Soft Brakes

[stever1000]

The wheel/lug nuts hold the drum in place. If the drum isn't fully seated, you might get the slight dragging noise when the brakes aren't adjusted correctly.

-Charlie

Yeah it sounded better after the wheel was on - I figured that was the case but the lug nuts wouldn't seat the drum without the wheel (obviously).

 

[stever1000]

After adjusting the brakes they are more responsive but now the ebrake doesn't hold

The pedal still sinks when stopped at a light - now I'm worried its the master cylinder or booster

 

[flipty]

After adjusting the brakes they are more responsive but now the ebrake doesn't hold

The pedal still sinks when stopped at a light - now I'm worried its the master cylinder or booster

You may need to bleed the MC if you haven't already. It's easy to lose enough fluid during a caliper swap (ask me how I know, I did both sides) to potentially get air in there.

 

[99Runnr]

After adjusting the brakes they are more responsive but now the ebrake doesn't hold

The pedal still sinks when stopped at a light - now I'm worried its the master cylinder or booster

I suggested that awhile back I believe.

I also asked if you could pump the brake pedal up? Put it in park, hold brake pedal, let it sink, release, press, release, press. Does the pedal pressure increase or no change?

 

[stever1000]

With the car on
It feels like there is pressure, but not consistent. If I do what you describe, its soft or spongy at first, then it gets firm, if I repeat it, its soft again then firm, But then if I continue to hold it, it slowly goes further.

With the car off its soft on the first press, then goes firm on the second press and continue to be firm, but I can still press the pedal

No leaks and hoses look okay. Master cylinder looks to be in good shape (on the outside)

I read that rear drum brakes being out of adjustment will cause a low pedal, which many people incorrectly describe as a spongy pedal. But my e-brake works well after a few clicks. I haven't jacked it up yet to rotate the wheels

[MENTION=132328]99Runnr[/MENTION]

I will check again

 

[stever1000]

I can pump it and the pedal still sinks to the floor, even after pumping and holding it will sink

 

[phattyduck]

I can pump it and the pedal still sinks to the floor, even after pumping and holding it will sink

That's a bad master cylinder.

This often happens after brake work (bleeding the brakes). Running the master cylinder piston through its full stroke while bleeding the brakes can damage the seal on the piston. This happens on older brake systems that haven't been flushed regularly.

-Charlie

 

[stever1000]

That's a bad master cylinder.

This often happens after brake work (bleeding the brakes). Running the master cylinder piston through its full stroke while bleeding the brakes can damage the seal on the piston. This happens on older brake systems that haven't been flushed regularly.

-Charlie

The previous owner did the brake job and likely did this at the same time. Oh geez

 

[19963.4lsr5]

That's a bad master cylinder.



This often happens after brake work (bleeding the brakes). Running the master cylinder piston through its full stroke while bleeding the brakes can damage the seal on the piston. This happens on older brake systems that haven't been flushed regularly.



-Charlie

Never heard that before............


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[99Runnr]

Ebay had killer deals when it came to getting a new clutch master and slave cylinder for my 4runner, even compared to Camelback pricing. It was like $80 for BOTH compared to $160 through the discount dealer prices.

Personally, it's one of the parts I would only use OEM for like lower balljoints. Find one on ebay, I'm betting they can be had for the same price as the lifetime warranty crap sold at chain stores.

Bench bleed it, save yourself some hassle there, throw it in, an bleed brakes one more time.

 

[Vansnxtweek]

Subscribed to this. I have been having the same issue for awhile now. Countless hours of bleeding, swapping the master cylinder, and then more bleeding. The same issue you describe still remains. The only thing I can come up with is air still in the master or air in the ABS system.

 

[jkeith.w]

Subscribed to this. I have been having the same issue for awhile now. Countless hours of bleeding, swapping the master cylinder, and then more bleeding. The same issue you describe still remains. The only thing I can come up with is air still in the master or air in the ABS system.

Same here - everything replaced but the ABS pump and lines - still mushy.

Is there a way to cycle the pump while bleeding?

 

[stever1000]

Ebay had killer deals when it came to getting a new clutch master and slave cylinder for my 4runner, even compared to Camelback pricing. It was like $80 for BOTH compared to $160 through the discount dealer prices.

Personally, it's one of the parts I would only use OEM for like lower balljoints. Find one on ebay, I'm betting they can be had for the same price as the lifetime warranty crap sold at chain stores.

Bench bleed it, save yourself some hassle there, throw it in, an bleed brakes one more time.

Thanks I will check ebay - were the discount sellers in the US or overseas?

Subscribed to this. I have been having the same issue for awhile now. Countless hours of bleeding, swapping the master cylinder, and then more bleeding. The same issue you describe still remains. The only thing I can come up with is air still in the master or air in the ABS system.

Did you bench bleed the master?

Same here - everything replaced but the ABS pump and lines - still mushy.

Is there a way to cycle the pump while bleeding?

I believe only Toyota can do it with their special tool. I enquired about it here in Canada and they needed to do the basic bleed ($80) and then diagnosis ($135/hour) since they said it could be a number of things. Bummer

 

[Vansnxtweek]

Did you bench bleed the master?

I did, using the supplied lines and plastic fittings to recirculate the fluid back into the reservoir. To my knowledge all air was out and I continued the process long after I felt it was well bled. What throws me off is that the pedal feels EXACTLY as it did before the master cylinder swap so it leads me to look to other issues. I researched the brake booster but it seems to have nothing to do with this issue. I read a lot about these symptoms but can never find a solid resolution. Sounds like we're in the same boat so hopefully we can figure this out! I'm to the point of using the e brake as an assist when I pull to the end of the driveway in the am because the brakes near about lock up in the rocks when they do all grab at the end of the pedal stroke. It's aggravating.

 

[19963.4lsr5]

You could mash the brakes on stones to get the abs going then try a re bleed. I'm pretty sure I have rust in one of my tone rings up front. Every time I turn sharp right at a slow speed while braking the abs activates.


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[catrains]

The previous owner did the brake job and likely did this at the same time. Oh geez

the previous owner did a brake job whatever that means , because the brakes did not work.

pedal to floor is 1] master is bad 2] leak.. could also be both.. it does not take much of a leak .. and it hot weather the brake fluid evaporates. so harder to find. being old sure can be the master cyl..

if air is in the lines the brake pedal will not drop to the floor it will be a soft pedal and require more pedal pressure to stop as air compresses brake fluid does not so lower brake pressure on the braking components.

 

[stever1000]

You could mash the brakes on stones to get the abs going then try a re bleed. I'm pretty sure I have rust in one of my tone rings up front. Every time I turn sharp right at a slow speed while braking the abs activates.


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This has happened to me twice, in the exact same route into my parking garage there is a hard right turn before I park. Very strange

 

[stever1000]

the previous owner did a brake job whatever that means , because the brakes did not work.

pedal to floor is 1] master is bad 2] leak.. could also be both.. it does not take much of a leak .. and it hot weather the brake fluid evaporates. so harder to find. being old sure can be the master cyl..

if air is in the lines the brake pedal will not drop to the floor it will be a soft pedal and require more pedal pressure to stop as air compresses brake fluid does not so lower brake pressure on the braking components.

I haven't noticed loss of fluid and haven't seen any leaks, even after checking the hoses and connection points. However the truck has 291,000 KM on it, even though the master cylinder looks in great shape!

I will order a new master cylinder from Toyota

 

[stever1000]

I did, using the supplied lines and plastic fittings to recirculate the fluid back into the reservoir. To my knowledge all air was out and I continued the process long after I felt it was well bled. What throws me off is that the pedal feels EXACTLY as it did before the master cylinder swap so it leads me to look to other issues. I researched the brake booster but it seems to have nothing to do with this issue. I read a lot about these symptoms but can never find a solid resolution. Sounds like we're in the same boat so hopefully we can figure this out! I'm to the point of using the e brake as an assist when I pull to the end of the driveway in the am because the brakes near about lock up in the rocks when they do all grab at the end of the pedal stroke. It's aggravating.

That's frustrating you can't find the solution to the problem... I am going to order a new OEM master cylinder and try that...at least if it doesn't work I can cross that off the list

Did you use OEM toyota master cylinder? I have heard of issues with aftermarket replacements straight from the box.

 

[Vansnxtweek]

the previous owner did a brake job whatever that means , because the brakes did not work.

pedal to floor is 1] master is bad 2] leak.. could also be both.. it does not take much of a leak .. and it hot weather the brake fluid evaporates. so harder to find. being old sure can be the master cyl..

if air is in the lines the brake pedal will not drop to the floor it will be a soft pedal and require more pedal pressure to stop as air compresses brake fluid does not so lower brake pressure on the braking components.

Thank you for this information. I did not feel this was an air issue either but I dot know where else to turn. Maybe replace the master again with the chance that the one I get was bad.

That's frustrating you can't find the solution to the problem... I am going to order a new OEM master cylinder and try that...at least if it doesn't work I can cross that off the list

Did you use OEM toyota master cylinder? I have heard of issues with aftermarket replacements straight from the box.

Please report back and let us know if the new master fixes your's up. I wouldn't be surprised if a new one was bad, I've had that experience in the past. Good thinking on that!