jimmy_wrxsti

iTrader: (3)

Looking for some advice from those who have done this before - plan on purchasing some gearbox/diff fluid and some brake fluid and replacing them on my 03 WRX STi.

Now ive done some research and come up with following - does this seem right to you?

Gearbox/Diff

Front Diff and gearbox share same fluid and require about 3.8l in total.

-Drained via the drain plug under front diff housing.
-Refilled via the gearbox dipstick pipe - adding pipe to a funnel and connecting it to the pipe by the intercooler

- Rear diff housing is at back of car underneath
- Bottom plug drains, top plug to refill.
- Car needs to be level when refilling to get correct level of fluid


Obviously tricky bits include getting to the diff housing but is that all there is to it? Any other hints or tips to make this easier?

Brake Fluid

Bleeding order: starting with nearest to brake reservoir (assuming its passenger side)

- Front Passenger side
- Front Driver side
- Rear Passenger side
- Rear Driver side

- Jack up car ideally on ramps
- Remove wheels
- Spray WD40 onto bleed nipples
- Fill up reservoir tank to max and close
- Press brake pedal to remove any vacuums
- Connect one man bleeding kit to correct wheel nipple
- Remove bleed nipple cover and connect the bleeding kit tube. Undo bleed nipple
- Press brake pedal to pump out fluid - Repeat the operation until no bubbles can be seen exiting the bleed nipple
- Replace bleed nipple
- Top up reservoir fluid to Max
- Repeat for each wheel

Does this seem right? again any tips on this? Seems simple enough and can be broken up by doing front first and then rear if no ramps available.

With the topping up of the reservoir - how much new brake fluid is needed to maintain the level throughout whole operation?

JohnD

iTrader: (5)

The 6 - speed box holds 4.1 litres
There are TWO drain plugs - directly below the front diff. and in the small sump below the gearbox. You need to remove the small plastic undertray, to get to this.
Rear diff. takes 0.8 litres
The whole job is actually quite easy.

JohnD

jimmy_wrxsti

iTrader: (3)

cheers John

So 5l should cover both front and rear then?

JohnD

iTrader: (5)

As long as you don't spill any! - might be safe to get an extra 1 litre.

When changing the brake fluid, remember there are TWO bleed nipples on each of the Brembo calipers.
I've changed the fluid twice now on my STi. You can just about get away with 1 litre although as I was changing make, I used 1 1/2 litres to purge the system of all old fluid. I used an air pressure system to change mine.

JohnD