Camp Westfalia

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Vanagon Clutch Slave Cylinder Replacement

Related Topics:

Hydraulic Clutch System Overview
Clutch Master Cylinder Replacement
Bleeding the Clutch Hydraulic System

Vanagon Clutch Slave Cylinder

  1. Back in the left-forward corner of the engine compartment, just ahead of the edge of the deck-lid opening, you will find the clutch slave cylinder mounted to the clutch housing. Start by using some WD-40 and a shop rag to clean loose crud from the area, especially around the union nut on the steel high-pressure line entering the front of the slave cylinder. The introduction of dirt or other crud into your hydraulic system here or anywhere else will soon mean trouble. When clean, loosen but do not completely remove the union nut.
  2. Loosen the two retaining bolts attaching the slave cylinder to its mounting bracket. If yours are rusted and seized, and the penetrating oil hasn’t worked, you may need to use the propane torch to carefully apply some heat to them. NOTE: be very careful to not damage nearby wires or coolant hoses.
    Use an open-end wrench to hold the bolt heads from beneath the bracket, while using a socket and ratchet to loosen the nuts from above. Alternatively, you may find you have better access while lying beneath the van.
    Completely detach the high-pressure line from the slave cylinder, and withdraw the entire slave cylinder from its bracket.
  3. If your old mounting bolts are rusty and corroded, replace them with new M8x25 bolts and nuts. Before dropping the new slave cylinder into place, you’ll want to be sure the rearmost (closest to you) mounting bolt is safely installed in its hole, as it will be impossible to get it in once the slave cylinder is in place. If necessary, prevent the bolt from falling out by temporarily threading its nut onto it.
  4. Vanagon Clutch Slave Cylinder

  5. Put a dab of general-purpose grease into the small cup at the end of the slave cylinder actuator, to lubricate the ball on the clutch-engagement lever to which it will connect. Set the slave cylinder into place, making sure the cup engages the ball (it doesn’t need to ‘snap’ into place, but simply engage), and slip the slave cylinder over its mounting bolts (having previously removed the temporary nut from the rearmost mounting bolt). Loosely thread the nuts onto the mounting bolts but do not tighten yet.
  6. Start threading the pressure fitting into the slave cylinder by hand, then finish by wrench-tightening to 12 ft./lbs.. Tighten the mounting nuts to to 18 ft./lbs..


Once everything is satisfactorily reconnected, proceed to Bleeding the Vanagon Clutch Hydraulic System.

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Bleeding the Vanagon Clutch Hydraulic System

Related Topics:

Hydraulic Clutch System Overview
Clutch Master Cylinder Replacement
Clutch Slave Cylinder Replacement

Vacuum bleeder pumpAfter replacing any clutch hydraulic components, air will have been introduced into the system, and this will prevent proper functioning of the clutch mechanism, so it must be bled. Start by carefully topping-up the fluid reservoir in the dash with fresh fluid. Unlike the brake hydraulic system, the clutch evidently cannot be bled simply by pumping the pedal; the air bubbles will only compress and expand instead of being forced out, so Volkswagen specifies that a vacuum-pump-actuated bleeder be used. The Haynes manual states one CAN use the usual bleeding techniques, so who knows? I’m also told that one can simply leave the rear of the van raised and the bleeder screw left open overnight, allowing air bubbles to work themselves out, but I have not tried this method, and remain dubious.

I purchased a vacuum bleeder pump kit which can be used for both clutch & brake hydraulic systems, as well as testing vacuum hoses.

  1. Atop the slave cylinder is a bleeder screw, protected by the rubber dust cap. Remove the cap, loosen the screw 1/2 turn, and attach the hose of the vacuum bleeder, according to the bleeder kit’s instructions.
  2. Actuate the bleeder pump several times, until fluid begins to flow through the tubing and into the bleeding reservoir. NOTE: If the hydraulic fluid has not been changed in recent years, it will be dark or nearly black, indicating contamination by dirt and water; this is perhaps what caused your components to fail in the first place. Volkswagen (and most other auto manufacturers, for that matter) recommends brake/clutch fluid be replaced every two years, as outlined here.
  3. Continue drawing fluid until it is clear of dirt, moisture, and air bubbles, periodically pausing to check the level in the dash reservoir and adding fresh fluid if necessary. Do not allow this level to fall below the ‘MIN’ indicator, or air will again be introduced into the system, and you will have to start bleeding all over again.
    Remember, you’ve got about 10 feet of 3-4mm line to bleed, so this may take a full 12 oz. bottle or more.
  4. When satisfied all the air has been bled from the system, tighten the slave cylinder bleeder and replace the dust cap. Fire up the engine and see if you can engage/disengage the transmission. If the gears clash or refuse to engage, you probably still have air in the line; re-bleed and try again. If all seems well, drive down off the ramps and take her out on the road to run through all the gears. You may find that within a couple hundred miles of driving over the next few weeks, the gears will begin to complain. This probably means you still have some air bubbles lurking in your line, so bleed again until it works right.

Check with your local municipality regarding the proper disposal of your used brake fluid. Mine requested that I add it right to my used motor oil and recycle it all together. Others may prefer that you keep the brake fluid separate from other automotive fluids and dispose of it as a hazardous material.

Even if you have failed during this process to keep the fluid level in the reservoir topped-up, as long as you haven’t depressed the brake pedal air should not have been introduced into the braking system, so the brakes will not need to be bled. However, if the fluid is more than two years old, and since you’ve already gotten your tools dirty and probably stained your pants, now would be a good time to bleed your brakes.

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Vanagon Clutch Master Cylinder Replacement

Related Topics:

Hydraulic Clutch System Overview
Clutch Slave Cylinder Replacement
Bleeding the Clutch Hydraulic System

Vanagon Clutch Master & Slave CylindersBefore getting started, check out the “Vanagon Hydraulic Clutch System Overview”

  1. Start with some vigorous stretching exercises and calisthenics as taught by your junior high school Phys. Ed. coach; the clutch master cylinder in particular is very well tucked away beneath the dash and there is no comfortable way to work on it without assuming a variety of contorted postures and compromising positions.
  2. I suggest you use ramps or jackstands to raise the rear of the Vanagon. This will later encourage the inevitable air bubbles in the hydraulic line to migrate back to the slave cylinder, where they can easily be bled out. Set the parking brake and engage the transmission in reverse or first gear.
  3. Remove the shroud covering the instrument cluster, to gain access to the hydraulic fluid reservoir. Also remove the lower steering-column cover by removing the two screws and carefully working it loose.
  4. Vanagon Clutch Pedal

  5. Lay down your plastic sheeting and tape it snugly around the base of the steering column. Hydraulic fluid will infiltrate carpeting and dissolve paint, so do all you can to prevent it getting on painted bodywork. Use cold water or rubbing alcohol to clean any spills.
  6. The hydraulic reservoir contains several ounces of fluid, and if you simply disconnect the braided rubber supply hose leading to the clutch master cylinder, about half of this fluid will drain out and onto the floor, so have a catch can ready. Or either use a turkey baster to remove enough fluid so that the level falls below the supply hose outlet, or use hose-clamping tool to gently pinch off the supply hose. Then carefully wriggle the hose loose from its plastic nipple on the master cylinder.
  7. From your new or old slave cylinder, borrow the rubber dust cap for the bleeder screw and keep it handy. Begin loosening the pressure fitting on the metal high-pressure line exiting the back of the master cylinder, then remove the two retaining bolts which hold the master cylinder to its bracket.
  8. Vanagon Clutch Master Cylinder

  9. Completely remove the metal line from the master cylinder. To prevent several ounces of hydraulic fluid from dribbling onto the floor, temporarily slip that rubber dust cap over the end of the line. By pinching off the rubber supply hose, and plugging the end of the metal line, you should have no more than a tablespoonful or so of hydraulic fluid to clean up. NOTE: Vanagons built prior to 1987 utilize a union-nut pressure fitting for this application, while later models use a bolt-through banjo fitting with two copper washers. If yours uses the latter style, be sure to replace these washers when re-installing.
  10. Carefully lower the master cylinder from its place, being mindful of the pedal-actuated rod which will slip from the rubber boot atop the master cylinder.
  11. Installation of your shiny new master cylinder is pretty much the reverse of removal, starting by carefully slipping the actuator rod into the master cylinder’s rubber boot. After removing the rubber dust cap from the end of the metal line, you may find it easier to start threading the high-pressure union into the master cylinder if you do so before mounting the master cylinder. Tighten the master cylinder’s mounting bolts to 18 ft./lbs, and the high-pressure line fitting to 12 ft./lbs..

Once everything is satisfactorily reconnected, you can either proceed to “Vanagon Clutch Slave Cylinder Replacement” or, if not doing so, skip ahead to Bleeding the Vanagon Clutch Hydraulic System.

What do you think? Leave a question or comment below, and use the social links to share with friends!

Vanagon Hydraulic Clutch System Overview

Related Topics:

Clutch Master Cylinder Replacement
Clutch Slave Cylinder Replacement
Bleeding the Clutch Hydraulic System

The Vanagon’s hydraulic clutch system is fairly straightforward and clearly depicted in the Bentley manual, Page 30.2.

Vanagon Clutch and Brake ReservoirEssentially, the clutch pedal actuates a hydraulic piston-and-cylinder assembly—usually referred to as the “master cylinder”—tucked away just above the base of the steering column. This master cylinder pushes hydraulic fluid through a 10-foot-long pipe running to the engine compartment, where it is connected to a similar piston-and-cylinder assembly known as the “slave cylinder”. This slave cylinder in turn actuates a lever on the side of the clutch bellhousing to engage & disengage the clutch.

Hydraulic fluid for the entire system is supplied by the same reservoir as supplies the brake system; this reservoir is hidden behind the instrument cluster on the dash, and is accessed by removing the instrument-cluster cover.

Vanagon Clutch Fluid LeakTypically, the first sign of trouble in the clutch system is hydraulic fluid dripping from the master cylinder onto your shoe, carpet, steering column, etc.. Or perhaps a leak surrounding the slave cylinder back in the engine compartment, accompanied by an increasing consumption of fluid.

Failure of either will cause the inability to use the clutch to disengage the transmission, making it difficult or impossible to shift. Insistent pumping of the clutch pedal will result only in the loss of your precious brake/clutch fluid.

Popular Vanagon lore suggests that failure and replacement of either the clutch master or slave cylinder will soon be followed by failure of the other, the theory being that the original cylinders wear out at about the same rate—neither being stronger than the other—so they continue to function together for quite some time. But a new, strong master cylinder will easily overpower the worn seals in a tired old slave cylinder, subsequently blowing it out. On a purely speculative note, I suppose the opposite could be equally true: a new slave could be too much for an old master to handle, causing an imminent failure of the master cylinder.

Some dispute this as mere Teutonic superstition, and I don’t know for certain.

If your Vanagon racks up most of her miles on roadtrips and camping forays, then by definition any mechanical failures will occur far from home. If you prefer to perform this task in the relative comfort of your own driveway rather than a lonely interstate or a distant logging trail in the woods, just replace both cylinders at the same time and be done with it for a good long while.


  • Suitable Clutch Master Cylinder
  • Suitable Clutch Slave Cylinder
  • DOT-4 Brake Fluid, about a quart


  • Assorted Metric Combination Wrenches
  • Assorted Metric Sockets and Ratchet Wrench, with extensions
  • Torque Wrench: 0 to 25 ft./lbs
  • Phillips Screwdriver
  • Vaccuum-pump brake-bleeding kit
  • 3-foot-square piece of plastic sheeting and some ever-helpful duct tape: lay this down on your carpeting to catch the inevitable spills
  • A small inspection mirror and flashlight may help in seeing what you’re doing in the tight confines above the steering column
  • Penetrating oil: squirt some PB Blaster, Marvel Mystery Oil, or similar on exterior nuts, bolts, and bleeder screws a few days before tackling this job, to ease their subsequent removal. Even so, I needed to resort to the judicious application of a …
  • Small propane torch, to carefully heat stubborn threaded fasteners.
  • Hose clamping tool to prevent fluid loss.

DIY Hydraulic Hose Clamping ToolHere’s a simple homemade alternative to a store-bought hose-clamping tool. Cut a 1″-long section from a 3/8″- or 1/2″-diameter wooden dowel, then split it down the middle to form two half-round pieces. Tape these to the jaws of your locking pliers and use this to carefully pinch off rubber hoses while you work on related components. Not too hard though, or you’ll damage the rubber.

Proceed to “Vanagon Clutch Master Cylinder Replacement”

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