Brake success!

At last all the pieces came together!
I assembled all the brakes part a couple of days ago and bled the brakes once. My daughter pumped the brake pedal and I opened and closed all the bleed nipples. The first test run was a disappointment! The brakes enganged very far down near the floor. So today I bled the brakes onece again. This time my wife pumped the pedal. I also used a one-way valve and had my wife pump the pedal with more force. More air bubbles came out and on the test drive the brakes felt OK. The ABS seems too work as does the ESP. I didn't want to push the brakes to much since you are supposed to run-in the brakes carefully the first kilometers. The car steers to the right, but this is expected since I have changed the front spindles and also mucked around with the rear wheels. I will have to do a wheel alignment of both the rear and front wheels. Don't know if I can do that myself or if I need a mechanic to do it for me.

It feels great to get the breakes together after two months of work!

Here are some pictures!

The front brakes...

... and with the wheel mounted.

The rear wheel

Detail from the rear brakes. Note the 1mm shim between the brake carrier and the adapter plate and the stuck wrech in the back ;-)

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A snowy A2 after the first succesful test drive

The next step will be to try to fit handbrake cables. Next year...

The misfit

I got the adapter plates from the machine shop this week. I would be lying if I said they fit perfectly :-(
Somehow I must have mis-measured or mis drawn on my CAD drawing almost 2mm on the mounting holes for the stub axle bolts!

Anyway, with a good power drill, anything can be fixed :-)

The left rear wheel is now mounted, with adapter, stub axle, hub, rotor, caliper, and new brake line with a flexible hose in the end. It looks beutiful, doesn't it!

Left to do is the right rear wheel, of course and get new handbrake cables that will fit the brake calipers. The cables for the drum brakes did not fit at all. I am hoping that Biltemas cheap (SEK 129, EUR 15) cables for Audi A3 and VW Golf among others will fit.

I had hoped I would get the car running this weekend. I had all the parts (at least I thought so) and I had the time. Well, it seems like the calipers from the Skoda Fabia which fit the spindles from the Skoda Fabia, which fit the Audi A2 beutifully, maybe aren't from a Skoda Fabia at all. At least did the brake pads for the Fabias C54-II brakes not fit at all. After a lot of trial and error on the Internet with different brake systems for VAG cars I now believe that the brakes are FN 3 from VW Golf V 2005 and later. Maybe they used those brake systems on Fabia and did not include that in the workshop manuals or the scrap yard sent me the wrong parts again. Anyway, since the brakes fit great and I have now found pads form them I will keep them. I'll just change the pads and the mounting kit.
This is what the front looks like with new rotors.

I compared the old and the new brakes. The old rotors weighs 4.9 kg and the new 7.2. Quite a difference! The calipers are also much bigger.

The new rotor to the left and the old to the right

Left: new caliper. Right: old

Ups and downs and poor suppliers

Today I had some ups and some downs.
I got the used calipers for Skoda Fabia from a scrap yard today. It tuns out one of the calipers won't fit the Fabia spindles. That one didn't have a tag so I guess the whole caliper might come from a different VAG car. Just to send it back...

The two calipers. Note the huge difference in distance between the mounting holes. The one on the right fits, the left one does not.

I also started taking off the right spindle without luck. First the screw for the rotor broke so I will have to get a screw remover for it. Next the steering joint came loose before I had unscrewed the nut and the female torx fitting in the bolt went round so it all goes round and round. Ahhhh! I will try to unscrew the nut with a impact wrench or just cut through the nut with an angle grinder.
I haven't got the rotors delivered yet so I can't assemble the whole thing, but I test mounted the one caliper that was right and checked the clearance to the rim. About 7mm! I won't have to buy new rims. Great!

7mm clearance between the caliper and the rim

Finally I test mounted the rear disc brakes, stub axle, wheel hub and rotor on the car and it looks great! This is still with the wooden adapter mockup, I will try to find someone to machine me an adapter in steel next week. Get new break lines with rubber hoses next to the calipers and new handbrake cables and that should be it!

The rear disc brakes assembled. Note the old drum brakes to the left and the old drum on the floor!

Wood is good!

This weekend was more thinking and drawing than building. I designed a caliper adapter plate for the rear brakes and made a mockup in wood. The mockup made me realize that I had measured 7mm wrong. Wood is good!
Later this week I will try to find someone who can manufacture the adapter in steel for me. When I get the steel adapters I will know for sure if I have measured everything right.

The wooden caliper holder adapter mockup mouted on the stub axle together with the wheel hub, brake rotor, caliper holder and caliper

Progress!

At last some progress!
The Skoda Fabia spindles fit perfectly on the A2! Including suspension strut, drive shaft, steering knuckle, spindle joint and ABS sensor. Now I'm going to return the extra A2 spindles and Golf caliper holders I ordered and insted get some calipers and brake discs for these spindles.

The Skoda spindle mounted in th A2. Note that there are no caliper holders. They will be bolted onto the spindle.

Fits great!

Yet another dust bite

I tried my Plan C for front brakes this weekend. It wasn't at all like I imagined it would be. It turns out that in order to fit brake caliper holders on to the wheel spindle of the A2 some serious welding of the spindles is required. My contact at SFRO advice me not to weld in these parts of the car. In order to pass approval I would then have to perform and document weld tests with the spindle and do strength tests of the test welds. Naa, maybe not my cup of tea.

The spindle to the right and the caliper holder in my hand

Instead I turn to plan D!
So, what is plan D?
My friend Björn at the Audi A2 EV Facebook Group showed me a forum where people discuss upgrading the brakes on their A2:s to larger discs. In turns out there is another chassis component used in some VW Polos, Seat Ibizas and others.
I managed to find the same spindle from a Skoda Fabia so my new plan D is to use the spindles from a 2004 Skoda Fabia and the orignial caliper holders, discs and calipers from it. Wish me luck!

I did some dismantling of the rear wheel in order to measure for the adapter plate for the rear disc plates. I will probably do a mockup in wood first. It's tricky to measure right in 3D!

The stub axle between the old drum brake pads and the rear axle behind (just in front of the spring). Between the rear axle and and stub axle is where the adapter plate goes.

Below are som skethes of the original drum brakes and the planned convertion to disc brakes

Swedish to English translation

bakaxel = rear axle

axeltapp = stub axle

nav med hjullager = hub with wheel bearing

bromstrumma = brake drum

adapterplatta = adapter plate

okhållare = caliper holder

bromsskiva = brake disc (rotor)

Peter - Audi A2 : 0-1

So, I lost the first round with the A2.
I took a chance that the spindle housing (wheel bearing husing) from the 2004 Golf IV, made for 280mm rotors would fit on the A2. Well, it didn't :-(
Actually the spindle housing itself fits on the car, but the drive shaft did not fit in the spindle. And, the Golf has a different system for the ABS sensor. The A2 has magnetic type whereas the Golf seems, well different.

The Golf spindle with hub to the left and the A2 spindle to the right. Very similar...

The A2 hub (left). The Golf hub with a separate rotor for the ABS sensor (right)

I was also considering taking the hub and the bearing from the A2 and put it into the Golf housing, which was my Plan B. But I realized that 1), the manual says that the bearing and hub on the A2 is destroyed when pulled out of the housing so I would have to purchase a new one, and 2) which is worse, the fitting of the bearing in the housing does not work the same way on the Golf as on the Audi, so the bearing would not fit anyway.
Well, I gambled and I lost.
This means I have tested Plan A and Plan B so I will have to resort to Plan C.
Plan C means doing the same thing in the front as for the rear brakes. That is to manufacture an adapter that will fit on the spindle housing and allow a brake caliper from a brake system with a larger rotor to be fitted on the housing. Since the spindle housings on the A2 has built in caliper holders that prevent fitting larger rotors (which was the reason for changing the spindles in the first place) I will have to saw those holders off.
Stay tuned and I will tell you about this when I get there. As for now, I will lick my wounds...

Brake parts arrived!

So, after long time thinking I have decided how to convert the brakes. In the front will go larger (280mm) disc brakes from a Golf IV. Since the A2 has built-in caliper holders, larger discs won't fit so I'll change the whole wheel bearing housing. I bought new rotors and pads and used calipers and wheel bearing housing. The wheel bearing housing also includes wheel bearings and hubs. I hope they will fit the A2 drive shafts!
In the rear go disc brakes also from a Golv IV with new rotors, calipers, pads, and splash guards. The caliper holders are the only thing missing now. They are ordered used from bildelsbasen.se. I will have to manufacture the adapters for the calipers also.
Now I really want to start converting brakes! However I need to get the car approved before I convert the brakes so that I can legally drive it for one more year. If I don't get it approved before dec 1:st it will become illegal to drive. And I can't get it approved after I changed the brakes. I have to wait until the whole is converted to electric to get the full approval.
So, I'll sit still and plan to start conversion the weekend after next.

Brakes (the stiff Swedish regulations for converting cars)

In Sweden, if you want to convert a car newer than 1993 you have to change, not only the motor, but also the whole brake system or the steering system. This means a lot more work. I don't want to convert an older car. I want a relatively modern and safe car if I'm going to bring my family in it every day.
So, I will change the motor, the transmission and the brakes. I'll start with the brakes. I don't want the whole project to fail in the end just because it's impossible to change to other brakes on this specific car.
In order to get your converted car approved in Sweden there is an organisation called SFRO, Svenska Fordonsbyggarnas Riksorganisation, Swedish national organisation for vehicle builders. They will pre-approve the car before the vehicle inspection approves it. According to a person I have been in contact with there, I need to change the brakes to something with "different performance".
The A2 has front disc brakes and rear drum brakes so "different performace" in this case means fitting larger discs in the front and probably discs instead of drums in the rear.
The holders for the front brake calipers are an integral part of the wheel bearing housing and it is not possible  to fit a larger rotor. The holders limit the diameter of the rotor. So, this means I have to change the whole wheel bearing housing. Check out this exploded view. Nr 11 is the wheel bearing housing. See the "hooks" to the left that won't allow a larger rotor.

I hope I can find a wheel bearing housing from a VW Golf or something that can house the larger rotors. The next rotor size is 280mm.

The rear brakes do not have any "ears" to bolt the calipers onto. This means I will either have to fabricate an extra plate which bolts onto the axle with holes for the calipers or replace the a stub axle with one with "ears". This image above shhows what it looks like today.

This image below is a bolt on adapter plates for converting a VW Beetle from drums to discs.

Similar plates could be fabricated and bolted on between the rear axle (16) and the stub axle (3). another idea is to change the stub axle to one from a car with rear disc brakes with mouting holes for the break calipers. This would probably mean also changing the wheel hub and bearing. Have a look at the next image with a stub axle from a VW Golf III with rear disc brakes. Notice the mouting holes for the brake calipers in the botton of the image. The stub axle doesn't look at all the same as the one for the A2 so I guess it will involve changing a lot of other stuff as well.

Well, the search for the best solution for changing the brakes goes on...