Sinking Brake Pedal

[Irrenhaus]

Hi Everyone,

 

I have a 2012 Dodge Journey SXT with the 3.6L engine. The initial problem I was having is that during driving on random occasions the brake pedal will sink to the floor. On some occasions after hitting a bump or a pothole. I went ahead and replaced the brake pads and rotors also replaced the brake master cylinder and then bleed the whole system. But I still have a sinking brake pedal and now is all the time. It will get a bit hard when the car is off but it will sink and it feels smoosh when the car is on.

 

Any recommendations will be welcome.

 

Thanks.

[John/Horace]

Check connections on vacuum booster. Check valve or hose could have an issue. Scan for any brake codes in ecm.

 

 

[sppmaster]

Is there anyone here that suffered from sinking brake pedal and the video above helped him resolve the issue?

[John/Horace]

The caliper piston needs to make contact when pressure bleeding to properly push the air out. I have had a rear disc brake caliper not making contact with new pads and rotor on a Hyundai vehicle. It had the locking parking brake caliper pad set up like on Journey.

Cycling parking brake did not seem to help any.

 

After messing around I ended up adjusting piston for more contact and no gap. Air then pushed out with a gravity bleed, and pedal cycling. So this is correct helpful information for Journey rear calipers with air trapped in system.  Pedal height is also affected by pad wear, new pads keep it slightly higher.

Edited May 21, 2021 by John/Horace

[sppmaster]

7 hours ago, Locosiete said:

And JUST to confirm what order are you doing them in? Should always do in the order assuming you don't have a right hand drive vehicle. 

1st) rear passenger

2nd) rear driver 

3rd) front passenger 

4th) front driver

 

Thanks.

Are you sure about the order.

I've read in this NHTSA Safety Recall it is

NOTE: The following wheel sequence should be used when bleeding the brake
hydraulic system. The use of this wheel sequence will ensure adequate
removal of all trapped air from the brake hydraulic system.
 Left Rear Wheel
 Right Front Wheel
 Right Rear Wheel
 Left Front Wheel

Edited May 21, 2021 by sppmaster

[sppmaster]

4 hours ago, Locosiete said:

I've always been told start with the wheel furthest from the master cylinder and then work towards it. Doesn't mean i was ever told correctly though ???

Again that's assuming you have a left hand drive vehicle. And this was also starting on cars pre ABS.

Yes you've been told right... furthest first. And you are right... pre ABS era.

The Left Rear Wheel (in this case particularly) is furthest from the master cylinder. The master cylinder is on the drivers side then the brake line is going to the ABS/HCU block which is on the passenger side and then going to the left rear wheel which is furthest from ABS/HCU respectively from the Brake Master Cylinder .

Edited May 21, 2021 by sppmaster

[John/Horace]

Cross bleeding for air, section of clear vinyl 1/4” hose on bleeder screw to see the air bubbles.  Nickel copper alloy brake line, not old school steel. Flares easy, no tubing bender unless you are ver fussy. Lasts great in rust belt areas, most performance guys use it now.

Labor savings makes the extra $2 per foot cost negligible.  Good for classic cars. Even metric bubble flares on first try by non mechanics. 

[John/Horace]

The google....

 

The diagonal arrangement has been the default for several decades now. A diagonal split is safer in the event of the failure of one circuit: it leaves you with one front brake, whereas a F/R split could leave you with rear brakes only, and a vastly longer stopping distance.Jan. 21, 2017

[sppmaster]

I've published my new findings here.

The video published above still didn't help in my case but we found out interesting other things.

Edited May 27, 2021 by sppmaster