Soft breaks?

Tiny
DAWNHILL
  • MEMBER
  • 1990 TOYOTA PICKUP
Brakes problem
1990 Toyota Pickup 4 cyl Four Wheel Drive 154000 miles

I replaced a master cylinder on a 1990 Toyota pickup 4wd std cap and now cannot seem to get all the air out of the front breaks. I benched bleed the master cylinder and can get one squirt of fluid and then nothing. I tried a master bleeder kit on the front break port of the master cylinder and I get the same thing. The master cylinder is a reconditioned, and I have tried two different cylinders. The master cylinder still has the original reservoir on it.
Thursday, November 6th, 2008 AT 1:37 PM

15 Replies

Tiny
JAMES W.
  • MECHANIC
  • 2,394 POSTS
I'm not sure what kind of a "master bleeder kit" you are using. I'm assuming it is a plastic valve screwed into the output port with a hose going back into the resivoir. If this is the case, you need to have one of these on each output port while you are bleeding. Then, leave the tubes in place while you reinstall the master. Disconnect the tube/valve assm. One at a time while you reconnect the brake lines. If the pedal is still soft, you will have to bleed the calipers and wheel cylinders also.
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Thursday, November 6th, 2008 AT 4:03 PM
Tiny
TRISCUIT
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  • 76 POSTS
  • 1986 TOYOTA PICKUP
  • 2.4L
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 125,000 MILES
Hey, here's what's up in summary:

I have bled my brakes multiples times it took me about 4 hours to do so. I did this by pumping the brake pedal 15-20 times then using a breaker bar to hold the pedal down while I went to each wheel to crack the bleeder valve.

I did so in this order: DR, PR, PF, DF, LPSV.

There is no fluid leaking at any lines, hoses or wheels. I did got some gunky fluid from the DR valve and it cleared up fine. I went through the process of pumping the pedal, depressing it, cracking the valve, closing it, then back to pumping the pedal about 4 times/wheel.

The master cylinder never dropped below the minimum fluid line level. I checked it religiously.

I kept my bled brake fluid jar above the bleeder valve height to insure air and fluid flow into the jar without air going back into the line(s).

I get a nice, firm brake pedal when the engine is off and a soft, squishy pedal as soon as it is turned on.

I have adjusted the rear drum brakes to the point where they are slightly difficult to turn by hand when the vehicle is on jacks. I also adjusted my parking brake cable because before doing so my truck would just roll on a steep hill when the handle was completely extended. It now engages and holds the truck nicely within about 5-7 clicks. Wonderful.

My master cylinder was replaced in early 2013 and the truck has accumulated about 5,000 miles in that time so I'm hoping that wear and tear is not an issue. There are also new front brake pads, calipers, hoses, and new rear drums and shoes. There is no fluid leaking on the master cylinder or brake booster when doing a visual inspection.

Lastly, I did do the brake bleeding with the parking brake on which I have since discovered maybe should not be done so I am happy to go back and redo that, but what else am I missing?

Should I look into adjusting my brake pedal height? I'd like highly effective, well-adjusted brakes soon and feel like I may be overlooking something simple.
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Tuesday, July 21st, 2020 AT 5:21 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • MECHANIC
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Hi,

If you pumped the brake pedal and then held it with a breaker bar, that won't work. You really need two people to do this. One pumps the brake pedal and holds pressure on it. Then, one at a time a bleeder is opened while the helper pushes the brake pedal to the floor and holds it until the bleeder is closed. I could be wrong, but based on your description, the brake pedal stays stationary with a breaker bar. Is that the case?

Also, start with the wheel furthest from the master cylinder, right rear. Then left rear, right front, left front.

Here is a link that explains how to bleed and flush the system. You don't need to flush the system, but the directions for bleeding are there.

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

Let me know if this helps or if you have other questions.

Take care,
Joe
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Tuesday, July 21st, 2020 AT 5:21 PM (Merged)
Tiny
TRISCUIT
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Hi Joe, thanks for responding.

I actually bled the brakes both ways just to be thorough. Once leaving the brake pedal depressed with the breaker bar while I cracked the bleeder valve, closed it, then went back to the cab to pump the pedal again.

The second time I would pump the pedal, depress it with the breaker bar, then crack the bleeder valve and go back to the cab to slowly pump the pedal and watch the fluid flow out before using the bar to depress the pedal again and getting out to close the bleeder.

The same goes for the bleed sequence. The first time I did it as you suggested and the second time I looked up the sequence specific to my truck and did it that way. The researched sequence is the one I listed in my original posting.

I still have spongy brakes. :P
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Tuesday, July 21st, 2020 AT 5:21 PM (Merged)
Tiny
JACOBANDNICKOLAS
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I have never done it that way. So when you depressed it to the floor with your foot, you held it to the floor with the breaker bar?

I noted that the calipers and other components were replaced. Was that at the same time as the master cylinder? When you say a spongy pedal, how far down does the pedal go?

Joe
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Tuesday, July 21st, 2020 AT 5:21 PM (Merged)
Tiny
TRISCUIT
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You've never done it which way, with:

A) The pedal depressed to the floor, bleeder cracked, closed, then breaker/some object removed.

B) With the pedal depressed to the floor, bleeder cracked, pedal pumped slowly several times then held down by the breaker bar, bleeder closed?

Yes, one of the ways I tried was to pump the pedal slowly, depress it, then use a breaker bar to hold it down while I went under the truck either open or close the bleeder depending upon where I was at in the sequence.

The pads, calipers and hoses were replaced before the Master Cylinder, but not too long before. The Master Cylinder, was professionally replaced. The drums, shoes, and wheel cylinders were replaced years later.

The pedal doesn't go all the way to the floor, thankfully. If I stomp on the pedal I don't get a nice stiff pedal that "slams" on the brakes. No, rather the brake pedal will travel into the "squish zone" and soggily hit it's end point where it is most firm. During this time the truck is lazily stopping. There's no screeching, nosedive from a sudden stop. Instead I'd hit whatever was in front of me if it came to that = no bueno. It feels like the pedal travels for too long before the brakes begin to engage and then the stopping power is still not as strong as it should be.

I was out bleeding again today, same result. I did it with the parking brake off this time. I did notice that when I'm near the end of the pedal's travel I hear something in the rear at what sounds like one of the wheels. Squeaking (?). It's not a squeal or a true squeak but that's the closest I can describe it. It's clear. Wish I could send a recording.

I just don't want to take it to a shop to have them tell me what would be the brake equivalent of "Oh, you ran out of gas. That's all." If it's something super simple I'll be really irked. Lol
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Tuesday, July 21st, 2020 AT 5:21 PM (Merged)
Tiny
JACOBANDNICKOLAS
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Hi,

I have never held the pedal down with a tool and then jumped out to close the bleeder. I always have closed the bleeder as soon as the pedal reached the end of it's travel and fluid started slowing down. I'm just wondering if somehow, air is getting back in between the time you secure the pedal and get to the bleeder. It's actually an ingenious idea. I just have never done it.

If you pump the brakes several times, do you get a more solid pedal that will stop the vehicle quicker?

The noise you hear is commonly caused by a lack of lubrication between the shoe and backing place (where the shoe touches the backing plate).

Also, I want you to try one other thing. Adjust the brakes until you feel a drag. Then, get in the vehicle and apply the brakes several times to center the shoes and readjust. Between the brake drum and brake shoe, there should be.024" which is minimal. See pic 1

Joe
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Tuesday, July 21st, 2020 AT 5:21 PM (Merged)
Tiny
TRISCUIT
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Hey Joe,

Just sending a check-in note. I've been busy and although I've been out working on the brakes my truck is a 1-ton dually and has a free floating rear axle. Taking the drums off is a PITA and requires me to remove the axle on each side - I'm getting there. Between that and attempting to back off the shoes by way of the star wheel (which I'm terrible at and always have a very difficult time finding an releasing the arm that holds the star wheel in place) it's taking me a minute. I'll send another update soon.
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Thursday, July 23rd, 2020 AT 10:07 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,643 POSTS
This video can help with the job on a similar rear end:

https://youtu.be/EMxfb9X3ywE

Please run down this guide and report back.
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Friday, July 24th, 2020 AT 11:47 AM
Tiny
TRISCUIT
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Alright, I finally had time to remove the axle shafts, bearings and lock nuts so I could get the drums off of the rear. I turned the star wheel completely and started measuring as best I could to get close to the right amount of tightness. I don’t have a brake caliper tool but worked at it. I'm never entirely sure how much drag there is supposed to be. I’ve watched some more videos but it’s hard to know how “easy” it should be to be able to turn each wheel by hand with the drum installed. I’ve been listening for shoe drag and it seems okay.

I got in the truck and pumped the brake pedal several times for each drum/shoe adjustment. Before beginning the shoe adjustment I loosened the parking brake nut on the cable so that I could go back and readjust that as well once the shoes and drums are done. I also pulled up on the parking brake a few times after each adjustment. Last thing I did was turn the engine on and pump the brake to see if the pedal feels and different.

Should I keep tightening the shoes? The wheels are still pretty easy to turn and I can do it with one hand. The other thing I’ve observed is that the driver’s side drum gets harder to turn then easier to turn while spinning the drum. The drums and shoes are all new. Is this something to be concerned about?
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Tuesday, August 4th, 2020 AT 5:17 PM
Tiny
KEN L
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Does the emergency brake seem to work good? If so the shoe adjustment is correct. How does the brake pedal feel? Can you please shoot a quick video with your phone so we can see what's going on? That would be great. You can upload it here with your response.
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Thursday, August 6th, 2020 AT 10:43 AM
Tiny
TRISCUIT
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Hi Ken, the brake pedal is wonderful when the engine is off and then gains travel distance and loses firmness when the engine is turned on. Here is a video I just made for you to reference, as requested.
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Thursday, August 6th, 2020 AT 5:16 PM
Tiny
KEN L
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The video was great thank you. Everything looks normal to me. When you start the engine vacuum is helping the brake pedal move downward which is normal, the brake shoe adjustment looks good as well as the e brake handle movement. When you drive it does the brake seem to work okay?
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Saturday, August 8th, 2020 AT 11:56 AM
Tiny
TRISCUIT
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I just finished taking the truck for a spin around the neighborhood and the brakes are much better. I forgot to test the emergency brake on some of the steep hills but if it's out of adjustment that's an easy fix since the rears are good to go. Thanks for all of the help! It's appreciated.
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Monday, August 10th, 2020 AT 6:25 PM
Tiny
KEN L
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Nice work, we are here to help, please use 2CarPros anytime.
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Tuesday, August 11th, 2020 AT 4:32 PM

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