Air keeps coming back in my brake lines

[5.0GT]

Hello,

My brakes had air in the lines out of nowhere. I flushed the system twice.The second time it felt good for a few pumps then back to the spongy pedal.

I have just installed Moser axles without the ABS rings and I don't want to take it to the dealer I feel like they'll start a dumb argument that might make me want to punch somebody.

Is the master cylinder bad? I might flush it a third time just to be sure I didn't do anything silly twice, but I feel like there's a leak.

Has anyone experienced this before?

 

[BigPoppa]

No visible leak anywhere?

I see turbo in sig pic.....boiling off brake fluid maybe?

 

[5.0GT]

No visible leak anywhere?

I see turbo in sig pic.....boiling off brake fluid maybe?

No leak. It sucked in air before I drive off.

 

[basspro302]

It's really not possible for a hydraulic system to suck in air without there being a leak. Anyways it sounds like a rear caliper issue. Look and see how far the rear piston is from the pad sometimes when you compress them the piston will retract but if you pump it up the pedal is ok then when you let off the pedal the piston will retract in the bore. This only happens on calipers where you twist in the rear piston.

 

[5.0GT]

It's really not possible for a hydraulic system to suck in air without there being a leak. Anyways it sounds like a rear caliper issue. Look and see how far the rear piston is from the pad sometimes when you compress them the piston will retract but if you pump it up the pedal is ok then when you let off the pedal the piston will retract in the bore. This only happens on calipers where you twist in the rear piston.

So you're saying the rear piston is retracting after I brake?

 

[BigPoppa]

No leak. It sucked in air before I drive off.

Oh, ok. I had the understanding that this was after driving the car for a while, not immediately.

With that, I would say everything may be just fine. It isn't abnormal to have to bleed the brakes several times after having the system open for a long period (like changing the axle).

You may need to bleed them a few times then.

 

[basspro302]

It's possible it has happened on a couple cars. If you take the wheels off and look at the piston it will be far away from the pad then you pump it and the pedal comes back but once you release the pedal it goes soft until you pump it.

Other than that you can bleed it at the master then work your way back. The only other thing would be to do an abs bleed procedure but you need a factory scan tool or one that is capable. If you don't have a scan tool that can do it you can try to drive on a dirt road and get the abs to activate then bleed it again.

I would check the rear caliper operation first. Some times that adjuster inside the pisto gets stuck and will not set proper pad clearance.

 

[5.0GT]

It's possible it has happened on a couple cars. If you take the wheels off and look at the piston it will be far away from the pad then you pump it and the pedal comes back but once you release the pedal it goes soft until you pump it.

Other than that you can bleed it at the master then work your way back. The only other thing would be to do an abs bleed procedure but you need a factory scan tool or one that is capable. If you don't have a scan tool that can do it you can try to drive on a dirt road and get the abs to activate then bleed it again.

I would check the rear caliper operation first. Some times that adjuster inside the pisto gets stuck and will not set proper pad clearance.

The spongy feeling doesn't go away even of I keep pressing on the pedal. ABS is disabled on my car


I'll bleed it again with a help of a friend we'll see what happens.