but if it works, it works.
_________________
The great enemy of the truth is very often not the lie - deliberate, contrived and dishonest, but the myth - persistent, persuasive and unrealistic.

JFK
Back to top
View user's profile Send private message Gallery Classifieds Feedback
DocErickson
Samba Member


Joined: June 08, 2010
Posts: 3
Location: Virginia
DocErickson is offline 

PostPosted: Tue Jun 08, 2010 6:47 pm    Post subject: Reply with quote

I had it pretty snug to begin with, saw that it was leaking when my assistant was pushing on the brakes, so I gave it another quarter turn, and I'm no Hercules, so I'm pretty sure I didn't crank it too hard. I'll try the dope tape method.
Back to top
View user's profile Send private message Classifieds Feedback
69 Jim
Samba Member


Joined: September 27, 2004
Posts: 6688
Location: Chickengeorge's Neighbor
69 Jim is offline 

PostPosted: Tue Jun 08, 2010 7:44 pm    Post subject: Reply with quote

Not a good idea to trust your life on a garbage Brazil made master.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
DocErickson
Samba Member


Joined: June 08, 2010
Posts: 3
Location: Virginia
DocErickson is offline 

PostPosted: Wed Jun 09, 2010 5:17 pm    Post subject: Reply with quote

After all was said and done, I replaced the brake light switch with genuine German switches with high temp thread sealer, and it's holding up as of right now. Now I have to wait for my assistant to help me bleed my brakes.
Back to top
View user's profile Send private message Classifieds Feedback
johneliot
Samba Member


Joined: August 29, 2005
Posts: 1792
Location: Chico, CA
johneliot is offline 

PostPosted: Wed Jun 09, 2010 11:30 pm    Post subject: Reply with quote

I had exactly the same problem with my 69. I decided to go cheaper with the MC (i was a Varga I believe). No amount to tightening would stop th leak. I decided to eat the $25 and buy a German one and it never leaked again. You should not have to use any type of sealer on the switches. Brake fluid eats paint in no time, I can't imagine what it would do to teflon tape.
_________________
John

There is no distinctly American criminal class - except Congress.
Mark Twain
Back to top
View user's profile Send private message Gallery Classifieds Feedback
69 Jim
Samba Member


Joined: September 27, 2004
Posts: 6688
Location: Chickengeorge's Neighbor
69 Jim is offline 

PostPosted: Thu Jun 10, 2010 12:06 am    Post subject: Reply with quote

My switches came with brown loctite on them.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Cusser
Samba Member


Joined: October 02, 2006
Posts: 11818
Location: Hot Arizona
Cusser is offline 

PostPosted: Thu Jun 10, 2010 6:28 am    Post subject: Reply with quote

johneliot wrote:
You should not have to use any type of sealer on the switches.


Agree.

johneliot wrote:
Brake fluid eats paint in no time, I can't imagine what it would do to teflon tape.


Teflon (polytetrafluoroethane or PTFE) won't dissolve in brake fluid, or most anything.
_________________
1970 VW (owned since 1972) and 1971 VW Convertible (owned since 1976), second owner of each. The '71 now has the 1835 engine, swapped from the '70. Second owner of each. 1988 Mazda B2200 truck, 1998 Frontier, 2004 Yukon, 2004 Frontier King Cab. All manual transmission except for the Yukon. http://www.thesamba.com/vw/forum/album_page.php?pic_id=335294 http://www.thesamba.com/vw/forum/album_page.php?pic_id=335297
Back to top
View user's profile Send private message Gallery Classifieds Feedback
bogrady
Samba Member


Joined: November 08, 2009
Posts: 7
Location: Colorado
bogrady is offline 

PostPosted: Mon Dec 13, 2010 10:30 am    Post subject: Reply with quote

Where did you purchase your part from? I am having the same problem and need to know the best/cheapest place to get it.

Thanks!
Back to top
View user's profile Send private message Classifieds Feedback
JonF
Samba Member


Joined: December 16, 2005
Posts: 2078
Location: Oklahoma
JonF is offline 

PostPosted: Mon Dec 13, 2010 11:35 am    Post subject: Reply with quote

i had a prob over the summer with brake light switches also! there was a bad batch of switches made and i had to replace the switches 3 times before i got 2 good switches.

Image may have been reduced in size. Click image to view fullscreen.
_________________
68 bug 1600sp 30/31
68 baja 1600sp 010 32ndix
Back to top
View user's profile Send private message Facebook Classifieds Feedback
marcodelat
Samba Member


Joined: December 10, 2007
Posts: 107
Location: Key Largo, Florida
marcodelat is offline 

PostPosted: Mon Dec 13, 2010 12:44 pm    Post subject: Reply with quote

DocErickson wrote:
... Now I have to wait for my assistant to help me bleed my brakes.

While you are waiting... let gravity be "your assistant"... in other words try gravity bleeding - do a search here or on the net.
Back to top
View user's profile Send private message Classifieds Feedback
velvetguru
Samba Member


Joined: December 11, 2010
Posts: 18
Location: Owasso, OK
velvetguru is offline 

PostPosted: Thu Dec 16, 2010 10:12 pm    Post subject: Reply with quote

Why not just rebuild your original German made master cylinder. A kit is inexpensive and easy to install, it's just a few rubber parts and a spring. You have the advantage of keeping the car original and you don't have to deal with all these new 'just as good as the original' junk parts being made today. Just my two cents.

Joe
Back to top
View user's profile Send private message Classifieds Feedback
rtaylor
Samba Member


Joined: November 08, 2010
Posts: 361
Location: Camden, NC
rtaylor is offline 

PostPosted: Thu Jan 06, 2011 4:18 pm    Post subject: Reply with quote

if anyones still checking this post, it has been a while since it was posted, butt im having the same problem with my brake switches. ive gone through litterally 8. autozone has replaced them everything since they have a warranty. buttt im gettin tired of buying brake fluid and having to bleed my brakes. soo any idea of a better palce i can go? i just ordered some from napa.....but if they ont work i need a back up plan
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Display posts from previous:   
Reply to topic    Forum Index -> Beetle - Late Model/Super - 1968-up All times are Mountain Standard Time/Pacific Daylight Savings Time
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum

About | Help! | Advertise | Donate | Premium Membership | Privacy/Terms of Use | Contact Us | Site Map
Copyright © 1996-2013, Everett Barnes. All Rights Reserved.
Not affiliated with or sponsored by Volkswagen of America | Forum powered by phpBB