Maintenance/improvement Tips - 4.2

[anchorman]

Difficulty - Medium

Time - The are 2 stages, one to adjust the brakes themselves and the other to adjust the cable.

Cable 10 minutes

Including brakes 1 hour.

Tools - jack and wheel brace, flat blade screwdriver, phillips No2 screwdriver, 10mm socket and suitable driver. Trim tool if available. 2 X 10mm spanners.

Introduction

The handbrake on all 4.2 RAVs is of the "drum in hat/exclusive" type. This consists of a small diameter drum brake which is positioned in the boss of the rear brake disc. Although a handbrake could be incorporated into the disc brake, these are becoming less popular because they rely entirely upon clamping force which requires high actuation force and are exposed to contamination if the vehicle should be used off road. Although the parking brake is efficient, it should be remembered that it is solely a static brake and should never be used dynamically because it is at a huge mecanical disadvantage - a tiny brake inside a large wheel. Even applying it just as the wheels are coming to a stand will eventually cause excessive wear of the components.

As it is a static brake the linings should last indefinitely and the brake requires little maintenance. Once adjusted after the linings have bedded to the drum it should normally not be required again for the life of the vehicle. Occasionally the drum brakes may become inefficient due to lack of use, a build up of contaminants or incorrect use.

If the linings have become wet (when the vehicle is waded to the depth of 300 - 500mm) the brake will be submerged and can be dried by applying the handbrake with a force of 10kgs for a distance not exceeding 400m at 30mph. If the linings have been replaced they can be bedded by using the same procedure but repeating the process after a cooling period of 1 minute a number of times as required. In this case the brake should be re-adjusted when completed. Once the brakes have been adjusted for the first time, any subsequent adjustment required is likely to be as a result of cable stretch. If you have no reason to suspect the brakes need further adjustment (you haven't renewed the linings etc) then it is acceptable to adjust the cable only.

The cost for having the handbrake adjusted can vary. I have heard reports ranging from £25 - £65 which I presume depends on whether the foundation drum brakes have been adjusted or only the cable.

Procedure

To adjust the foundation parking brake shoes;

Working on level ground safely chock the front wheels and release the hand brake. Observing all the usual precautions, jack up and remove one rear wheel. Ideally the vehicle should be jacked and supported on axle stands but if the supplied vehicle jack is used under no circumstances place any part of your body under the vehicle. As the disc is not fixed to the hub it is necessary to secure it by taking two of the wheel nuts and running them up to the disc. The hand brake adjuster is accessible through a rubber bung in the disc. Using a screwdriver, prize out the bung and rotate the disc (it will be stiff as you have to turn the transmission) until the toothed adjuster is visible - it will be somewhere near the bottom ;

Use the screwdriver to engage the teeth of the adjuster;

To adjust the brake you need to turn the adjuster as shown to expand the shoes;

Turn the adjuster until it is no longer possible to move the disc then turn it backwards until the disc is just free. It is OK to hear it rubbing but it should not be tight. Turn the disc a full revolution to make sure there are no tight spots. When complete refit the rubber bung and the roadwheel.

Go around and repeat the process at the other wheel but when finished do not lower the wheel to the ground.

To adjust the hand brake cable;

Go inside the car and use a trim tool or screwdriver to prize the back of the gear stick gaiter upward;

The front of the gaiter is hooked under the lower facia so just pull it back to disengage and lift it up over the gearstick but do not try to remove it. Use the phillips screwdriver to remove the 2 screws from the front of the centre console;

Fold down the back of the console and remove the cup holders to reveal the 2 fixing bolts. Use a 10mm socket and extension to remove the bolts then lift off the console. Note - it will be necessary to reach under and unplug the wire from the cigar lighter.

Now with the console removed the handbrake and cable is very easy to see;

Use the 2 X 10mm spanners to unlock the adjusting nut. Hold the bottom nut still and undo the top nut anti clockwise. This photo is from a 4.3 but it is the same;

Now turn the bottom nut clockwise to tension the cable. The specification calls for 7 - 9 clicks with a pulling force of 20kgs (44 lbs) - thats a heavy pull! The main thing is not to over adjust it so you should still feel some free play at the bottom of the lever travel. Keep adjusting and testing little by little. If you start at the bottom and pull, you should not feel any resistance until about the third click. As a check go back to the jacked up wheel and check that it turns freely.

Replace all of the trim in the reverse order remembering to re-connect that cigar lighter. Lower the remaining wheel and don't forget to finally tighten the road wheel nuts to the specified torque of 76 ft/lbs. As a final check take the vehicle to an incline where it would normally just roll and check to see that it does so in both directions. For those that might prefer the handbrake to be on with just one click don't forget that if it binds it will get hot and cause a lot of damage so whatever happens make sure you do these checks to make sure it is free.

[IanXT4]

Very useful, many thanks for all the work you have put into produce this

Ian

[gramps99]

Very useful, many thanks for all the work you have put into produce this

Ian

i agree well done, could this be put up top with the rest of the maintenace tips so its not lost ?

with a guide like this i might of had ago myself rather than take it to mr t ;) :)

[yaris781]

Thanks Anchorman, just finished doing mine would have been lost without your guide

[Big Kev]

Cheers min......joab done in minutes....you will be kept on.....

[Steve Graham]

I haven't been logged into the forum for quite a while, because everything was working perfectly! So, hello again.

Yesterday, my nearside hadbrake shoes jammed "on" and the hub and disc got rather hot. It turned out that one of the spring-loaded clips had come off, which allowed the shoe to twist out of place and then wedge itself somehow against the rotating drum/disc.

The hold-down pins and clips aren't exactly like the diagram above. In mine (2004/4.2) there's a bottom piece with a tab that locates into the shoe, then a spring, then a cap with a slot, which rotates to lock. The rear pin is not straight as in the diagram, but U-shaped (or like _--_ if you see what I mean).

I've reassembled everything and it seems OK, but I was unsure how that pin was supposed to be orientated. Does the bend point forward, backward, up or down?

I'll probably buy new shoes. Would these come with new hold-down pins, springs and clips, or is that an extra purchase?

[crofter]

As you have done the work there is little to add to what you have posted.

The pins usually are the same and so there should not be a bent one.

Their purpose is to keep the shoes from moving outward from the back plate only.

The only assumption I can make is that someone previousely had not positioned the pin and cap so it locked and which was able to slowly spin and release the pin.

The shoes only come into play when the handbrake is applied so what makes you think they need changing,as they do not wear down the same as drum brakes ?

Del

[gjnorthall]

The pictures and diagrams are actually of the 4.3 model!! The 4.2 is slightly different in that the retaining pins are dog legged, and theres a separate spring and clip (the 4.3 has straight pins and a combined spring clip). The pins and clips tend to rust and either the pin eventually breaks or theres not enough good metal to retain the clip on the pin. Due to the long life of the brake shoes - always replace the pins and clips when refitting the shoes - they're a dealer part. Alternatively there are aftermarket kits containing all the springs , pins and clips. On the 4.2 - don't worry about the position of the dogleg on the retaining pins - there isn't a specified position and they do tend to rotate in service. Don't swap pins / clips between the 4.2 and 4.3.

[Steve Graham]

Many thanks for the replies. As a further tip for anyone reading, I found that it was best to have both rear wheels off to ensure that the cable adjustment was done equally. First time round, I ended up with one side tighter than the other.