Rebuilding brakes.

7 August 2008

Front brakes
The backing plate (the flattened edge and the self-adjuster screw slot point towards the rear, so this plate is for the right-hand side), assorted hardware and the self-adjuster screw (thick grooves for the front, thin for the back).

The brake cylinder installed, the bolts holes only align one way with the holes on the backing plates, so it’s not possible to install a right-hand cylinder on a left-hand backing plate. The plungers pushed into the ends of the cylinder.

The brake shoes, the backing plate greased, and the shoe positioned on the backing plate. The pair of shoes consist of one long and one short. The longer shoe points to the rear, the shorter one to the front.

The self adjuster hardware:

Self adjuster bracket on the shoe, and the hold-down spring for this shoe.

For this shoe (with the self adjuster) a number 4 pin has to be used. With one hand holding the pin in place (through the back of the plate, through the shoe and the self adjuster and into the spring) use a pair of pliers to push down on the top of the spring and rotate to hold the pin in place.

The front shoe put in place and its hold-down spring. This side has a washer underneath the spring.

This little bracket plate gets put on just above the hydraulic cylinder. Then a solid bar ties this plate to the self adjuster bracket. Now is a good time to put the spring on the bottom of the self adjuster.

These two green springs are identical (no left or right). They hook onto the brake shoes and stretch to the bracket plate up top.

Now for the spring holding the bottoms of the shoes together (note that it is wrong in these pictures… instead of the rear-shoe-side of the spring being hooked from underneath, it should be hooked from the top – this is so the self-adjuster screw can actually fit). Then the self adjuster screw can be put in (better to do this before the spring), be careful of the orientation of threads on the self adjuster (right or left hand threaded). Lastly, the spring on the self adjuster bracket can be installed.

 

Rear brakes
The brake hardware. There is more hardware than for the front due to the parking brake assembly. Note the thin grooves for the rear self-adjuster screws.

The rear backing plate (the adjuster slot at the bottom “points” to the rear, so this is the right-side) greased. The parking cable. And the parking cable and brake cylinder installed.

The parking brake lever installed on the cable. To make it all fit the parking cable has to be pulled tight and held that way (grips on the end work). This lever fits underneath the rear shoe.

Fitting the hold down springs and pins…

More parking brake mechanisms. Note the alignment of the rear shoe and the parking brake lever underneath it. It’s also clear to see where the cylinder plungers go. The parking brake bar is pronged on either end – the wide prongs go to the shoe with the parking brake lever. The protruding section of the middle bar should stick out from the brake. The spring on the bar is oval – this should go on the shoe without the parking brake.

A bendy bar and more springs…

The self adjuster screw installed, and the last spring (self adjuster bracket):

 

…Fully rebuilt!

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This is the rear brake assembly mounted to the rear axle.

 

To remove the backing plate the whole axle shaft needs to be removed. Begin by dismantling the old brakes. See here for a detailed step-by-step process.

 

Once the brakes are off, you can get to 4 mounting bolts holding the backing plate to the axle – through the access hole in the wheel rotor.

 

Don’t forget to remove the brake lines from the middle of the rear end (on top of the differential) into the slave cylinder.

 

Once these 4 bolts are off the axle shaft will just slide out. Note that there is no need to go into the differential to remove the axles as my Chiltons manual suggested.

 

Now the axle is out, the backing plates will slide off.

 

Install the axle shafts back in the rear end, to prevent damage.

 

Here is what that work was for:

Started with this:

 

Removing wheel studs is easy…

… just hit with a hammer and they pop through. Notice two of the removed studs had sheared, luckily there was still enough to hit with a hammer to knock them out. If there isn’t anything for the hammer to hit just use another wheel stud, thread end touching the broken stud and hit the head with the hammer.

 

To remove the hub put a piece of wood on the top of it…

And hit the wood, hard, a few times:

The hub is really grimy, so cleaned it by scraping and using Gunk (degreaser).

 

Dismantling brakes:
Here is the backing plate for one of the front drum brakes.

 

Not many steps in dismantling. One, undo the nut above the slave cylinder. This allows the knuckle to be seperated with (gentle) taps to backside of it.

 

Next is to remove the pins holding the brake shoes to the backing plate:

Easiest way is to use needle nose pliers, push down on the top of the spring, while pushing the head of the pin from the other side of the backing plate. Then you can use the pliers to rotate the pin 90 degrees and it’ll pop out the slot.

 

Now to separate the shoes from the slave cylinder:

Just push/pull…

…to stretch the springs and separate from the cylinder

 

Next just wiggle free all the brake hardware, and undo two bolts on the back of the backing plate to remove the cylinder.