Brake fluid change

Now that my 2-post lift is operational, I am finally ready to change the brake fluid in my Dino, which is overdue. Any tricks, pitfalls, or words of wisdom would be appreciated. I assume all wheels must be removed for this operation (?)

 

you shouldn't have to remove the wheels with the car on a lift-- I can usually get to the bleeders with the car on the ground by turning the front wheels fully. The rear calipers are not a problem either.
I usually suck all the old fluid out of the reservoir with a syringe / turkey baster and fill it with new fluid. Bleed the wheel furthest from the master cylinder first then work to the closer one. If you use Ate Super Blue fluid it makes it very obvious when you have new fluid coming thru the bleeder line. Actually I sometimes mix it with new clear fluid because it has a LOT of dye in it.

 

I remove the wheels and use one of those pneumatic, one-person bleeders. Griot's garage sells a good one. It requires a bit of teflon tape around the bleed screw but the results a great. Just stop every now and then to make sure the resevoir isn't running low.

...Keith

 

Have you seen these as the solution to your teflon tape?
http://www.speedbleeder.com/

 

Yes, I have seen them - very clever. Two questions:

1) Do you think the patented thread sealing system wears down each time you unscrew and screw the speed bleeders?
2) Do you think the pressure of the springs is too high to work with an air pressure bleeder?

For the frequency with which I bleed the brakes, this may be overkill but it would make it easier.

Thanks...Keith

 

There seems to be a lot of unnecessary mystery surrounding brake fluid changes....Here is the way I have always done it and it's worked a charm every time.

Note: I do have an air powered bleeder, i.e. basically a suction device that when hooked up to a compressed air source, creates a venturi effect and draws the brake fluid through the bleed screw and into the tool's old fluid container...

1. With the car on the lift, remove the wheels.

2. Using the bleeder, suck as much of the oil brake fluid out of the reservoir as you can.

3. Put the cap back on the fluid reservoir and place a lot of rags around the base of it.

4. Grab and firmly give the reservoir a "yank" and it will come off of the master cylinder (be CAREFUL for any brake fluid splashing from the bottom "tits" in the reservoir when you do this!! Hence try to be gentle and keep those rags covering any paint, etc..in sight that could possibly get a drop of fluid on it).

5. Plug the two "tits" in the bottom of the reservoir with your fingers (or plugs), open the cap and pour some fresh brake fluid into the reservoir. Cap it back up.

6. While still keeping the two bottom "tits" firmly plugged, shake the reservoir vigorously to loosen up any grime that has accumulated in there. The sloshing action of the fluid will break up any gunk and keep it in suspension.

7. Empty the reservoir and repeat step 6 once or twice more (it's handy to have at least 2 litres of brake fluid on hand for the whole operation).

8. Position the reservoir back on top of the master cylinder, push down on it to engage the two "tits" back into the openings on top of the the master cylinder (BTW, this is a good time to check/replace the rubber seals in those M/C openings that may be leaking!).

9. Fill the reservoir with fresh fluid, all the way to the top, wiggle it a little back and forth to get any air bubbles to the top and resume filling until it is level with the opening of the neck. I use Ate (Alfred Teves- German manufacturer- actually who made the calipers on the Ferraris!) 'SL' DOT 4 fluid in all of my cars. In the 308 I use Ate "Super Blue" which is a high temp racing DOT 4 fluid. I don't track my car, but I like the extra piece of mind that a racing fluid provides when I'm driving...shall we say...spiritedly

10. Now, go to the LEFT rear (i.e. farthest caliper from the master cylinder) caliper and get your bleeder ready. Crack open the bleed screw a few turns and suck the brake fluid through (check the fluid level in the reservoir now and then) for at least 45 seconds to a minute. Close the bleed screw and move to the right rear caliper and follow the same procedure (again, keeping an eye on the fluid level in the reservoir as you're drawing it through the system - don't let it get down too low!). This time, for the other rear caliper though, I only bleed it for maybe 20-30 seconds.

11. Move to the LEFT front caliper. Follow the procedure as outlined in step 10, but bleed each of the front calipers for at least 30 seconds a piece. Note that the fluid level will begin to drop more quickly in the reservoir, as you're dealing with larger calipers and shorter length of brake line.

12. As above, but with the right front caliper.

13. Get into the car and begin pumping the brake pedal. It will feel soft at first and will gradually firm up after about 10-15 pumps of the pedal.

14. Check the fluid level again, top up if needed. Replace cap, tie a tag somewhere around the reservoir with the mileage and date of the fluid change written on it for future reference at a glance (of course, keep copious records in your maintenance log too!). Viola! You're done and ready for another year of safe driving!

** This was the procedure preferred by Mercedes-Benz when I worked for them as a mechanic when I was in college. I adopted it for my own cars and I have never gone back to conventional bleeding methods. The air powered bleeder is pricey (about $175) but worth every cent. And you do of course need a compressor. The bleeder device runs at about 125psi, so make sure your compressor can handle it. The bleeder can be bought through Snap-on trucks or I think as someone else mentioned, Griots Garage sells them. Here is a pic...It's called the "Vacula"

Cheers,
Aaron
'82 GTSi
Image Unavailable, Please Login
Image Unavailable, Please Login
Image Unavailable, Please Login

 

I've had mine 4 years and they took quite a beating when I was sorting out leaky brake boosters and replacing the MC. There have been no leaks yet; I'm not expecting any as I've never heard of them failing.

Just a note: even a single drop of brake fluid will ruin the paint. You must be sure to be careful. One pitfall is letting the plastic tube whip around while you're going from wheel to wheel. It can fling drops on the car. Takes lots of work to get the paint back to normal. BTDT.

Ken