spongey brake pedal

[Tog]

so I'm 400km into a 510km trip in the outback of nowhere and the brake pedal goes almost to the floor. Stop and check heaps of fluid still about 8mm of meat on the pads no excessive heat from any wheels so I don't think a caliper is jammed. Any suggestions what may be wrong???

2004 3.7 limited

 

[JasonJ]

Typically that only ever happens when you have a leak, or air is introduced into the system. It could also be that the master cylinder seals have failed and it is leaking internally, such that when you press the pedal, the pushrod moving in the master cyl is not actually generating much force.

How does it stop? I imagine not very well.

 

[renegade 04]

Try bleeding them and see if it helps. I had a similar issue and I had to bleed the brakes a few times.

 

[Tog]

doesn't stop well but it does stop. no signs of a leak and the fluid levels are the same after 500km as they were before I started. Air was my thought unfortunately I don't have equipment with to try and bleed.

2004 3.7 limited

 

[Charlesthe2nd]

Are you going to be able to make it home or will you need to fix it on the trail?

 

[LibertyTC]

The is a whole section in the factory manual about testing- this is for base or non-ABS
From manual-
"If a low pedal is experienced, pump the pedal several times.
If the pedal comes back up worn linings or rotors are the most likely causes.
The proper course of action is to inspect and replace all worn components.

A spongy pedal is most often caused by air in the system.
However, substandard brake lines and hoses can also cause a spongy pedal.
The proper course of action is to bleed the system, and replace substandard quality brake hoses if suspected"

 

[J33Pfan]

so I'm 400km into a 510km trip in the outback of nowhere and the brake pedal goes almost to the floor. Stop and check heaps of fluid still about 8mm of meat on the pads no excessive heat from any wheels so I don't think a caliper is jammed. Any suggestions what may be wrong???

2004 3.7 limited

some things to think about..

Is the brake fluid too hot?

Are the calipers clogged with dirt/mud?

Is the fluid failing? Change the fluid, maybe go synthetic.

Are your brake hoses dried/restrictive. RnR Hoses when you get back.

As mentioned, Master Cylinder not working effectively.

You may not be leaking now, but there's a good chance air got into the system.

 

[Tog]

that's a real good question. At the moment it is still driveable it does stop just not super quickly. I am noticing a scrubbing noise coming from what sounds like the front left heard mostly on left turns could be caliper drag or maybe wheel bearing. Dunno if a bearing would affect the brakes though.

2004 3.7 limited

 

[ltd02]

Can you pull the wheel and have a look? Does it pull when you do brake? wonder if you just have something jammed in there so the caliper won't slide.

 

[Phil + Neela]

that's a real good question. At the moment it is still driveable it does stop just not super quickly. I am noticing a scrubbing noise coming from what sounds like the front left heard mostly on left turns could be caliper drag or maybe wheel bearing. Dunno if a bearing would affect the brakes though.

2004 3.7 limited

I just replaced my left front caliper last week because it seized on me. It never made a noise, but my brake was spongy on my drive home after picking up wood for a project. When I pulled into my driveway, my wheel was radiating heat and smelled of burning pad material.

If you’re boiling fluid (seized caliper), then the sponginess should go away after it cools down. If it doesn’t, then it’s most likely what everyone is saying: air in the lines or bad master cylinder.


Sent from my iPhone using Tapatalk

 

[daves06lrenegade]

If you have antilock brakes (ABS) there may be air in the ABS module... when I got my 06 3.7L Liberty the left rear brake line somehow got wrapped around the front driveshaft and ripped the line out of the ABS module...
There was air in the whole system... The regular bleeding of the brake lines didn't help...To clear out the air bubbles in the module you need to exercise the motor and valves... The local dealer wanted more to do this than buying an Ancel AD-610 ABS & Airbag reset tool... This is an OBDII reader/scanner also...
I bought it on ebay for 109.48 US$... That did the job and also became part of my automotive "tools"...
It's well worth having as it reads ABS and Air Bag codes..
Dave

 

[Tog]

The sponginess does seem to go when it's cold so maybe the issue is a seized caliper.

2004 3.7 limited

 

[Tog]

issue found 1 severely shagged wheel bearing

2004 3.7 limited