Vanagon EuroVan
Previous messageNext messagePrevious in topicNext in topicPrevious by same authorNext by same authorPrevious page (February 2005, week 4)Back to main VANAGON pageJoin or leave VANAGON (or change settings)ReplyPost a new messageSearchProportional fontNon-proportional font
Date:         Wed, 23 Feb 2005 00:57:24 -0500
Reply-To:     Jonathan Farrugia <jfarrugi@UMICH.EDU>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Jonathan Farrugia <jfarrugi@UMICH.EDU>
Subject:      How To: Clutch Master Cylinder
Content-Type: TEXT/PLAIN; charset=US-ASCII

How to Change a Vanagon Clutch Master Cylinder -----------------------------------------------

Use a small 2" C-clamp to gently pinch the supply hose closed. This is the hose that runs from the brake fluid reservoir to the top of the clutch master cylinder. Position the clamp a few inches from where the supply hose terminates onto the master cylinder. That keeps you from getting so much fluid every where and negates the need to drain or siphon brake fluid out of the reservoir. To bleed the remainder of the fluid out of the clutch master cylinder do the following. Grab some type of container and a section of hose to fit onto the clutch slave cylinder bleeder valve. Crawl under the back of the van, put your hose on the bleeder and place the end of your hose in your container. Now open the slave bleeder valve with your 7mm wrench and let the fluid out. In order to get all of the fluid out of the system you can head back up front and pump the clutch pedal a few times. Now it is time to actually get into taking the clutch master cylinder out. Before you crack any of the connections be sure to have a bunch of towels under the master so you don't get fluid on the carpet/paint.

Now you can crack the hydraulic line fitting that goes from the master to the slave. As you open the fitting take care to soak up the fluid with your rags or towels. Once the fitting is loosened and it has stopped draining for the most part you can move on to disconnecting the supply line from the brake fluid reservoir. The last step is to remove the two 13mm bolts that hold the master cylinder to the aluminum bracket. As an aid to reinstalling the master you may want to mark the location of the 13mm bolts before you loosen them since the bolt holes are slotted. Once those bolts are out you can slide the master down from the pin that engages in the top of the master.

To reinstall the new clutch master cylinder I recommend putting a small amount of grease in the top of the master cylinder where the clutch pedal push pin operates the cylinder. After that is done then you can reposition the master back in its place, making sure to slide the push pin into the bore in the top of the cylinder. If I remember correctly it is easiest to attach the hydraulic line to the slave first then after that reinstall the two 13mm bolts and the supply line from the brake fluid reservoir.

The best way to bleed the clutch is to crack the slave bleeder with a hose attached and the hose in a bottle or jar. Go fill up the reservoir and pump the pedal a bunch of times keeping the reservoir topped up. Now check the bottle, once a fair amount of fluid has been pushed out you can bleed the system as normal, with out worrying about a ton of air being in the system.

Now for some theory. You will often see that people end up replacing the slave shortly after they do the master. One possible cause for this is not cleaning the slave or flushing it adequately. As the master failed the failing seals allowed the aluminum piston to scrap against the bore of the master cylinder. This generated metal particles in the system, which accelerated wear on other parts of the system. So you need to get all that metal out or it will prematurely wear out the parts with the weakest link being your slave.

The best way to to this is to pull the slave while you are doing the job, take it apart, clean and lube it and reinstall it. If you are really anal/preventive, put some new seals in it. Before you reinstall it, install the master and pump some fluid through the system to clean the line out. If you don't pull and clean the slave cylinder, pump a lot of fluid through the system. If I don't pull the slave I pump at least one of the small bottles of brake fluid through the system as my flush. Brake fluid is cheap relative to the parts. Then I rebleed the system in a couple of weeks once all the parts have been moving around for a while. This is done to help remove any metal that you might not have been able to get out with the initial clean out bleeding.

jonathan


Back to: Top of message | Previous page | Main VANAGON page

Please note - During the past 17 years of operation, several gigabytes of Vanagon mail messages have been archived. Searching the entire collection will take up to five minutes to complete. Please be patient!


Return to the archives @ gerry.vanagon.com


The vanagon mailing list archives are copyright (c) 1994-2011, and may not be reproduced without the express written permission of the list administrators. Posting messages to this mailing list grants a license to the mailing list administrators to reproduce the message in a compilation, either printed or electronic. All compilations will be not-for-profit, with any excess proceeds going to the Vanagon mailing list.

Any profits from list compilations go exclusively towards the management and operation of the Vanagon mailing list and vanagon mailing list web site.