30th t/a

iTrader: (51)

I bled the brakes, fluid shoots out. no air. when I drive it the pedal goes to the floor before it stops. The resivoir is full of fluid and I dont see any leaks.

things to note:
1. I had ALL of the calipers off the car to paint.


where do I start looking?

thanks

dragonrage

Likely brake booster related.

Marc 85Z28

iTrader: (8)

Did you electronically bleed the ABS HCU?

Next time you have the calipers disconnected install some vacuum caps over the brake lines to prevent all the fluid from leaking out and causing this problem.

30th t/a

iTrader: (51)

no i didnt electronically bleed the ABS HCU. Do I need to? I never heard of that.

dragonrage

Well, depends on why you're bleeding the brakes. But I'm not sure it would act up all the time like this... If the thing's always in the circuit then it could be bled normally... The whole reason it's a pain to bleed is that it's not always in the circuit...

jclz28

If you emptied the master cylinder while bleeding the brakes, you will need to have the electronically bleed the ABS HCU. If you didnt, you still have air in the calipers. Try gravity bleeding all of them, adding fluid to the master as you do it. You will probably need to run about a quart of nice fresh brake fluid thru the master. Then hit the calipers a few times with a rubber mallet to dislodge any trapped air. Then do the standard bleed thing, right rear working to left front. BTW, you may want to close the bleeder BEFORE the pedal hits bottom. Seems to help get a pedal faster...

dragonrage

If you need to electronically open the ABS unit solenoids to get air out, then you would have needed to do the same to get the fluid out.

Marc 85Z28

iTrader: (8)

That is incorrect.

30th t/a

iTrader: (51)

The matser cylinder was full of fluid the ENTIRE TIME.
After doing some research and having my uncle, whos has been a certified mechanic for 20+ years look at this situation, replacing the master cylinder seemed to be the answer to the problem.....so I bought a new master cylinder, bench bled it and installed it. Guess what.....It wasnt the answer. Theres $110 out the FN window.

Would I still need to gravity bleed the brakes even though I bled them 4 different occasions and NO air comes out??


NO ABS LIGHTS COME ON EITHER

1 FMF

iTrader: (1)

i had all 4 calipers off my car last winter to polish them, they were off for about 1-2 months. Very little fluid will come out of the lines at the caliper end so it's really no big deal.
If you didn't touch the master cylinder, then i would say get some earl's solo bleeds and install them on each caliper. that makes it very easy to bleed the calipers, although it's best to have 2 people still- 1 pumping the brake pedal the other keeping the master cylinder topped off and checking the flush at each caliper. I went through 2.5 quarts of fluid to bleed my system to where i got clean fluid out at each caliper, and would estimate about a quart to just fully flush the air out of the calipers.

since you replaced the master cylinder, there's a chance you could have introduced some air into the ABS unit, which is now another problem on top of the previous one. I'm not familiar first hand with replacing the master because i haven't done it. my advice now would be to still get the earl's solo bleeds, will cost like $20 total for 4, and just bleed the **** out of the system. It may be your procedure of opening/closing the caliper bleed screw caused air to keep getting in there. The other solution is take it to a brake shop, or buy a pressure bleeder yourself but they're a few hundred bucks, they connect on top of the master cylinder with a few quarts of brake fluid pressurized and force fluid through the system, so all you do is open each caliper bleeder and watch air/fluid come out. And if that doesn't do it, then use the pressure bleeder method and also get a code scanner/autotap/or go to dealer to where you can command the PCM to activate the ABS unit brake bleed procedure- that will cycle the ABS unit valves as you force fluid through it to purge out the air.

and what is this gravity bleed ****? If gravity is pulling the fluid out, then the fluid is flowing DOWNWARD and the ******* air bubble is going to stay in the system floating upward through the fluid. that is way you have to force the brake fluid through the system, to push the air out the caliper bleed screw which is at a lower point.

Also make sure you installed your calipers correctly, they should be oriented on the car where the bleeder valve is on top. If the caliper is oriented where the bleeder valve is on the bottom side you'll never purge the air out.

cambirdracing

iTrader: (4)

Have it towed it to a brake shop and pay them to pressure bleed it with a machine. They put pressure to the m/c, pressurize it and bleed at each wheel.

30th t/a

iTrader: (51)

Well I took the master cylinder back and got my money back.

Thanks for the good info 1FMF. I bled the system alot. Fluid sprays out so to me it looks like its fully bled

Cambirdracing....Im about ready too but I hate to get raped by the stealership....I mean dealership.

1 FMF

iTrader: (1)

when you bleed the brakes, is the engine running or off?

with engine off and no bleeder valves opened, when you pump the brake pedal numerous times to get rid of all the vacuum supplied by the brake booster, will the pedal firm up and eventually build up pressure or will the pedal consistently go to the floor easily?
Brake bleeding is not rocket science, ever see some of the people working at brake shops? i wouldn't bring it anywhere yet, unless you can't afford the down time.

30th t/a

iTrader: (51)

The engine is off when I bled the brakes.
The pedal will get firm if I continuosly pump it but as soon as I let off the pedal and step on the pedal again, it goes right to the floor.

Ive bled brakes LOTS of times. Thats why im so frustrated. Something so simple and easy giving me this much bullsh*t.

Im going to buy a couple quarts and going to bleed each brake line until I have used almost the complete quart. Maybe I got air trapped in the middle somewhere.

Marc 85Z28

iTrader: (8)

Again, you need to electronically bleed the HCU. Find someone with a Tech II and properly bleed the system.

Kevin01Z28

iTrader: (8)

I bled my entire system with the engine off and car on jack stands. Wasnt a drop of fluid in the lines, calipers, or master cylinder to begin. I opened all four bleeders on the calipers, loosened every line at the abs unit, and began filling system. I started at the top and when i saw a steady stream of fluid come from the fitting i tightened it and moved to the next working my way down to the bleeders on the calipers.

Then had a friend pump the brakes and hold the pedal while i bled one wheel at a time. Did that till no more bubbles were present.

If your brake booster is bad it will require more effort to stop but shouldn't fade. You may have a bad master cylinder if your system is properly bled and you get pedal fade or it goes all the way to the floor.

dave5514

iTrader: (5)

Same thing happened to me. I took my calipers off to have painted, had small bags on the lines (I should have plugged them, but such is life).

What you need to do is bleed the brakes in this sequence: RR, LF, RF, RR. I highly recommend using a pressure bleeder such as a Motive powerbleeder or a like type. Makes it SO much easier.

Here is a key point, before bleeding the ABS module has to have the front and rear displacement cylcinders in the topmost position. GM uses a Tech I scanner to 'rehome the pistons'. Here is how you can do this without a Tech I:

Have the car on jack stands, turn the key to the on position (power but NOT started), put the tire on the front right hub, and spin it. You need to get the system think it is going above 5 mph (you don't have to spin it very hard) and you will hear the ABS module cycle. Turn the key to the off position and start the bleeding process. Should be good to go. Also, tap the calipers with a rubber mallet (not hard) as you are bleeiding them as it helps displace trapped air bubbles.

I did this procedure twice on mine (I was also replacing the entire systems fluid) so I wanted to make sure I got all the old stuff out. It was easy to see using the blue fluid.

Hope that helps.

30th t/a

iTrader: (51)

Ok I went and bought a used, low mile booster and another master cylinder just that way I know I can eliminate those out of the equation.

We rebled the brakes and we rebled the ABS thing. Now with the car OFF, the 1st push of the pedal, it goes right to the floor, then every push after that the pedal feels perfect....thats with the car off.
With the car ON...the pedal goes to the floor EVERYTIME.

Im taking it somewhere to have the brakes electronically bled.

PAGregSS

iTrader: (10)

You don't need to take it anywhere to bleed the ABS block. Put the rear up on jack stands and put the car in gear. You need to only spin the car up until you reach 6 mph, then apply the brakes. This will open the ABS block. Leave the car running and bleed the brakes as it will leave the ABS block open. Learned this many years ago.

30th t/a

iTrader: (51)

The car is already at Tom Henry Chevorlet and for some reason I have ZERO brakes now. They werent able to electronically bleed the ABS because I removed the TCS module thing and the guy said I need that on the car because by NOT having that it lead to a fault in the scanner. Im getting that part tomorrow and hopefully they will be able to complete the job.