Saturday, 15 July 2017

Subaru Forester Front Brake Pad Wear Indicator

When I first started driving in 1974, you had to check the thickness of the friction material on your car's brake pads regularly. If you did not, it would wear down to the backing plate. This caused metal to metal contact and ruined the disk.

In the 1980's, manufacturers put two wires in the friction material. Once the minimum recommended thickness was reached, the metal of the disk created an electrical connection between the two wires, switching on a dashboard warning light.

In my wife's 2004 Forester, Subaru adopted a much simpler mechanism. They attached a thin strip of spring steel to the end of one brake pad. Once the friction material has reached its minimum recommended thickness, this steel strip contacts the disk. It does no damage but causes a very annoying squeak, telling you that the brake pads need to be changed.

This first happened after the vehicle had done somewhere between 40,000 and 50,000 miles. I changed the pads and the noise stopped. It happened again somewhere between 90,000 and 100,000 miles. On that occasion I changed the pads and disks. The vehicle has now covered 142,000 miles and the noise has just returned so I decided to take a couple of photos. The first shows the two brake pads from the left hand side of the vehicle. The pad at the top is shown side on with the friction material to the top of the picture. The spring steel strip is attached to the left hand end:

The second photo shows the spring steel strip in more detail. You can see that the end of it is in line with the exposed surface of the friction material, which only has a couple of millimetres of wear remaining:

15th July 2017: Shared with Subaru Forester Owners (Facebook group).

Saturday, 28 January 2017

2004 Subaru Forester Rear Differential Oil Change

When our Forester was new, Subaru serviced it for us and we expected them to know which items to repair/replace at 12,000 miles, 24,000 miles etc.

The Subaru dealer is a long way away so, once the car's warranty had expired, we took it to a local independent garage instead.

It is difficult for these garages to know what servicing may already have been done elsewhere. They therefore tend to do a 12,000 mile service and write advisory notes on your bill suggesting further work which may be required. It is important to read these advisories. After all, you have paid for a skilled mechanic to produce them for you.

When our Forester was serviced at 132,000 miles, the bill advised that the rear differential oil needed to be changed. Without going back through all the receipts, I had no idea when this job was last done so I decided to tackle it myself.

There are no flat areas on my drive so I parked the car with the back lower than the front to help the oil to drain out. I looked under the back of the car and saw the differential filler and drain plugs. Incidentally, they were not leaking, the picture was set up after draining the oil:

Using the ring end of a 17mm combination spanner, I removed the 2 plugs and let the oil drain into a container. By the time I took the photo, it had all drained out:

 The drain plug is on the left in the photo below. It has a magnet in the centre to catch small pieces of steel but it was clean. The old oil was clean too. The drain plug has a sealing washer, shown in the centre, which I did not renew. The filler plug is on the right and has no washer:

I chocked the front wheels, raised the rear of the vehicle until it was level and supported it on axle stands. Then I refitted the drain plug and washer.

Subaru specify a variey of oil viscosities for the rear differential dependent on the ambient temperature. I chose Carlube EP80W/90 Hypoid Gear Oil. According to Subaru's service manual, you need 0.6 imperial quarts to refill the rear differential:

I filled the differential with fresh oil up to the bottom of the filler hole, refitted the filler plug, test drove the car and checked for leaks.