Assembly_190. ETK_34_Rear wheel brake lining wear sensor ATE (part 1)
For BMW E30, rear brakes could be with brake drums (4-cylinder engines), with conventional brake discs, or with ventilated brake discs (only all-wheel drive 325ix Touring). On conventional Touring, the rear calipers differ from sedans - their piston diameter is 2 mm larger (35 mm instead of 33 mm). Manufacturer - ATE.
Calipers from Touring can be installed on a sedan - a kind of "upgrade" of the brakes, but I don't know how effective it will be... Calipers from all-wheel drive 325ix Touring can be installed on a sedan only in assembly together with brake discs and hubs. It will also be necessary to install wheel rims with a larger offset (ET). Therefore, there are also doubts about the feasibility of this "upgrade". Moreover, such calipers are not so easy to find. I have only seen them on sale once in all my time. At first I wanted to buy one, but I changed my mind.
The M3 has its own calipers, similar to the E32, but I don't know if they are interchangeable with the regular ones.
So, in my case, these are ATE calipers for a sedan with regular brake discs.
Rear wheel brake pad wear sensor ATE
Part #1 - brake caliper housing left (34 21 1 153 243) and right (34 21 1 153 244) - 2 pcs. Fully assembled.
Part No. 2 - brake caliper housing left (34 21 1 160 397) and right (34 21 1 160 398) - 2 pcs. Complete with piston.
Part No. 3 - brake pad bracket (34 21 1 160 396) - 2 pcs. The bracket is the same on both sides.

Part No. 4 - bolt M10X30 (34 21 1 153 937) - 4 pcs. Caliper bracket mounting.
Part #5 - Bleed fitting (34 11 1 153 197) - 2 pcs. I use Quick Brake 0088 fittings.
Part #6 - Protective cap (34 11 1 153 198) - 2 pcs. I use Quick Brake 0126 caps.
Part #7 - Retaining spring (34 21 1 153 199) - 2 pcs. I use BOSCH 1 987474 032 spring set.

Part #8 - Guide pin (34 11 1 157 041) - 4 pcs. They are in good condition, so I left them.
Part No. 9 - brake pad wear sensor (34 35 1 179 819) - 1 pc. Installed only on the right caliper. I use a TRW sensor.
Part No. 10 - terminal (61 13 1 361 897) - 1 pc. This is an error in the ETK - this terminal is for earlier BMW models to fix the brake pad wear sensor connector. It is not used in the E30. Part No. 18 is used instead.

Part No. 11 - brake disc 258X10 (34 21 6 755 407) - 2 pcs. I use TRW discs. Although, I replaced them a long time ago, their thickness is still within tolerances with a large margin. Therefore, I left them.
Part No. 12 - bolt with internal hexagon M8X12 (34 11 1 123 072) - 2 pcs. Fastening the brake disc to the hub.
Part No. 13 - protective cover left (34 21 1 162 061) and right (34 21 1 162 062) - 2 pcs. I use KLOKKERHOLM covers.
Part No. 14 - bolt M6X8 (34 11 1 156 427) - 4 pcs. Fastening the protective covers to the lever.
Part No. 15 - spring washer B6 (07 11 9 932 099) - 4 pcs. Attaching the protective covers to the lever.

Part No. 16 - plug (34 11 1 154 979) - 3 pcs. Rubber bushing plug. I use plugs from the Frenkit 233003 repair kit.
Part No. 17 - plug (34 11 1 154 978) - 1 pc. Plug for the lower rubber bushing of the right caliper with a clip for fixing the brake pad wear sensor wire.

ATE number 11.8190-0157.1

Part No. 18 - bracket (34 35 1 153 966) - 1 pc. Bracket for fixing the brake pad wear sensor connector.

Part No. 19 - not used.
Part No. 20 - caliper seal kit (34 21 1 153 194) - 2 pcs. The original kit includes a rubber seal, a dust boot, and a retaining ring. I use Frenkit 233003 repair kits. The kit includes all the necessary parts.

Even unnecessary parts, they are probably used for other car models.

But looking ahead, I will say that from this repair kit I used only a rubber seal, a piston dust boot, and a retaining ring.
Part No. 21 - repair kit for guide bushings (34 11 1 157 038) - 2 pcs. I use ATE 11.8171-0022.1 bushings.
Part No. 22 - set of brake linings JURID 508 (34 21 1 158 912) - 1 pc. I use TRW GDB299 brake pads. I replaced them just a few weeks before I disassembled the car, so they are practically in new condition. I left them.
Part No. 23 - 3G brake pad paste (83 19 2 158 851) - 1 pc. Anti-squeak grease for brake pads. I used one package for each caliper.
In the previous post about calipers, I already wrote in detail about all types of greases for brake calipers. I use them.
As I said earlier, my club colleagues criticized my choice of repair kits, arguing that Frenkit, like other Chinese analogues, is not of very good quality. Moreover, after trying on the seal from the Frenkit 233003 kit, it seemed to me that it was too big. I thought it had a diameter of 35 mm, for Touring.
It did not want to fit into the cylinder groove. Looking ahead, I will say that I was wrong, and it does fall into place, although not easily.
So, I decided to order both original ATE repair kits, since the BMW kits are no longer available, and their price was not low. But, unfortunately, the ATE 11.0441-3302.2 caliper seal repair kit. is also no longer available. Therefore, the rubber seal, piston dust cap, and circlip will remain from the Frenkit 233003 repair kit.
The ATE 11.0101-5402.2 repair kit is available for order. It includes two bushings and three plugs (two regular ones and one with a clip for fixing the brake pad wear sensor wire). Its price is 11 Euro per caliper. But using the old ATE bushing number 11.8171-0022.1, you can order bushings separately, one by one and much cheaper - 1 Euro per piece.
Since I already have three plugs from the Frenkit 233003 set, and one plug with a clip is original ATE, I decided to order four bushings separately.
And here is an interesting nuance.
In the diagram in ETK there is some part without a number, which is included in the original repair kit BMW 34 11 1 157 038 - circled with a blue line.
I was curious what it was... I found a lot of photos of this old original repair kit on the Internet, but there was no such part there. Photo from the Internet.
But it was found in a photo of old, still factory, bushings from a teammate.
There is a plastic insert in the middle of the rubber bushing!
I compared my old and new ATE bushings and Frenkit bushings.
There are no plastic inserts in any of them!
That's why I'm really curious - what kind of inserts are those? What are they for? Why aren't they in the new bushings? Maybe they were only installed on the factory assembly line? How critical is their absence? If anyone knows, I'd be very grateful for the information.
Now, finally, we start assembling the calipers.
We lubricate the cylinder and seal with ATE hydraulic assembly paste. We insert the seal into the cylinder groove. It fits very tightly.
Then we lubricate the piston and the boot with the same paste. We put the boot on the piston in this way and insert the piston into the cylinder.
We press the piston into the cylinder and put the boot on the caliper.
We wipe off the excess paste and fix the boot with a retaining ring.
We lubricate the fitting with copper grease, put a rubber cap on it and screw it into the caliper.
Now we need to install the rubber bushings.
To make the bushing easier to enter the caliper, we lubricate its OUTER part with silicone grease. We insert the bushings in this way.
We insert the guide fingers into the rubber bushings. An important nuance - the guide fingers are NOT LUBRICATED with any lubricants!
We screw the caliper to the bracket with the guide fingers. The bushings are closed with plugs. The caliper is assembled.
The calipers are ready for installation.
The metal clip in the photo above is an extra detail. As I said above, it is used for earlier models E12, E21, E23, E28.
I will write about the installation in the second part.