Quick and dirty notes on flushing the E34 brakes without removing the wheels

[DanDombrowski]

I just took some time in the afternoon to flush the brakes on my 525i, still trying to prep it for the track while Im waiting for the transmission to be delivered. Anyway, brake fluid was at least 5 years old and most HDPEvents want it less than 3 months old, so I changed it.

Now, I have a Motive power brake bleeder, which makes all of this MUCH easier and simpler. I also have ramps and a floor jack, so without these three things, I'm not sure this method will work well for you, but hey, the advice is free.

1. Roll car backwards up onto ramps (use the ramps on the rear wheels).
2. Jack up the front end of the car, place on jack stands (while leaving the rears on the ramps.) You should be able to get to all the bleed screws from underneath the car with the wheels on in this config.
3. Setup the motive brake bleeder on the master cyl resivoir, pressurize to about 10-15 psi.
4. Start bleeding from the right rear until clear fluid comes out, then left rear, then right front, then left front (at least thats the order I did them in.)
5. Drop front, remove brake bleeder, roll car off ramps. Done in 20 mins!

Anyway, there are a million different ways to bleed a set of brakes, I just wanted to offer an easy way to do it using the tools most weekend mechanics have. Sorry, no pics.

[philbyil]

So what brake fluid did you use Dan?
I use Ate Typ 200 (Amber) and Ate Super Blue (around $9.00 a litre) in both my E34 and my R1150RT.
Ate has higher wet/dry boiling points than stock DoT4 and you can alternate the different types so that when you flush, the new color makes it easy to know when the old stuff is out.

[DanDombrowski]

I used the Valvoline SynPower stuff off the shelf at advance auto or autozone. It was $6.00 a litre, so not any significant price difference.

I thought about the superblue stuff, but I opted for the Valvoline because I could pick it up in the store the day I was working on it. That, and NASA tech inspections for HDPE's call for the brakes to be flushed within 30 days, so if I'll have to be flushing it out again by the next track event (after the one coming up) anyway.

I like the idea of switching between the blue and the gold though, I think I'm gonna order a batch of each and keep the garage stocked with that.

[BillionPa]

two words

SPEED BLEEDERS!

i did the front brakes in less than 15mins without even jacking the car or turning it on!

while laying on the floor, from underneath the bumber, unscew bleeder 1/4 turn, put on catch bottle, push down brake pedal 20 times while adding fluid when the reservoir is low.

repeat.

if you are racing and you do not have brake ducts, i suggest changing to a fluid with higher dry boiling point. dont even look at AP racing fluids. ate is significantly cheaper than the only other real DOT5.1 fluid out there, which is Mutol RBF600. Mutol is 3 times the price, but has a boiling point of 590F. ATE is 530F

for non racing applications (or in my mind, non bmw applications) synpower is an extreme value when changed regularly.

some volvo guys made a chart of the various fluids and their dollar value per ounce per degree!

http://www.swedishbricks.net/700900FAQ/Brake%20Fluid%20Comparison.htm

[DanDombrowski]

Yeah, the speed bleeder made it a whole lot easier than previous brake bleeds. It pays for itself on the first use. No need to pump the pedal either, which is especially good since my "help" wanders off when they're not tied down.

Anyway, I had a slight correction to my above post, I meant to say that there wasn't a significant difference in the price between the valvoline and the ATE superblue (although I guess it is a 50% difference, its still only $3.00).

As far as the temps, yes, I will probably move up to a higher BP fluid on my next swap. I want my first run in this car to be completely stock, and then I will work my way up and see how much different changes matter on the track. I think after my first event I will be moving to the ATE fluid and a set of Hawk HP+ pads or a similar track compound and see how much I improve.

Thanks for the tips. I've seen that volvo chart before - I check the volvo boards once in awhile when I need to do work on the 240.

[TC535i]

two words

SPEED BLEEDERS!

i did the front brakes in less than 15mins without even jacking the car or turning it on!

while laying on the floor, from underneath the bumber, unscew bleeder 1/4 turn, put on catch bottle, push down brake pedal 20 times while adding fluid when the reservoir is low.

repeat.

if you are racing and you do not have brake ducts, i suggest changing to a fluid with higher dry boiling point. dont even look at AP racing fluids. ate is significantly cheaper than the only other real DOT5.1 fluid out there, which is Mutol RBF600. Mutol is 3 times the price, but has a boiling point of 590F. ATE is 530F

for non racing applications (or in my mind, non bmw applications) synpower is an extreme value when changed regularly.

some volvo guys made a chart of the various fluids and their dollar value per ounce per degree!

http://www.swedishbricks.net/700900FAQ/Brake%20Fluid%20Comparison.htm
I always liked that Valvoline synthetic, great deal for low cost high performance brake fluid.

[Dukes]

Dan,

Where did you purchase that Motive power bleeder? The ones I've seen don't appear to have the right connector for the reservoir.

Thanks

[DanDombrowski]

I bought mine from FCPGroton.com. They're more popular with the Volvo messageboard folk, but they carry a lot of common BMW, Volvo, and SAAB parts.

Anyway, I got the package that has both the Euro connector and the American Universal connector (my friend paid for the whole package and I bled the brakes on his Ford Escape, then I got to keep the bleeder).

The Euro cap connector screws securely onto my E46 330Ci, 525i E34, and 91 Volvo 240. Works out very nicely.

It also uses common compressed air fittings, so if you wanted to use an air tank to simply put pressure on the system without pumping fluid, you could do that as well with just the cap.