314mm brake upgrade (2/2)

Article October 21, 2018

314mm brake upgrade (2/2)

Words count 7.5k Reading time 7 mins.

I was really excited for the parts to arrive and luckily they came pretty fast. Tuesday I was already greated by the brake pads, followed by the rotors and clamps on Wednesday and the calipers on Thursday afternoon.

What shall I say? Alone the weight of the parts astonished me. The bottle in the title picture is a 1,5l one - so you can imagine how big it is.

One rotor was around 9kg, the calipers must have been around 6-7kg. At the same moment I was a bit afraid, if this would make braking too harsh and uncomfortable. Another letdown were the used calipers, one dust cuff was broken and their paint was pretty wrecked, while I planned to repaint them anyway, they look really crappy for the moment being.

Nonetheless my current brakes were way too worn to keep them running. Rather a bad looking car than one with serious issues.

No time to waste - lifted the car up, took the rims off and removed the old parts.

Brake hose

One “problem” I often saw at beginners is that they let the brake hose bleed all the time. To avoid this mess you can put a brick on the brake. Also be sure to remove Fuse 6 from the dashboards electronical compartment (open up the drivers door), this way the brake lights will stay off.

Dust shield

As stated in my previous post the dust shields need to be adjusted. Since it was already late and about to go dark outside, I went for cutting, instead of bending, which went fast and easy. Just be careful around the tie rod as its relatively close to the dust shield. Once cutted I smoothed out the edges a little.

Caliper preparation

The calipers came with preinstalled valves. However, those seemed relatively rotten and since I didn’t want to have a bad surprise, when I would bleed the brake system, I removed them and put my “old”, but excellently looking valves in. The valves were closed down way too tight and were hard to remove. Thanks to the help of rust penetrator I was successful anyway.

The sliced dust cuff was a bit unpleasant to look at, but at least the cylinder was still sealed properly. Fixing this is around 10€ and will be done by me, once I will paint the calipers.

Last, but not least, you add the brake pads. The 314mm system has two directional pads. Therefore, I do recommend to check out whats written in the installation guide, which comes with the pads!

Installation

Installing the new system is done in reverse order. Before doing so be sure to have cleaned the wheel hub properly.

  1. Put the rotor on and tighten it with the holding screw. If you have lost it, its not a problem, since the wheel holds it in place. Until then I recommend putting a few bolts on so it remains in place.
  2. Next step is to add the brake holders. Those need to be torqued with 210Nm+30°. This might also be the right moment to clean the brake rotors with brake cleaner.
  3. Now you can put the caliper on and insert the guide pins. Tighten them down with 28Nm and put the dust caps on. Make sure that the guide pins are clean and not anyhow greased.
  4. Only two more steps and you are about to be done. You can now put the clamp on. A third hand or foot might help here. Center the clamp so that its inner guide can run into the hole. Hold it this way with a foot/third hand. Now you can push down the sides. Wiggling the middle might help a little.
  5. Put the brake hose back on. This one is tightened with 40Nm. IMPORTANT! Do not forget the two copper seals!

This is it. Repeat the same on the other side.

Bleeding the system

Unfortunately I do not own equipment to bleed the brake system, but this is not a problem at all. What I do is really simple, yet effective if done right.

All you need is just a bottle and hose, which you can put over the valve on the calipers and a second person. You need to put some brake fluid into the bottle, so that the end of the hose is covered in it. Logically the other end belongs on the valve.

Remove the cap of brake fluid reservoir. Now open up the valve and tell the second person to push down the brake pedal to about a third of its way. Pushing it further might damage the main braking cylinder. Do this until no more air bubbles come out.

IMPORTANT!

Do not let the reservoir run dry. Otherwise you can start all over again. Once bleed, you can close the valve (16Nm, so do not close them too hard, you can feel when its enough). Let the person pump up the pedal. It should start to feel hard.

Repeat this on all calipers. According to Saab this is the order to do it:

  • Front left
  • Rear right
  • Front right
  • Rear left

Once done pump up the pedal again. It should feel rock solid, like you would hit a brick with your feet.

If you closed the reservoir again and are sure that the pedal gets hard you can reinsert the fuse and turn the engine on. The pedal becomes soft again, which is related to the brake cylinder. If you feel insecure, whether or not everything is fine, turn the engine off and pump the pedal again.

Brakes should feel very hard again. If yes, you did everything right and should not be afraid.

First drive

At the beginning the car will feel weird to brake. Brakes will feel like they wouldn’t brake at all the very first time. This is absolutely normal and should be kept in mind. The first 200-300km you have to be really careful about not braking too hard.

Its also recommended to brake the brakes in. To do so, you should brake from 40kph to 10kph with medium pressure. Repeat this process with pauses so that the rotors can heat up. Doing this too fast or harsh will ruin them.

After around 30 of these cycles, you will feel that the feeling and response of the brakes will greatly improve. After around 100km the brakes felt really good and safe, yet I still am a bit careful until I haven’t done at least 200km with them.

Inspecting the old brake system

Even though I inspect my brakes regularly, I was really suprised how worn the inner pads were. Not only they were worn, but also burnt. They had simply no chance to withstand such severe punishment.


Surprisingly the rotors were in very good condition, same for the calipers, holders and clamps. Those were in such a good condition that I deciced to sell them alongside with the calipers.

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