Hello! Log in or Register   |  Help  |  Donate  |  Buy Shirts See all banner ads | Advertise on TheSamba.com  
TheSamba.com
 
front brake calipers
Forum Index -> 411/412 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
titan3c
Samba Member


Joined: February 16, 2012
Posts: 568
Location: Coweta, Oklahoma
titan3c is offline 

PostPosted: Fri Jul 13, 2018 8:54 am    Post subject: front brake calipers Reply with quote

There has to be a previous forum on this, but I couldn't find it. Some years back I ordered and received front brake calipers(not loaded), and I received one identical to the original for a 71 411 with just one bleeding valve, the other one was a later model with two bleeding valves---upper and lower. I think it was from centric---anyhow after discussion with them they insisted that the two bleeder was for a 71 type 4, and no return possible. So I proceeded with installing the later model which went on the right front wheel. It seems to be working OK, but I've always wondered if there is something about it that's not OK.
Back to top
View user's profile Send private message Classifieds Feedback
raygreenwood
Samba Member


Joined: November 24, 2008
Posts: 21474
Location: Oklahoma City
raygreenwood is offline 

PostPosted: Fri Jul 13, 2018 9:13 am    Post subject: Re: front brake calipers Reply with quote

titan3c wrote:
There has to be a previous forum on this, but I couldn't find it. Some years back I ordered and received front brake calipers(not loaded), and I received one identical to the original for a 71 411 with just one bleeding valve, the other one was a later model with two bleeding valves---upper and lower. I think it was from centric---anyhow after discussion with them they insisted that the two bleeder was for a 71 type 4, and no return possible. So I proceeded with installing the later model which went on the right front wheel. It seems to be working OK, but I've always wondered if there is something about it that's not OK.


Much like they did on the bus and type 3 cars....the early cars had a single bleeder valve. Since the bleeder valve you are going to use to bleed with must be on the top of the caliper because the air bubbles float upward....that meant that they would then have to stock two totally different part #'s that are actually made from the same casting mold. One for teh right and one for the left.

They got smart and simply installed two bleeder valves on the later calipers so the same part # can be used on the right and the left.

Also if you are draining the system down right before doing heavy maintenance...having the lower bleeder valve is useful. You can crack both bleeders open and pull the cap off the reservoir and it drains faster.

Another benefit that I have seen over the years that many people miss....is that when you bleed the calipers...and you only use the top bleeder...people think that every scrap or drop of the brake fluid in the lower part of the caliper magically just gets in line an exits because you are opening the top bleeder valve.

This is not true....especially in a system that has sat for a while. Once fluid gets saturated with water and starts allowing some individual droplets and rust to form....this sediment tends to stay in the bottom end and does not get fully bled out when you do not have a bottom bleeder. This is one of the prime causes of internal rust in the bottom area of a caliper that sits for a long time.

You can largely keep this at bay on a single bleeder caliper by just changing out fluid every 2 years...or when you are bleeding the system...unbolt the caliper for a minute and tip it over.

But the single bleeder or double bleeder calipers will work just fine

This same issue is a problem on many modern brake and hydraulic clutch systems. For instance on the Mk5 and Mk6 jetta and golf.....and really even on the 411/412 to a smaller extent ...the hydraulic clutch slave is a dead end system with the inlet almost dead center in the back of it....and the bleeder valve is right next to the inlet.....and on the Jetta/golf....the slave cylinder is about 4" long.....so the fresh fluid you are pumping in during bleeding.....will take the path of least resistance and distance....and go straight out the bleeder valve....and not sweep any of the old fluid that is in the 4" long cylinder with it. The water and residue soaked fluid stays in the cylinder and is bad for the seals.
So.... many have found that after a few bleedings over the years....when they then take a hand pump and small bore tube tube run through the fluid or bleeder inlet into the slave...and suck out whats in their....they get black watery gunk. Ray
Back to top
View user's profile Send private message Send e-mail Gallery Classifieds Feedback
titan3c
Samba Member


Joined: February 16, 2012
Posts: 568
Location: Coweta, Oklahoma
titan3c is offline 

PostPosted: Fri Jul 13, 2018 1:47 pm    Post subject: Re: front brake calipers Reply with quote

Ok----then the two bleeder calipers will fit and actually are better---right? I think I will replace the one bleeder with a two bleeder caliper. Bob
Back to top
View user's profile Send private message Classifieds Feedback
Display posts from previous:   
Reply to topic    Forum Index -> 411/412 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.