═══════════Frequently Asked Question═══════════

Author: YURIY-GX71

So, another weekend spent productively on behalf of March. The reason for the overhaul of the brake calipers was our 'good' rainy summer in Primorye (it's like a flood on the roads)) and after getting wet, the brakes on my March started to catch and heat up the brake discs significantly. Original repair kits for the calipers are quite expensive and take a long time to arrive, so I found analogous spare parts under the original numbers (04479-22010 - rear, 04479-30090 - front) from some company SAM and waited for the weekend. Each repair kit cost me 600 rubles. During the overhaul, I was shocked by the poor condition of the calipers' internals, especially the brake cylinders and pistons. On the front calipers, the dust boots on the pistons were severely torn. The pistons showed slight signs of rust, but I wasn't prepared for this and didn't have new ones in stock, so I cleaned them up as best I could and put them back into place. As for the analogous repair kits – everything fit perfectly like originals. Since this was my first time repairing this part of the car, I noted some important aspects regarding the correct sequence which I will try to outline below. So,
Sequence for overhauling rear calipers:
1. Loosen two bolts on the piston housing (do not remove the base of the caliper);
2. Remove the housing without detaching it from the brake hose;
3. Pump the brake pedal until the piston comes out of the cylinder (it’s impossible to pull it out by hand, I tried)) );
4. Detach the brake hose from the housing and plug it with a wooden dowel, for example;
5. Disassemble the piston housing, clean the pistons and cylinder from any dirt, and clean the seating areas of the seal ring and dust boot;
6. Install the seal and the piston with the dust boot in the correct sequence as shown on the photo:
a) install the seal;
b) put the upper lip of the dust boot over the piston while leaving the lower lip free;
c) insert the lower lip into the seating area before mounting the piston in the cylinder;
d) slowly push the piston into the cylinder with a small pulley puller, for example, to leave as little air in the cylinder as possible and make it easier to mount the housing onto the hub.
7. Replace dust boots on the guide sleeves, with the procedure of mounting the sleeves with dust boot similar to that for the piston;
8. Mount the assembled housing back onto the hub, attach the brake hose, bleed brakes by releasing air. Done!

The sequence for overhauling front brakes is basically the same, but there are some nuances:
1. Loosen two bolts on the piston housing (the upper bolt loosens partially because of the brake hose and cannot be fully removed, while the lower bolt can be completely unscrewed) without removing the base of the caliper;
2. Remove the housing without detaching it from the brake hose;
3. Pump the brake pedal until the piston comes out of the cylinder;
4. Detach the brake hose from the housing and plug it with a wooden dowel, for example;
5. Remove the housing and base of the caliper;
6. Replace the seal and dust boot on the piston in the same sequence as for the rear caliper;
7. Replace dust boots on the base of the caliper;
8. Mount the assembled base and housing back onto the hub, attach the brake hose, bleed brakes by releasing air. Done!
That's about it. By the way, since last year I had original brake hoses from Exist lying in my garage, so I also replaced them (the originals were cracked). Hopefully, someone will find this description useful.
Photos related to this procedure are attached but I’ll split it into two posts to upload all photos! First of all, photos of the rear caliper overhaul.