mashed on the brake pedal for a normal stop and the pedal went to the floor

Have tried rebleeding? These guides can help you fix it.

https://youtu.be/w7gUsj2us0U

and

https://youtu.be/WDxvEQrMkBg

and

https://www.2carpros.com/articles/brake-pedal-goes-to-the-floor

Please run down this guide and report back.

thanks for the guides fix it for me this site is wonderful!

Thanks

my brakes seem to be spongy. when i press the brake i can hear a swish sound. they stop fine . the sound has just started over the weekend. when i turn off the truck and take a little pressure off the brakes the pedal comes up and gets hard. it's as if it is full of air. i had a brake job done about a year and half ago. i changed the booster about two years ago.

Check brake master cylinder fluid level if okay-try bleeding the brakes don't work-do below Get the vacuum hose to the brake booster, check valve and brake booster checked out-sounds like its leaking. These guides can help you fix it.

https://youtu.be/w7gUsj2us0U

and

https://youtu.be/WDxvEQrMkBg

and

https://www.2carpros.com/articles/brake-pedal-goes-to-the-floor

I am not getting fluid to the front left brake caliper. I pulled the valve from the brake module and not getting any fluid out of it either. I get fluid to all three other corners with no issue. Do I need to replace the brake module as I have replaced the master cylinder already?

Do you mean the ABS brake module? you are not getting any fluid out of or do you mean the caliper itself? I would check the bled valve they can clog up

Just on of the valves on the ABS module where it goes to the left front.

Sounds like the solenoid may be stuck closed inside the ABS module. Have you tried unplugging the electrical connector to the module? that will tell you if the solenoid is staying energized or if its just stuck closed. The solenoid should be open unless the ABS unit is energized. As you said the others are bleeding okay.

So if I unplug how do I know if it is stuck or open?

well if it is stuck closed you still wont get any fluid through it. You are getting fluid through the others, so they are open. They should be normally open unless the ABS is needed to prevent the tire from locking up and causing the vehicle slide. The ABS pulses the braking system to prevent lock up under slippery conditions.

I would also use fresh brake fluid, hopefully there is not something stuck in the solenoid itself.

Also, could be air in module preventing the fluid from coming out, which method did you use to bleed the system? Have you tried pushing the brake peddle gently with the line open to see if any fluid will come out or have you just gravity bled it?

It can be very difficult to get air out of the ABS system considering how many areas air can get stuck in there.

have a professioanl use their scanner to open ABS unit and bleed system properly.

Took a bit to get to this point so I hope it is real and not some other thing to join. I was led here by a post that described my problem exactly but never gave the solution. 1993 2wd Silverado, squishy low pedal. New pads and shoes and master cylinder, same problem. I push the pedal fast and there is a whoosh sound and almost normal pedal. Brake normally and it starts braking around half way down and will go to the floor if low and slow pressure is applied.

Squishy low pedal is 95% of the time air in the lines. The description of stomping the pedal and they feel better bears that out. It is trapping more fluid in the bore of the master cylinder. Those lines have a bunch of high spots that trap air. The other times it is a failed brake part like a bad rubber line or mis-adjusted set of brake shoes. These guides can help you fix it.

https://youtu.be/w7gUsj2us0U

and

https://youtu.be/WDxvEQrMkBg

and

https://www.2carpros.com/articles/brake-pedal-goes-to-the-floor

You say you did the pads and shoes, did you replace the drums as well?
If not you might want to pull them, measure them for wear on the inner area and the area close to the backing plate, they can wear in the shape of a bell. When you step down the brake shoes end up flexing sideways and you get a poor pedal response.

I’ve been doing everything i have read on here and checked the repair guides and nothing. i got new master cylinder, new brakes all around(rotors drums, pads, shoes), new booster, bled brakes in sequence, new brake lines i believe i have done everything and still spongy.
I used up like 3 big bottles trying and trying .

Hi,

If you have no leaks and it is doing the same thing with a new master cylinder, my first thought is are the rear brakes (drum brakes) properly adjusted. Does it have rear drum shoes? If so, how were they adjusted?

Let me know.

Joe

Good evening,

Convention bleeding on a truck rarely works. There is not enough pedal push to get the air out.

you need to power bleed the system. That is where you attach a cover to the top of the master cylinder and the air is applied to the master. Then you open the bleeders in sequence until the air is gone.

a side note. If you have ABS, you will need to do the other procedure I attached as well. Convention and pressure bleeding does not get the air out of the ABS unit.

Roy

Pressure Bleeding

Note: The pressure bleeding equipment must be of the diaphragm type. It must have a rubber diaphragm between the air supply and the brake fluid to prevent air; moisture, oil, and other contaminants from entering the hydraulic system. Also adapters are needed. depending on the type of master cylinder used.

Tools Required:
J-29567 Brake Bleeder Adapter (Plastic Reservoir)
J-35856 Combination Valve Depressor

Note: It is very important that the correct master cylinder bleeder adapter be used to avoid possible damage to the master cylinder reservoir.


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1. Fill the pressure tank at least 1/3 full of brake fluid. The bleeder must be re-bled each time fluid is added.
a. Charge the bleeder to 140 - 170 kPa (20 to 25 psi).
2. Use J-35856 to depress and hold the valve stem on the combination valve during the bleeding operation.


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a. Install the bleeder adapter so the leg with the release valve is towards the cowl.
3. Bleed each wheel in the following sequence.
a. Right rear
b. Left rear
c. Right front
d. Left front
4. Connect the hose from the bleeder to the adapter at the master cylinder.
a. Open the tank valve.
5. Attach a hose to a brake bleeder screw.
a. Immerse the opposite end of the hose into a container partially filled with clean brake fluid.
6. Open the bleeder screw at least 3/4 of a turn and allow the fluid to flow until no air is seen in the fluid.
a. Close the bleeder screw.
7. Repeat step six at all the wheels.
8. Open the bleeder screw on the Isolation/Dump Valve (vehicles with power brakes only).
a. Allow the fluid to flow until no air is seen in the fluid.
b. Close the bleeder screw.
9. Check the brake pedal for "sponginess", repeat the entire bleeding procedure if this condition is found.
10.Remove J-35856.
a. Disconnect the line from the bleeder adapter.
b. Remove bleeder adapter.
11.Fill the master cylinder to the proper level with brake fluid.

Did you reply? I got an email but nothing came up.

roy

Having problem with brakes. Replaced brake booster, brake lines, pads, master cylinder. Still have no brake pedal. How do I fix the problem. This is for a 1990 Cheverolet K1500 5.7 Silverado.

Follow this procedure to bleed brakes;

https://www.2carpros.com/articles/how-to-bleed-or-flush-a-car-brake-system

Also if you have ABS brakes the unit must be held open while bleeding the system if not bunch bleed the master cylinder before installing it.

https://www.2carpros.com/articles/how-to-replace-a-brake-master-cylinder

To do this, get a large soda bottle and some clear hose that fits the bleed nipple snugly from your local hardware store.

Fit one end over the bleed screw and run the line higher than the bleed screw then into the bottle. Put a little axle grease on the threads and once you get some of the air out, you can just keep flushing fluid without stopping to hold and release and tighten bleed screw. Since you have so many issues, I would suggest flushing it until it comes out clean.

Starting at the right rear caliper, (This is the farthest from the master cylinder and needs to be done first.)Pump and hold but you can also just pump if the level in the master cylinder is dropping. It takes a while to get fluid going from such a far place especially with a new caliper. To create the pressure to get the fluid going, it has to fill a large cavity the the master cylinder is not designed for. The master cylinder only moves a little bit of fluid when you use your brakes...so be patient, it will come.
If the pedal gets hard to pump, there is contamination somewhere and is often in the bleed screw. Remove it and clean it out.

Now move on to the drivers' side rear brake. Then the passenger side front brake . Then lastly the drivers front brake.

This system of working farthest away from the master cylinder to the closest helps remove the most contamination and helps more fluid to move along.

ALSO, never let the master cylinder get below the low mark. that will pump air into the brakes. If you think bleeding the farthest caliper is hard, a master cylinder is a killer to bleed.

Hey SILVERADO-GAR

Here is a guide that will help you fix the problem

https://www.2carpros.com/articles/brake-pedal-goes-to-the-floor

Please let us know happens so it will help others.

Best, Ken

I had a bad rear brake line, changed it, wheel cylinders, shoes and spring kits. Also changed the master cylinder. Bled the brakes three times (yes, I know how) still no rear brakes. Bleeding process went as planned with fluid squirting as it should. Bought the tool to hold the proportioning valve centered. Still no rear brakes. Could the proportioning valve be bad?

Good afternoon,

It sounds like you still have air in the system.

I would rent a pressure bleeder, not a vacuum bleeder, and force out all the air in the system. With the length of the truck, it is difficult to get all the air out.

https://www.2carpros.com/articles/brake-pedal-goes-to-the-floor

Roy

One other thing, the "Red Brake Light" is now on the dash, it lit up after the bleeding process...It was never on prior to that. Could you share the bleed order if you have time. We did Right Rear then Left Rear then Right Front then Left Front. We also bench bled the master before installing. Is there something else? There is no fluid leaks anywhere as well. Thank you in advance.

Hello my name is Dave.

I have found an easier way to bleed the brakes is to put a little brake fluid in a bottle, just enough to cover the tip of a small hose (I usually use a 16 once water bottle). Next get a few feet of 3/16" washer fluid hose and attach it to the bleeder valve and put the other end in the fluid in the bottle. Open the bleeder and have someone pump the brakes until the the bubbles stop, no need to open and close the valve just leave it open. When the bubbles stop have your helper hold the pedal to the floor and close the valve.Do this starting at the wheel furthest from the master cylinder working your way towards it. This procedure will insure no air is the system. The other thing I was wondering is if you have adjusted the rear brakes, I would make sure they are adjusted prior to any bleeding process. I hope this helps you get your brakes working properly and if you need further assistance please feel free to come back and update us and thank you for using 2CarPros!

As far as the red light, make sure the fluid level is correct. If that is okay, then the proportioning valve has moved to one side.

Usually just pushing down hard on the brake pedal will reset the valve. If not, then the valve may be stuck.

Roy

I stopped at a red light today and my brake pedal went to the floor. I can slow the truck down abit but lost alot of the brakes. I checked the break fluid and the back silinder was low. what do I need to do now to repair the breakes? when I step on the brakes I can hear some air sound.

You have blown a brake line. Because of the year, chances are one of the steel lines has rusted and leaked. Check all brake lines and lines for leaks. If they are all good, and I doubt they are, check rear wheel cylinders and front calipers for problems.

Also, refill the master cylinder and see if after pumping the brakes it goes low again. It should and you should see brake fluid in the area of the leak.

Let me know what you find.