Starting from scratch - bleeding brakes

[garment]

Hello Pelicans:

I am at the last step of my '83SC suspension refresh - bleeding my brakes, my first time.

Apparently, I lost all the brake fluid from brake lines while I was doing the suspension - the reservoir is empty. So, I suppose I will the reservoir and then attach my Motive pressure bleeder and proceed around the vehicle in the proscribed manner (right rear caliper first, etc.). I will clamp off the overflow line as well.

Any other tips to use the Motive or tips in general for a first-time brake bleeder?

Thanks, Pelicans!

[Trackrash]

Porsche 911 Brake Bleeding | 911 (1965-89) - 930 Turbo (1975-89) | Pelican Parts DIY Maintenance Article

[Tremelune]

You've pretty much got it. Make sure the bleeders aren't rusty, or now is the time to replace them. Check the lines, pads, calipers, etc...

If there's air in the system, there's a good chance you'll need to do a full bleed twice. The initial bleed to get fluid into the system, a test drive to work the components and jostle everything, and then a second bleed to remove the air that stayed behind. It all depends on how the pedal feels and how the car behaves when the tires start locking up (worth testing).

You might be able to bleed the system twice with 1L, but I'd have 2L on hand. You can't really bleed too much.

[Ayles]

I would also have have new bleeder screws on hand. They are inexpensive insurance, I had a hell of a time two of mine open and they were damaged getting them out. Speed bleeders are also a good option to install for future ease of bleeding.

[Trackrash]

What I do every time I bleed is to "exercise the calipers".

Put a stick on the brake pedal that will hold it down a couple of inches. Does not need to be down hard, only to keep fluid from returning to the reservoir.

Go to the right rear open the bleed screw and push back the pistons into the caliper.

Close the bleed screw. Pump the brake pedal until firm. Check brake fluid level.

Repeat for the other three wheels.

Then bleed as you would normaly do.

I hook my compressor to the overflow hose. Instant pressure bleeder.

NOTE: WARNING, DO NOT USE MORE THAN 10 PSI . or you may have to buy a new reservoir.

[Tremelune]

I usually go 15-20psi...

[Taxi!]

Originally Posted by Ayles

I would also have have new bleeder screws on hand. They are inexpensive insurance, I had a hell of a time two of mine open and they were damaged getting them out. Speed bleeders are also a good option to install for future ease of bleeding.

I agree with either having new bleeder screws (they're called ventilation valves in PET, I think) or cleaning your old ones out before you add fluid to your system. I just tried to bleed my new-to-me '86 951 with turbo calipers (two bleeder screws on each caliper) and only found one out of eight screws was fully functional. I tried using my air compressor but that didn't work on a consistent basis. Since I had fluid in the system, I really couldn't take them all out and soak them in alcohol to clean them, so I ended buying eight replacements and switching them all out.

If the OP has a Motive Power Bleeder then he doesn't need Speedbleeders.

[T77911S]

I removed all calipers and the MC on my 930, except lines. but I did blow all the old fluid out of the lines.
I just open the bleeder at the calipers and let it drain naturally.

[shadowjack1]

speed bleeders area the way to go. Makes this a one man job.

[Tremelune]

Speed bleeders only provide value if you don't have a pressure bleeder, and given the choice between the two, I'd take pressure all day...

[Flojo]

Originally Posted by Tremelune

I usually go 15-20psi...

if you have an old mastercylinder, it might wreck it, kill the seals...

but yep, same here, 1.2bar equavalent to aprox 17psi.
I use "easybleeder" with spare reservoir and a partially deflatet tire as pressure source.
works like a charme.

[fred cook]

Lots of good tips here. One I did not see was to block off the vent hose on the top/side of the reservoir. Otherwise, you will pump brake fluid into the driver side floorboard! Not a total disaster, but messy to clean up! Another is to use a 6 point box end wrench to loosen the bleeder valves, especially if they are stuck. A 12 point box end wrench will tend to round off the corners on the bleeder valves.

The last time I had to bleed brakes, it was after replacing brake hoses and calipers on a Jaguar. I used a hand operated vacuum pump to pull a vacuum at the bleeder valve and then worked the brake pedal a couple of times for each caliper. This seemed to make it easier to get all the air out of the lines and calipers. Good luck!

[tobluforu]

Speed bleeders worked great for me back in the day at auto-x's, but the motive is awesome. I left the speed bleeders on there just in case, but haven't used them in years.

[911 Rod]

Originally Posted by fred cook

Lots of good tips here. One I did not see was to block off the vent hose on the top/side of the reservoir. Otherwise, you will pump brake fluid into the driver side floorboard!

You have a problem here. It should come out beside the driver's front wheel.
Mine does a little squirt at the track sometimes. You really think Porsche would design the overflow to come out in the cabin?

[Jesse16]

Good tips all. Using motive putting no fluid in the motive and refill the cars reservoir after each wheel. You can get a little ball valve at the home store and splice it into the motives line to your reservoir cap which you can close each time you need to re-fill. That will hold the air in the tank and take out 90% of your pumping. Getting a little nice quality 8mm (for mine), 6 pt or what-ever size box end wrench fits. They are little hollow screws so careful tightening.
And as everyone reminds, clamp off that overflow. Multi-messes here over the years !

[Discseven]

Anyone know for sure what size speedbleeder '80 911 requires?

Speed Bleeder Sizes

[911obgyn]

If you do a pedal bleed make sure you put a block under the brake pedal so it does not go to the floor, or the piston cups in the MC may get damaged scraping across debris or corrosion when it travels past the normal travel limit.

[Tremelune]

If you're bleeding your brakes every two years, what is the likelihood the master cylinder will get damaged? If it gets damaged during a bleed, isn't it time to replace it anyway?

Many newer cars (such as the Cayman) specify full pedal travel as part of the factory procedure for bleeding.

[3rd_gear_Ted]

When the power bleeder somehow or another causes a mess, it gets real exciting out on the track when the spilled fluid finds its way into the pedal cluster low spot and then migrates out under your feet mid session. Live and learn

[will hung]

I used a power bleeder followed by the partner pumping the brakes method, but was never happy with the firmness of my pedal. Then I gravity bled them. It was the best thing I ever did. Takes much longer, but you are rewarded with a super stiff brake pedal.