2003 4Runner Brake system flush by Bulldog
It is recommended to flush the brake system every 2 years or so to avoid moisture absorption and premature damage to seals and components. Basically suggested to have the brake system last much longer and work better in the long run. I had my system flushed by the dealer last year in 2005, at the 2 year mark. So it was not really necessary to do it this year, but I was installing stainless steel brake lines so I decided why not flush the brake system while Iím at it.
I decided to use synthetic brake fluid as it is supposed to have lower moisture absorption and also exceeds both DOT3 & 4 specifications. I used Valvoline synthetic fluid as it was easily available and looked like a pretty good product. Castrol also makes a good product, but it was not available locally. It takes more than 1 qt of brake fluid, so I just got 2 to be safe. the 4Runner certainly has a big reservoir. More info on the fluid can be found here at the Valvoline site.
To make the operation easier and quicker I got a vacuum bleeder from Motive Products. It is actually a multipurpose vacuum extractor, which can be used for engine oil, diffs, etc. It comes with a tube for engine oil extraction and other oils, it also comes with an additional tube that slips onto the oil extraction one to extract brake fluid and also slips onto the bleeding nipples on the brake calipers. It is pricey at around $60, but other products are also available. More info can be found at their site. Below is a pic of mine, the gauge is a nice touch to show the vacuum in the unit.