Hello! Log in or Register   |  Help  |  Donate  |  Buy Shirts See all banner ads | Advertise on TheSamba.com  
TheSamba.com
 
1967 dual circuit MC reconditioning - but how can this work?
Forum Index -> Split Bus Share: Facebook Twitter
Reply to topic
Print View
Quick sort: Show newest posts on top | Show oldest posts on top View previous topic :: View next topic  
Author Message
Peter - Belgium
Samba Member


Joined: December 22, 2003
Posts: 760
Location: Brussels - Belgium
Peter - Belgium is offline 

PostPosted: Mon Jan 11, 2021 12:46 am    Post subject: 1967 dual circuit MC reconditioning - but how can this work? Reply with quote

Hello all,

I took apart a 67dual circuit MC and cleaned all + reassembled but when fitted to the bus I saw 2 issues:
1/ no oil reached the rear cilinders (not expected)
2/ some oil leaking out from the front of the pump (expected)

when I took it apart again and mocking up where the seals end i wonder how oil can actually get behind this one to be pushed to the rear wheels. The seal seems to be right below the oil passages not allowing oil to flow?
Image may have been reduced in size. Click image to view fullscreen.


Image may have been reduced in size. Click image to view fullscreen.


As for teh leak at the front of the MC, that seal is really worn. Any idea if there is a source for these seals? Tthe others could do with a replace as well I'm sure:
Image may have been reduced in size. Click image to view fullscreen.

Or any other - cheap - MC I can take these out from?

Thanks!
Peter
_________________
356 Outlaw built: https://www.thesamba.com/vw/forum/viewtopic.php?t=430774&highlight=
Back to top
View user's profile Send private message Send e-mail Visit poster's website Gallery Classifieds Feedback
ToolBox
Samba Member


Joined: January 27, 2004
Posts: 3439
Location: Detroit, where they don't jack parts off my ride in the parking lot of the 7-11
ToolBox is offline 

PostPosted: Mon Jan 11, 2021 10:50 am    Post subject: Re: 1967 dual circuit MC reconditioning - but how can this work? Reply with quote

Do you have a local seal house in your area? I work on brake test machines and our masters are much larger. I use a local seal warehouse to get replacements when needed.

The fluid flows through the body and pistons through machined passages. There is a cutaway in the Bentley that shows it.
Back to top
View user's profile Send private message Send e-mail AIM Address Gallery Classifieds Feedback
Alan Brase
Samba Member


Joined: March 28, 2004
Posts: 4532
Location: Cedar Falls, Iowa
Alan Brase is offline 

PostPosted: Mon Jan 11, 2021 4:37 pm    Post subject: Re: 1967 dual circuit MC reconditioning - but how can this work? Reply with quote

Wow, you just need to purchase a repair kit for a 1967 cylinder. I suppose the individual parts are available, but a kit will have new pistons in it as well as the brass check valves.
_________________
Al Brase
Projects: 67 sunroof bug, 67 Porsche 912 Targa, 70 Westy
Dec 1955 Single Cab pickup WANT 15" BUS RIMS dated 8/55, thru 12/55
To New owners: 1969 doublecab, 1971 Dormobile
Vanagons:
80 P27 Westy JUL 1979, 3rd oldest known US
83 1.6TD Vanagon, 87 Wolfie Westy daily driver, swap meet home
Back to top
View user's profile Send private message Send e-mail Gallery Classifieds Feedback
ToolBox
Samba Member


Joined: January 27, 2004
Posts: 3439
Location: Detroit, where they don't jack parts off my ride in the parking lot of the 7-11
ToolBox is offline 

PostPosted: Tue Jan 12, 2021 10:25 am    Post subject: Re: 1967 dual circuit MC reconditioning - but how can this work? Reply with quote

Alan Brase wrote:
Wow, you just need to purchase a repair kit for a 1967 cylinder. I suppose the individual parts are available, but a kit will have new pistons in it as well as the brass check valves.


I was unable to find a good rebuild kit a few years ago when I wanted one. Just bought a new master. All that I found had bad seals from sitting on the shelf for years.

But now this is my goto for seals and packing... https://www.zatkoff.com/catalog/master-catalog/molded-packings-piston-seals
Back to top
View user's profile Send private message Send e-mail AIM Address Gallery Classifieds Feedback
Alan Brase
Samba Member


Joined: March 28, 2004
Posts: 4532
Location: Cedar Falls, Iowa
Alan Brase is offline 

PostPosted: Thu Jan 14, 2021 11:44 pm    Post subject: Re: 1967 dual circuit MC reconditioning - but how can this work? Reply with quote

Well, now it comes up, I don't see any listed either in regular aftermarket sources.
I, too will need to find a 1967 master cylinder kit.
_________________
Al Brase
Projects: 67 sunroof bug, 67 Porsche 912 Targa, 70 Westy
Dec 1955 Single Cab pickup WANT 15" BUS RIMS dated 8/55, thru 12/55
To New owners: 1969 doublecab, 1971 Dormobile
Vanagons:
80 P27 Westy JUL 1979, 3rd oldest known US
83 1.6TD Vanagon, 87 Wolfie Westy daily driver, swap meet home
Back to top
View user's profile Send private message Send e-mail Gallery Classifieds Feedback
Peter - Belgium
Samba Member


Joined: December 22, 2003
Posts: 760
Location: Brussels - Belgium
Peter - Belgium is offline 

PostPosted: Fri Jan 15, 2021 12:56 am    Post subject: Re: 1967 dual circuit MC reconditioning - but how can this work? Reply with quote

Exactly... also never found a source for a rebuild kit, only complete master cilinders which are very expensive.

That is why most (including me sofar on all previous builts) always convert to the baywindow servo master to get to a dual circuit. Now I had an OG 67 master wanted to give that a try, but seems will need to convert again!

thanks!
_________________
356 Outlaw built: https://www.thesamba.com/vw/forum/viewtopic.php?t=430774&highlight=
Back to top
View user's profile Send private message Send e-mail Visit poster's website Gallery Classifieds Feedback
Tizian
Samba Member


Joined: February 18, 2015
Posts: 382
Location: Hamburg, Germany
Tizian is offline 

PostPosted: Fri Jan 15, 2021 1:46 am    Post subject: Re: 1967 dual circuit MC reconditioning - but how can this work? Reply with quote

Hi Peter,

I would suggest to buy a new MC. It’s you’re life insurance Wink and is still available from ATE. Just google it:

ATE 03.2122-0704.3

It’s not too expensive in my opinion...
Back to top
View user's profile Send private message Gallery Classifieds Feedback
flemcadiddlehopper
Samba Member


Joined: December 05, 2011
Posts: 2332
Location: Kelowna, BC. Canada.
flemcadiddlehopper is offline 

PostPosted: Sun Jan 17, 2021 6:26 pm    Post subject: Re: 1967 dual circuit MC reconditioning - but how can this work? Reply with quote

To answer your first question in the original post. The piston at rest should be just ahead of the fluid reservoir. The moment the piston begins to move it passes the hole there by pushing all fluid out the brake line port. When the piston returns it opens the reservoir port to allow fluid to flow in.
This is why pedal free play adjustment is so crucial. If the piston does not return and open that reservoir port, every application of the pedal will build up fluid pressure in that brake line until, it locks the brakes on.

And, just buy a new master cylinder....be able to stop is kinda important. It may be expensive, but it's cheaper than your bus and easier on you sole than killing a bus full of nuns and orphans.

Gordo.
_________________
Everybody Dies....Some Never Live.

Retrograde Garage. Vintage Aircooled, and others.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Display posts from previous:   
Reply to topic    Forum Index -> Split Bus 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 © 1996-2023, Everett Barnes. All Rights Reserved.
Not affiliated with or sponsored by Volkswagen of America | Forum powered by phpBB
Links to eBay or other vendor sites may be affiliate links where the site receives compensation.