Ble brakes 20+ times... Air STILL coming out!

[CN Spots]

1999 Ford Windstar 3.8L ABS Disc/Drum

Wife said pedal went to the floor so I started to bleed the system today. After spurting air out of the lines for more than 20 cycles I gave up. The fluid got so low (prior to me working on it) that I think the MC started pushing air. I ran a quart of fluid through it trying to get the air out. I'm out of ideas so I'm send up a signal flare for help.

1. If air got into the MC, will it (the master cyl) need to be removed and bench bled like a new unit now?

2. can these models be bled traditionally or do they need to be vacuume bled only?

Thanks,
spots

 

[Bob_VT]

Re: Ble brakes 20+ times... Air STILL coming out!

Ford still uses a shuttle valve (if I remember right) and it can be a PITA.

Get a rubber hose and bleed the brakes into a jar 1/2 filled with fluid. You will still have to do the MC fill but you will not lose ground so quickly.

Do you have any brakes? I would bring it to a mechanic and have it done since I no longer enjoy working on my back.

 

[CN Spots]

Re: Ble brakes 20+ times... Air STILL coming out!

It's weird... The left front and right rear are the problem, the other two had no air in the lines. I read something about it being a diagonal system which would explain the criss-cross inconsistency but doesn't explain why I can't get the air out.

I also read about the jar trick but I thought it was just to catch the overflow so I didn't use one.

Haynes says on ABS systems to do the tube in the jar thing and then open the bleed screw and pump the brakes 25 times with the screw open. That sounds counter-productive to me.

 

[jonesg]

Re: Ble brakes 20+ times... Air STILL coming out!

if the pedal went to the floor you have a leak, fluid in = air in.

Find the leak first.

All the brake bleeding proceedures are for brake pad jobs, they don't work on system leaks.

 

[bruceb58]

Re: Ble brakes 20+ times... Air STILL coming out!

You have a bad master cylinder. No brake bleeding is going to help you. Air doesn't magically get in a system that is working correctly. Brakes down to the floor means something failed.

 

[fishrdan]

Re: Ble brakes 20+ times... Air STILL coming out!

I also read about the jar trick but I thought it was just to catch the overflow so I didn't use one.

Hose and jar keeps air from being sucked back into the line, I use a piece of clear tube so I can see when the air bubbles are gone.

Haynes says on ABS systems to do the tube in the jar thing and then open the bleed screw and pump the brakes 25 times with the screw open. That sounds counter-productive to me.

Never heard of opening the bleed screw and then pumping the brakes 25 times,,, and then closing the bleed screw. Air can be sucked back into the line every time the pedal is released???

You should have 2 people bleeding the brakes, 1 person on the pedal and 1 person on the bleeder screw.

Pump the pedal 3-4 times and hold pedal firm while the other person quickly opens the bleeder screw, pedal will drop and then close the bleed screw. Repeat until air is no longer coming out or seen in the clear hose, maybe 15-30 cycles. Be sure to check the brake fluid level after every 5-10 cycles or you will be starting all over again if the master cylinder gets sucked dry.

I don't know how the pro's vacuum bleed brakes, but the $25 kit I got was a complete waste of $25 and 2 hours of time. Air kept getting sucked into the lines, even under vacuum... Got my neighbor to pump the pedal and we had them bled in 15 minutes.

Could still be a bad master cylinder, but sounds like the bleeding procedure is bad to me.

 

[CN Spots]

Re: Ble brakes 20+ times... Air STILL coming out!

I bled them normally, not the way Haynes suggested. I'm dreading replacing the mc. It's so far back under the cowl that I have to use a turkey baster to fill the reservoir.

Oh well. I'll swing by tonight and pick up a new one.

Thanks
spots

 

[jonesg]

Re: Ble brakes 20+ times... Air STILL coming out!

I don't see that you ever found the actual leak in all this,

the master cylinder could be good,
you could have a corroded , leaking line anywhere in the circuit.

Unless theres fluid running down the firewall from the MC ?
I'd double check all the lines and unions for fluid.

Put some cardboard down, fill the system, pump the pedal and look for the drops, leave it a few hrs and look for the drips on the cardboard.

 

[CN Spots]

Re: Ble brakes 20+ times... Air STILL coming out!

The entire brake system looks like it just came out of the factory. No visable corrosion or damage.There was never anything on the driveway and the pressure held when the brakes were pumped (engine off). I was all under that thing and never saw any leaks. I cleaned off the booster/mc/firewall yesterday and will check for leaks again. The Admiral sez there's no dough for parts til next week 'less we dig into savings and since she doesn't need the van this week I'll leave it in drydock. It will give me a chance to bang on it with a hammer some more.

 

[ehenry]

Re: Ble brakes 20+ times... Air STILL coming out!

Could be a bad diaphram in the booster.

 

[Gary H NC]

Re: Ble brakes 20+ times... Air STILL coming out!

I vote a bad master cylinder...Have seen it many times where they have internal leakage or leak into the booster.
I agree with Bruce....

 

[thefairlaneman]

Re: Ble brakes 20+ times... Air STILL coming out!

You have a bad master cylinder. No brake bleeding is going to help you. Air doesn't magically get in a system that is working correctly. Brakes down to the floor means something failed.

I agree that the MC is most likely sucking in air.

 

[Numlaar]

Re: Ble brakes 20+ times... Air STILL coming out!

That is a cross diagonal system on that model of Ford... so the problem you are experiencing with the one front and one rear having air is not out of the ordinary...

If I remember correctly, that year also employed a check valve directly below the master that controlled the cross in the system as related to the ABS controller...

Definitely check all of the fittings going to the master, the ABS controller, and the check valves (if it has them) and make sure they are tight.

If it all looks good, then you more than likely have a bad master cylinder, typically it would be the first chamber that goes bad, and would suck air like that... (that would be the line coming off the master closest to the booster). See if it is that side of the circuit that is causing the problem, and if so, go with a new master...

As far as bleeding goes, the pump it up 3-4 times and cracking the bleeder (with two people, one at the pedal one at the wheel) is the proper way to go... also my experience has shown that when you punch a pedal all the way to the floor you blow the master anyways, because the seals ride into a roughened area and usually get a tear in them because they pedal was never meant to go that far down... use care when bleeding it out, and never push the pedal more than half way down! (even with the new master), to avoid damaging the seals. I have seen many newbie techs jump in after changing out a master, and jam the pedal to the floor, which tears the seal, then they are sitting there scratching thier head wondering why they cant get the pedal back...

 

[CN Spots]

Re: Ble brakes 20+ times... Air STILL coming out!

T'was indeed the master cylinder. Rear seal failed allowing air into the back half of the cylinder which controlled the left front and right rear brakes. If someone stumbles across this in the future, check with your parts store in advance... no NAPA or Autozone in the Memphis area had this part in stock and it had to be ordered from out of town. Not rebuildable. Oh, and the only difference in the MCs with Traction Control and without are the dia. of the brake line fittings. 12mm for TCS, 10mm without.

Thanks for the help guys!

spots

 

[adamjr]

Re: Ble brakes 20+ times... Air STILL coming out!

Glad you got it fixed up. Bad engine is a bad time, bad brakes can kill you much easier. There isn't a more sinking feeling then touching the brake pedal and nothing happens.