Bleeding Brake Line Question

ejsharp · #1 (**permalink**) 03-28-2008, 08:23 PM

I just did the upgrade mod to the front disk brakes on my 2000. While changing calipers the brake fluid dripped from the two front brake lines.

Tomorrow I will bleed the front lines and new calipers.

Will it be necessary to bleed the rear lines as well?... I did nothing to the rear brakes.

yspert · #2 (**permalink**) 03-28-2008, 08:34 PM

earl, to make sure you have no air in the system, bleed the rears also. why not get some nice new fluid in the system? always remember that the only thing that has to work on your vehicle is the brakes. yspert

Marty358 · #3 (**permalink**) 03-28-2008, 09:20 PM

Ditto that. Remember to start at the wheel furthest away from the master cylinder.

wirelessf · #4 (**permalink**) 03-28-2008, 09:52 PM

That would be pass. rear, driver rear, pass. front, driver front and LPBV in that order.

ejsharp · #5 (**permalink**) 03-28-2008, 10:40 PM

Thanks to all for your input. What is LPBV?

Ltning/QC10nomas · #6 (**permalink**) 03-28-2008, 10:54 PM

Since you know there is air in the front lines would you not bleed those first then the back until fresh fluid comes out then back to the front?
Just asking cause I guess that's how I've always done it as it seemed reasonable?

wirelessf · #7 (**permalink**) 03-29-2008, 01:22 AM

Quote:

Originally Posted by ejsharp

Thanks to all for your input. What is LPBV?

LPBV is the Load Proportioning Bypass Valve located by the axle on the left. It's what adjusts the trucks brake bias depending on the load.

MEvang · #8 (**permalink**) 03-29-2008, 09:12 AM

Quote:

Originally Posted by Ltning/QC10nomas

Since you know there is air in the front lines would you not bleed those first then the back until fresh fluid comes out then back to the front?
Just asking cause I guess that's how I've always done it as it seemed reasonable?

Your right, you must treat the system as to separate systems. Even if the master had emptied on the front side there should be no air in the rear side. Starting bleeding in the rear with a dry front could damage the master cylinder.
In this case the best procedure is to fill the system. Open the front bleeders and gravity bleed the fronts. (watch for a good solid drip of fluid from each caliper) Close the bleeders and bleed the right front and then the left front. Bleed the rears out to change the fluid last.
Mike

ejsharp · #9 (**permalink**) 03-29-2008, 10:20 AM

Thanks guys. Did not know that! I would have done the rear first as I learned when I was about 16 years old.

Also thanks for the info about the load adjustment. Never knew there was such a thing!

ejsharp · #10 (**permalink**) 03-29-2008, 01:08 PM

OK... I taped on the new calipers with a light duty hammer as I bled the front lines and new twin cylinder calipers. Then went to rear and then the LPVB.

The pedal improved after doing the rear and LPVB.

Again... thanks to all for your input.

ejsharp · #11 (**permalink**) 03-30-2008, 05:53 PM

The pedal was a bit low however and seemed a wee bit mushy. I then adjusted the star wheel of the rear brakes.

AND THAT WAS THE SOLUTION!

Brakes now grab nicely.

I'm so happeeeeeeeeeeeeeeeeeeeeeeeeeeeee.

Lockjaw · #12 (**permalink**) 04-12-2008, 08:01 AM

I just made sure I kept fluid in the master cylinder while I had the lines open so it never went dry.