Brake Bleeding Question after Component Install

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Jul 4, 2008 | 06:50 PM

jgump

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Drifting

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From: Shelby Township MI

Brake Bleeding Question after Component Install

I've changes the rotors, capliers, SUS Lines, and pads on my 1998 C5. Now I am bleeding the brakes and changing the fluid with a Motive Power Bleeder.

So far I am on my 5th run around the car. The fronts have no bubbles.

On the rear I am having some issues with bubbles. Here is what I am doing. Maybe I am opening the bleed screw too much and sucking in air.

-Fill Master Cylinder with fluid.
-Pump Motive Bleeder to 23psi.
-Tap the caliper with mallet while opening the bleed screw 1/2~3/4 turn.
-Keep tapping. I am getting one or two very small bubbles maybe spaced 1/2" apart.
-Tighten once bubble go away
-Wait an hour and repeat until no bubbles. So far only the fronts have no bubbles.
-Sequence is RR, LR, RF, LF, 1998 C5

I guess my question is how long should this process take? Am I opening the bleed screws too far and sucking in air? So far I have used 1.5 liters of fluid, which I wanted to change anyway.

Thanks,

Jul 4, 2008 | 07:01 PM

itzza427

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From: Belleville Il

Sound like you are pretty much there already. You are supposed to take it easy breaking in new pads,,so I'd take it out for an easy test drive,gradually making some harder stops which should show any uneven pull.If it is pretty good I'd drive for a few days to give any tiny bubbles a chance to settle out to one pocket then go through the sequence again which should do it for good!!

Jul 4, 2008 | 10:33 PM

TEXHAWK0

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From: Longview Texas

You might try it the old fashioned way, by just having someone hold the pedal down while you open the bleeder.
If you crack the bleed just enough that fluid starts to come out, you should not be drawing air back in...
I installed a new master cylinder and bled my whole system with only a quart of brake fluid.

The bleed sequence may be different for a 98, but the sequence on my 2004 is RR, LF, LR, RF.

Last edited by TEXHAWK0; Jul 4, 2008 at 10:35 PM.

Jul 5, 2008 | 12:34 AM

~~clayton1~~

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From: Fort St John B.C

Quote:

Originally Posted by TEXHAWK0

With the old fashioned way.
I looked in the service manual and AllData at school and sequence was (this is for a 99 btw) RR LR RF LF.

Jul 13, 2008 | 11:18 PM

jgump

Thread Starter

Drifting

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From: Shelby Township MI

I drove the car for about a week. The brakes were ok, not squishyy or anything like that.

I got board today and bleed them the old fashioned way. No air was present. They do stop a little better though.

They did get way better after throughly bedding in the pads.

Thanks,

Jul 14, 2008 | 03:39 AM

BlackZ06

Safety Car

Joined: Aug 2000

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From: San Rafael CA

Location of bleed screws

When you put the calipers back on the car with the new brake lines ... are the bleed screws at the top of the caliper, or at the bottom ??

Jul 14, 2008 | 07:45 AM

jgump

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Drifting

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From: Shelby Township MI

They are at the top. Air bubbles go up, and that is where they are relieved.

Jul 14, 2008 | 08:07 AM

BlackZ06

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From: San Rafael CA

Quote:

Originally Posted by jgump

They are at the top. Air bubbles go up, and that is where they are relieved.

That's correct .... wouldn't have been the first time someone put them on upside down.

Did you change pad material from before ??? If you switched from, say, a Hawk HP+ pad to a ceramic pad the performance fall off may be what you are noticing.