sppmaster

Thanks both for your answers. The whole brake system (all calipers) was completely revised. All calipers move normally and the rotors and pads are completely new. I had the same soft and low brake pedal with the smaller brakes too. Actually it was perfect (no soft and low) but the dealer made a brake fluid change and then the pedal became soft and low. I use the parking brake every time I park the car. I'll try to perform brake air bleeding wit the diagnostic software.

I've just done the big brakes upgrade on all four wheels of my car. Thanks again for the perfect guide. The only issue that remains on my car is the low and spongy brake pedal. It seems like there is no solution to it. I've tried at least 10 other cars with the same low and spongy brake pedal and I'm really puzzled how often it can be seen and even more puzzled that the owners don't care for it. Here is the result.

I regret that I see your post so late. I don't know if I can help you seeing all that you've done but maybe you can check my posts here on this thread. Starting from the first one and reading to the last posts. Maybe you can try to repeat my tests just in order to try to pinpoint to the core of the issue. I am really amazed by the complete incompetence of the dealer service shop mechanics.

Some more pictures. Unfortunately I cannot upload the others here.

Latest update as of February 2023. I've found out the reason for this situation. I've disassembled the whole braking system and I've used a software tool to monitor the pressure inside the brake system while I've performed thoroughly various tests on the braking system. I've used plugs to block all the brake lines one by one and I've found out that the main culprit for the low and spongy brake pedal was the front right brake apparatus. Once the front right brake line was blocked with a plug the brake pedal immediately returned to its perfect old behaviour and feeling (very firm and within its normal working range movement). I've performed air bleeding several times using the conventional method and additionally I've used the scan tool to perform ABS air bleeding. There wasn't any air inside the brake system and nothing changed. The only thing I couldn't do was to completely disassemble the brake apparatus because I didn't have a spare one and I needed a working car (not stationary one). I don't know what's wrong with that particular brake apparatus, but once I realized that the brake system functioned normally (no pressure loss, brake fluid leakage, etc) I stopped rushing into the eventual brake apparatus change or its complete disassembly. Of course the main question - What is wrong with that particular brake apparatus? - remains unrevealed yet. Has anyone here made an attempt to disassemble a brake apparatus itself.

Thanks for your work but can you please take pictures of the exact oversized holes and put them here. I'm not a native English speaker and just wonder where are those holes.

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.

After a long delay because of the notorious pandemic crisis I continue my battle with the sinking brake pedal. I saw this post 2 weeks ago and as my symptoms were absolutely the same I believed that the problem might be in the rear brakes. Unfortunately even this one didn't solve my sinking and spongy brake pedal of Fiat Freemont (identical to Dodge Journey). We spent half a day trying to figure out the reason for the sinking brake pedal. I've got it sinking after I've changed the rear brake pads at the official service shop of Fiat 2 years ago. Today after we checked all the brake apparatus and initially couldn't find anything obvious we decided to clamp all the brake hoses. Immediately the pedal became nice and firm again as it was before the break pads change. It stopped going to the floor. After that we removed the clamps one by one and found out that when only both rear brakes were clamped the pedal was still sinking to the floor and felt spongy. When both front brakes were clamped the pedal became firm again and didn't sink anymore. When only the left front brake is clamped the pedal is still sinking but more slowly. When only the right front brake is clamped the brake pedal is almost (maybe 90-95%) completely firm and cannot go completely down to the floor. With a long pry we tried to support the front brakes and we saw that there is a little lateral movement of the two front brake apparatus when pumping the brakes. There is no visible hub play so I assume the bearings are OK. We saw that the slide pins move laterally maybe 2-3 millimeters and the brake clamps bend a little when someone pump the brake pedal. We couldn't see similar play and bending of the rear brake apparatus. Next maybe we'll have to change the slide pins to see what would happen then. It is probably obvious that we performed air bleeding 2 more times.

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 .

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

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

You are really great. Maybe in this case it'll be easier for you to take a note of the date of your posts and search your backup for pictures taken around that dates. Edit: I've got 2 pictures from webarchive - there are dates on them.

Maybe the Author of this thread can recover the pictures.

If anyone is able to pull it from here Internet archive here www.archive.org I've tried but I can see only a few pics. Can anyone try to pull the archived page. Maybe we still have a chance.

Unfortunately I cannot see any pictures on the first three posts. They just don't load. Did anyone have an archive of these really useful posts (first, second and third one) to save this excellent job.