09-24-2019, 08:24 AM
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#1
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Junior Member
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Join Date: Nov 2014
Location: Northern VA
Posts: 29
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Junior Member
Join Date: Nov 2014
Location: Northern VA
Posts: 29
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Mushy brakes
Hello Everyone.
The brakes on my 4Runner seem to have gone really mushy recently. I have been searching throughout this forum (and others) to see how best to troubleshoot this.
There seems to be a good amount of distance, when I press on the brake pedal, before the brakes actually start to catch. It was not like this a few months ago, and it seems like it has gotten worse. From what I read, it sounds like if I replace the entire master cylinder/abs pump assembly, that should fix it. But I am not ready to spend $2k on it yet.
I see some Toyota part sites sell the master cylinder separately from the abs pump assembly. I am wanting to replace the abs pump assembly and/or just the accumulator (since it is cheaper than the MC). I am not sure if it is the problem.
I can hear the pump turn on when I first start up. And it cuts off after maybe 5-7 seconds. But when I press on the brakes, they feel really mushy. If I hit the brakes 3 times in a row, the pump comes back on (is that normal?).
Could it be just the accumulator leaking? How many time should I be able to hit the brakes before the pump starts again?
Thanks,
JT
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09-24-2019, 10:13 AM
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#2
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Member
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Join Date: Mar 2018
Location: Moorpark CA
Age: 42
Posts: 479
Real Name: Elliott
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Member
Join Date: Mar 2018
Location: Moorpark CA
Age: 42
Posts: 479
Real Name: Elliott
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Quote:
Originally Posted by JTS197
Hello Everyone.
The brakes on my 4Runner seem to have gone really mushy recently. I have been searching throughout this forum (and others) to see how best to troubleshoot this.
There seems to be a good amount of distance, when I press on the brake pedal, before the brakes actually start to catch. It was not like this a few months ago, and it seems like it has gotten worse. From what I read, it sounds like if I replace the entire master cylinder/abs pump assembly, that should fix it. But I am not ready to spend $2k on it yet.
I see some Toyota part sites sell the master cylinder separately from the abs pump assembly. I am wanting to replace the abs pump assembly and/or just the accumulator (since it is cheaper than the MC). I am not sure if it is the problem.
I can hear the pump turn on when I first start up. And it cuts off after maybe 5-7 seconds. But when I press on the brakes, they feel really mushy. If I hit the brakes 3 times in a row, the pump comes back on (is that normal?).
Could it be just the accumulator leaking? How many time should I be able to hit the brakes before the pump starts again?
Thanks,
JT
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I would replace the brake fluid first. Easier and cheaper. Plus, contaminated brake fluid will cause braking power to suffer dramatically.
__________________
2007 SR5 V6 4WD 205k, Titanium Metallic. 5100s, OME 885/895, extended rear links, ST Maxx 255/75 R17 on 17x8s, mud flap delete,TB spacer, Spectre CAI, DRL delete, HCF delete, DAC delete, K&N cabin filter, TPMS bypass, Fog light mod, USB galore, dash cam, LED lights all over, rear bumper lights, cbi ditch light brackets w/lights, atrac off, OBA w/2 gallon tank/hidden hook up, Trailgear welded sliders, Rocksteady skids, custom swing-out, 3⁰, SE hood w/working vent, Sprint booster, JET MAF, Kenwood TM-V71a w/motorized antenna, custom dual battery, custom roof rack/lights, custom TRED mount, external 12v, rear diff breather, pck, Freedom UCAs, custom stereo, Aluminum rad, trans cooler, 240A alternator...for now...
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09-24-2019, 02:01 PM
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#3
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Senior Member
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Join Date: Oct 2013
Location: illinois
Posts: 1,597
Real Name: Ron
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Senior Member
Join Date: Oct 2013
Location: illinois
Posts: 1,597
Real Name: Ron
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Yes, I would try easy things first. Bleed all the brakes extensively, fill a baby food jar from each caliper.
Check your pads for wear.
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09-24-2019, 04:56 PM
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#4
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Member
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Join Date: Dec 2008
Location: Burnaby, BC
Age: 38
Posts: 408
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Member
Join Date: Dec 2008
Location: Burnaby, BC
Age: 38
Posts: 408
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I had issues in... all the calipers... with some combination of pistons being jammed in some way or another on every single caliper. And the brake pedal had all the feel of mashed potatoes.
Likely that it took substantially more force to move the pads onto the disks, so it'd take alot of brake pedal force to engage the brakes.
Yeah, so lesson learned there was CENTRIC is bad, mmmkay.
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09-24-2019, 05:51 PM
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#5
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Senior Member
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Join Date: Nov 2016
Location: South Carolina
Posts: 4,618
Real Name: Skip
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Senior Member
Join Date: Nov 2016
Location: South Carolina
Posts: 4,618
Real Name: Skip
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Quote:
Originally Posted by JTS197
Hello Everyone.
The brakes on my 4Runner seem to have gone really mushy recently. I have been searching throughout this forum (and others) to see how best to troubleshoot this.
There seems to be a good amount of distance, when I press on the brake pedal, before the brakes actually start to catch. It was not like this a few months ago, and it seems like it has gotten worse. From what I read, it sounds like if I replace the entire master cylinder/abs pump assembly, that should fix it. But I am not ready to spend $2k on it yet.
I see some Toyota part sites sell the master cylinder separately from the abs pump assembly. I am wanting to replace the abs pump assembly and/or just the accumulator (since it is cheaper than the MC). I am not sure if it is the problem.
I can hear the pump turn on when I first start up. And it cuts off after maybe 5-7 seconds. But when I press on the brakes, they feel really mushy. If I hit the brakes 3 times in a row, the pump comes back on (is that normal?).
Could it be just the accumulator leaking? How many time should I be able to hit the brakes before the pump starts again?
Thanks,
JT
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From your description your pump is working as it should, I would do as the others have mentioned and check the rest of the system, especially flushing out the old brake fluid and replacing with new fluid, but first check to make sure that all of your calipers are working correctly and not seized or partially seized, replace any that aren't working as they should.
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2004 Limited V8
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09-24-2019, 10:45 PM
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#6
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Senior Member
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Join Date: Dec 2018
Location: New Hampshire
Posts: 1,177
Real Name: Mike
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Senior Member
Join Date: Dec 2018
Location: New Hampshire
Posts: 1,177
Real Name: Mike
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Front calipers fixed mine, I did do the rotors and pads at the same time.
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Mike
03 4runner Limited
1GR-FE V6 w/199k miles
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09-25-2019, 01:01 AM
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#7
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Junior Member
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Join Date: Mar 2019
Location: East Bay, California
Posts: 11
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Junior Member
Join Date: Mar 2019
Location: East Bay, California
Posts: 11
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Same mushy feeling here, both front calipers had frozen pistons. Changed pistons, bled the lines and all is good!
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09-25-2019, 07:40 AM
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#8
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Junior Member
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Join Date: Nov 2014
Location: Northern VA
Posts: 29
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Junior Member
Join Date: Nov 2014
Location: Northern VA
Posts: 29
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Thanks everyone. I know the front calipers were changed maybe 80k miles ago; sounds like I need to check them again.
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09-25-2019, 10:51 AM
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#9
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Member
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Join Date: Mar 2018
Location: Moorpark CA
Age: 42
Posts: 479
Real Name: Elliott
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Member
Join Date: Mar 2018
Location: Moorpark CA
Age: 42
Posts: 479
Real Name: Elliott
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All the seizing calipers are a result of bad brake fluid. Water ingresses the fluid, which in addition to making your braking power suck eggs, corrodes the inside of the caliper and piston until it seizes. I think Toyota recommends changing brake fluid like every 2 or 3 years, I remember reading somewhere. Fluid is ALWAYS cheaper than iron. Ounce of prevention vs pound of cure...ok I'll get off my soap box now lol
__________________
2007 SR5 V6 4WD 205k, Titanium Metallic. 5100s, OME 885/895, extended rear links, ST Maxx 255/75 R17 on 17x8s, mud flap delete,TB spacer, Spectre CAI, DRL delete, HCF delete, DAC delete, K&N cabin filter, TPMS bypass, Fog light mod, USB galore, dash cam, LED lights all over, rear bumper lights, cbi ditch light brackets w/lights, atrac off, OBA w/2 gallon tank/hidden hook up, Trailgear welded sliders, Rocksteady skids, custom swing-out, 3⁰, SE hood w/working vent, Sprint booster, JET MAF, Kenwood TM-V71a w/motorized antenna, custom dual battery, custom roof rack/lights, custom TRED mount, external 12v, rear diff breather, pck, Freedom UCAs, custom stereo, Aluminum rad, trans cooler, 240A alternator...for now...
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