[wwillsey]

I’ve just replaced front calipers. The truck sat with the calipers disconnected for several days while I got the new ones. The fluid in the front portion of the reservoir all drained out. When the new calipers were installed I filled the reservoir and bled the brakes, right front first, and get a good solid pedal that doesn’t fade. When I start the truck so the power brakes are enabled the pedal goes to the floor. The power steering pump is full.
Ideas?

 

[M37]

If your not getting any more air out when you bleed it, drive it in a safe location to see how it works. Sometime the power assist make is feel like a low pedal because you are applying a panic stops worth of pedal effort. If it isn't good, you might have an air pocket in a high area of the master cyl. You may have to level it to get all the air out or take it off and bench bleed. You shouldn't have let it drain empty.

 

[Walker111]

Brake light on? I recently bled my front brakes and the same thing happened to me. I just drove it with some sense and it worked itself out. Good pedal and the brake light went out.

 

[GAmes]

If you are going through all that trouble why not flush the brake fluid completely and bleed all four corners? If you are using the "pump it up & hold it" method I learned a long time ago to put a 2X4 Under the brake pedal to prohibit it from full travel. The theory is the master cylinder develops a wear pattern inside that is exceeded when the pedal is moved through full travel.

 

[wwillsey]

I’ve thought about flushing and bleeding all four corners. I’m concerned that the bleeders will snap off on the rear cylinders. I was only going to replace the front pads originally on this project. Then I thought flushing the front fluid would be a good idea. I soaked the bleeders with PB overnight but they snapped off on the left caliper anyway and wouldn’t come out with an easy-out. So now I had to replace the left caliper. I’ve never thought it was a good idea to only replace one so I did both. This has definitely been a case of “Scope Creep”. Any advice on getting the rear bleeders loose?
I’ll try the 2x4.

 

[ehenle4188]

Other than a tiny bit of heat on the bleeders I’ve got nothing. But worst case scenario if they snap, you replace the rear cylinders with the upgraded ones and it gives you a good reason to pull the drums off and inspect. Pretty inexpensive too

 

[GAmes]

A 50/50 mix of acetone and auto trans fluid is the best rust dissolver I know. Now that you have stroked the brake pedal through it's full stroke there is no need for the 2X4. If it damages the MC the damage is done.

 

[wwillsey]

Already pulled and inspected and adjusted the rears so it shouldn’t be a problem to take them off again. I understand the possibility of having damaged the MC, but why would it only be apparent when under hydroboost?

 

[GAmes]

. I understand the possibility of having damaged the MC, but why would it only be apparent when under hydroboost?

That I can't tell you.

 

[wwillsey]

Got the rear bleeders loose! I'll flush all four to get fresh fluid all the way around. I'll road test when I can, but this truck doesn't go out on the road in Upstate NY winters. Never has, never will.

 

[wwillsey]

Got the rears bled with no problem. All fresh fluid throughout the system. Still get air when bleeding the fronts. See the video. Air is in line as soon as I touch the pedal. Ran a whole quart of fluid through. I have video of rear. No air in rear. Could there be something wrong with the new calipers?

 

[24hrsparkey]

Why is brake fluid dripping / running off .

I never have more than a seep around the bleeding hose to bleeder screw , and im using cheaper / worse tubing .

 

[wwillsey]

Maybe there’s to much clearence in the threads on the valves. The calipers are remanufactured. Wasn’t a problem on the rears which areoriginal.

 

[Walker111]

Granted your system was full of air from leaving them disconnected, but I just swapped front calipers today and gravity bled the system. Brake pedal is the best it’s ever been.

Set the old caliper on a 6x6, new caliper right next to it, opened bleeder of new caliper, got new banjo and crush washers ready, unscrewed old line, and placed directly to new caliper with new banjo. Hung the caliper and when fluid started coming out of the bleeder, I closed it. Used a pint of fluid, reman’d advance auto/Carquest brake calipers. Probably took me longer to take off, put on, and torque the wheels.

 

[wwillsey]

These calipers have been remanufactured. Probably more than once. What I found was that the threads on the bleeders are loose. Normally I open the bleeder about a quarter turn when bleeding. This allowed air to pull into the system through the threads. What I did was loosen the bleeders about two turns and coated the threads with grease and then seated the bleeders. Then when I started bleeding again I barely cracked the bleeders open. Pressing the pedal took quite a bit of pressure but this kept air from being pulled in through the bleeders. Appears to be all set now. I'll road test when there is no chance of salt on the roads. We got 7" of snow last night and have up to 12" coming Monday so it could be awhile!

 

[YogiBayer]

Is grease better than teflon thread sealer?