Jul 302023
 

Earlier this month I completed the washer fluid repair I talked about in a previous post. The windshield wiper system in my E39 M5 was leaking in multiple places. While planning for the DIY I also had the shameful (for an enthusiast) realization that it had been four years since I had changed the car’s brake fluid. So that got added to the list as well.

RevTech Performance in Sterling, Virginia was the site of the DIY. In addition to the maintenance work there was a block party with a food truck, DJ, sway giveaways and dyno runs that could be reserved in advance. I’d highly recommend RevTech to any owners in the area. Foreman Reno and his team were helpful when any of us had a question about our jobs.

Based on what I saw last month I knew the hose that runs from the engine bay down to the reservoir tank was my main problem. Once I got it out I was surprised to see how chewed up it was. There was a gaping hole high up and a slice farther down below. No surprise when I added fluid it was going straight onto the pavement. The new BMW hose has a slightly different design and I should not have to worry about this again.

Wow that was bad

When I removed the inner lining behind the passenger side wheel I saw the hose wasn’t the only problem. There was a slow leak developing at the base of the main washer fluid pump. The blue color of the fluid made it easy to see where the leak had started. I replaced the washer pump and its grommet.

Nip that leak in the bud

Changing the brake fluid is a straightforward process, albeit tedious and potentially messy. You use a pump connected to the brake reservoir to build some pressure, then release screws at the top of the calipers. Brake fluid is hygroscopic, meaning it absorbs moisture over time. So it should be changed by time, not by mileage. Official BMW directions are every two years, but you can safely go three if you don’t track your car. I had let four years pass since the last change – I’ll blame the pandemic for causing me to lose track.

Pump the bleeder to 15-20 pounds pressure
Catch Can
Close up of bleed screw

For the first time at one of these DIYs my car wasn’t the only 2002 M5. New member Michael brought his 02 Alpine over caramel, a very rare combination. His car is one of only 59 delivered to the North American market. We traded compliments and resources, and since he intends to drive the car as a daily he will be purchasing the donut spare tire from Bimmerzone. It will be fun to compare notes with Michael and assisting each other in upcoming DIY events.

Stay cool out there and save the manuals!


 

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