Citroën HY front brakes

In order to clean the brake cilinders and adjust the brake segments the drum had to be removed. Behind the drum there is a wheel brearing connected to the drum. Therefor to remove the drum a special slide hammer is needed. I decided to make one so that this in the future would be a relatively easy job. The slide hammer is made of angle iron and some flat (10 mm) pieces. The slide is a piece of round scrap metal sliding over a rod. The whole is firmly welded together. The advantage of this assembly is that the original wheel bolds can be used to fix the puller to the drum.

Do not try to get the drums of using a hammer tapping the edge of the drum. The change of the drum cracking or even breaking is very big.

To pull the drum off the slide hammer is used. Because the rod of the slide hammer is in the center of the drum, the drum comes off nicely. Put something soft under the wheel because if the drum comes off suddenly it can crack when falling on the ground.

As can be seen on the picture the brake cylinders are of the single piston type. I removed the brake pads and cilinders and cleaned all the parts. The cilinders were cleaned using a honing device and put together using dot4 brake fluid. I reassembled all the parts. I do not have a brake pad allignment tool for the HY so I placed the drum and turned the excentric pads until the break pads touch the drum lightly. I removed the drum again and measured the distance of the outside of the break pads to the inside of the ring holding the wheel bearing. I used a slide gauge to measure the distance and adjusted the pads in such a way that they will almost touch the drum on both sides of each brake pad when mounted. Then the drum was mounted permanently again.

When the wheel rim is removed it is also easier to check for wear in the swivel pins and steering knuckle. All grease points recieved some grease. Lastly deflate air from the braking cilinder and brake pipes which might have been trapped during assembly of the cleaned Cilinder. When pressing the brake pedal it should not feel spongy but it should feel firm.

TIP: Drain some brake fluid every year so that 'fresh' brake fluid gets into the cilinders to prevent the cilinders to block.