A Couple Brake Bleeding Questions - S1 3.8

I’m getting ready to add fluid and bleed the brakes on my newly rebuilt brake system. A couple questions:

  1. With the front and the rear brakes on completely separate master cylinders and fluid reservoirs, does the order of bleeding matter at all? (normally I would go R rear, L rear, R front, L front)
  2. Is a quart sufficient to fill a completely empty system? Cylinders, calipers and soft lines should all be empty. There may be some residual fluid/junk in the hard lines that may need to be flushed out.

I’m also open for any other random suggestions.

Start with the rear that is furthest from the master cyl and be prepared to work at it a while. Mine took a lot of bleeding to get all the air out of the fresh system.

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If you feel there may be ‘junk’ in some of the hard lines can I suggest you flush the system with denatured alcohol (methylated spirits) first.

Thanks, Robin! Would I just put that in the reservoir and pump it through the lines?

Just the same as a bleed procedure.

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The 3.8s can be a pain because with both circuits full of air, the balance bar will tip toward the one which is not the one you’re trying to purge currently. This prevents you from getting a full throw on the master because the pedal bottoms out too soon. Also the rear line is so long that it’s hard to get enough fluid in. There is no compression.

I tried a Mity-Vac and it does help, but it’s a pain to use and you don’t get a full purge, so you have to resort to the pedal pump method afterward. Basically it’s just useful for priming the system.

If you have some cash to spare, pushing is really the best system and it’s foolproof. Although this is designed to be filled with fluid, I never wanted to do the cleanup. So I just fill the reservoir, pump it down 3/4 of the way, then add more and pump it again.

This is the one I have and it’s the right cap size for the reservoirs. You can buy other caps for different cars.

Yeah, I was thinking about that. I’ll think about the power bleeder, or at least trying the inner tube trick some have suggested.

When I’m not in a hurry, I’ll open one rear and one front bleeder slightly and just wait to let it gravity feed. short pieces of hose can be put on the bleeder screws to keep fluid from dripping onto anything. After fluid comes, close these and do the same to the other two. Really doesn’t take long. Then you can pressure bleed if necessary.

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I would second the recommendation about the Motive Products bleeder. I have one. And like Erica says, I just use it to pressurize the fluid bottles. So that said, if your only use is going to be for the E, you can make the inner tube work in the same way, for much less money.

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“you can make the inner tube work in the same way”

I’ll second that, works very well, only thing I was surprised about was how much pressure/reservoir you need to make it efficient.

We have brakes! Bleeding went shockingly smoothly. I have speed bleeders at all four corners and the XKS remote bleeders on the rears. I sacrificed an old mountain bike tube and did the pressure bleed. No problems whatsoever. Thanks for the tips.

Also, to answer my question #2, a quart is enough to do the complete brake system and to partially fill the clutch reservoir. I need to pick up a little more fluid to finish the clutch. Haven’t really spent much time on that yet.

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Now that you have pressure, don’t forget to follow the steps to adjust the pedal box part that triggers the servo. Be super gentle with the fitting on the test port on it, easy to break, hard to replace.

Thanks, Erica! I’ll keep that in mind.

What is this Test Port wou are refering to?

On the 3.8 servo there is a two piece fitting screwed into the face, a base and a cap. You remove the cap, and connect a vacuum gauge and adjust the linkage so that you get max vacuum while still being able to release fully when it’s suppose to release. I’m speaking from memory as I haven’t done it in many years. Once set correctly it generally doesn’t change.

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