Air in brakes?

[shade]

Hi all,

I changed out the pads to some low dust and when I was pushing the pistons back I opened the bleed screw on the caliper.

Now as I was pushing the piston back, a little fluid came out (as expected)
I stopped pushing on the piston and fluid stopped. At this point as the fluid stops coming out and essentially goes back into the bleeder screw can air get in?

After I changed the pads I pushed down on the pedal a few times to build the pressue back up and then went for a test. Pedal felt very low but I bedded the brakes anyways. I think the pads aren't coming into full contact with the rotor yet requiring more pedal effort. Thoughts?

 

[NBT]

Still got air in there.... after it sit's... and you get in...the brake pedal still "comes up"?

 

[Texas Yellow Fever]

You should shut the bleeder off when pressure is still on the fluid and it's still running out. If the fluid went "back in" odds are that air did too. I'd bleed them just to be sure.

All that said, how long of a test drive did you go on? On mine it took several applications of the pedal to get the pads back in full contact with the rotors. I did it before I put each wheel back on, but I recall that it did take several applications of the pedal to get them seated.

 

[RedRamRules]

As long as you did not let the piston return outward, you should be OK. Bleeding the brakes wouldn't hurt and wont take much time.

 

[shade]

Before I started the truck I probably pushed the pedal down 10 times until it felt snug then I started it up and test drove (about a 7 minute drive). This is when I bedded the brakes depressing maybe 30 times total. Each time the pedal seemed to get tighter but it still was a good way down before braking occured.

The best way to bleed now would be to loosen the bleeder valve just slightly until fluid comes out, depress the piston and then tighten it while depressing and fluid is coming out?

 

[BigRed460]

You need two people,

Get someone in the truck to pump up the brakes and then hold the pedal to the floor. Then quickly open, and the close the bleeder valve. Once the bleeder is closed have the person pump the brakes up again. A quick tip is to attach a 1/4 piece of flue line to the bleeder so the fluid doen't go every where.

 

[Marc T]

When I put aftermarket pads on I noticed the brakes wern't so grabby, which I was happy for!!

They will feel a little softer than the stock pads!!

 

[shade]

Well I had someone in the truck and I opened the valve then pushed the pdeal.
I let some fluid come out and quickly tightened it back down.
Seems a little better but the pedal has to go so far down

Ill give it a few hundred miles and if it doesnt improve Ill have a local shop bleed and refill.
Thanks all!

 

[VA VIPERAM]

For future reference, when I change disc pads, I just make sure there is enough headspace in the master cylinder for the returning fluid and squeeze the pistons back into the calipers without opening the system at all. This way, you don't have to worry about air, moisture, or anything.

 

[davo19]

i use a c-clamp to squeeze the pistons back in, never have to crack the bleed valve.

 

[Muzzy]

Check these out: Earl's Solo Bleeds.

I plan to get a set of these for my truck and my other vehicles. It will make brake bleeding much easier.

-Muzzy