sppmaster Posted January 21, 2020 Report Share Posted January 21, 2020 (edited) As a continuation to my previous posts about the issues with the brakes now I publish a new video just to check if any of you have the same play in master cylinder and vacuum booster when you press the brake pedal. Please comment if your master cylinder moves when you press or pump the brake pedal. It has approx 5-10 mm play when pushed by hand too. The mechanic from the dealer service shop says all this play is normal. Maybe a new joke? Edited January 21, 2020 by sppmaster Quote Link to comment Share on other sites More sharing options...
Nelson Posted January 22, 2020 Author Report Share Posted January 22, 2020 On 1/21/2020 at 7:13 AM, sppmaster said: As a continuation to my previous posts about the issues with the brakes now I publish a new video just to check if any of you have the same play in master cylinder and vacuum booster when you press the brake pedal. Please comment if your master cylinder moves when you press or pump the brake pedal. It has approx 5-10 mm play when pushed by hand too. The mechanic from the dealer service shop says all this play is normal. Maybe a new joke? I’m pretty sure that movement of the master cylinder is normal, I noticed the same thing on the car I was working on. Just make sure the two nuts are tight that hold the master to the brake booster. The sinking brake pedal is not normal or safe in any way so inspect your rear calipers carefully, that’s most likely where the problem is. If your unsure just replace them both and bleed the lines again. That’s what fixed the problem for me so it’s worth a shot especially if the dealer is giving you the runaround. Quote Link to comment Share on other sites More sharing options...
sppmaster Posted January 23, 2020 Report Share Posted January 23, 2020 21 hours ago, Nelson said: I’m pretty sure that movement of the master cylinder is normal, I noticed the same thing on the car I was working on. Just make sure the two nuts are tight that hold the master to the brake booster. The sinking brake pedal is not normal or safe in any way so inspect your rear calipers carefully, that’s most likely where the problem is. If your unsure just replace them both and bleed the lines again. That’s what fixed the problem for me so it’s worth a shot especially if the dealer is giving you the runaround. What might be the issue with the rear calipers. What exactly was your problem. Quote Link to comment Share on other sites More sharing options...
2late4u Posted January 23, 2020 Report Share Posted January 23, 2020 1 hour ago, sppmaster said: What might be the issue with the rear calipers. What exactly was your problem. search for the problem under the forums Brake, Chassis & Suspension Quote Link to comment Share on other sites More sharing options...
Nelson Posted January 23, 2020 Author Report Share Posted January 23, 2020 6 hours ago, sppmaster said: What might be the issue with the rear calipers. What exactly was your problem. Did you read the first page of this thread? I explained every step of the problems the car had and how I fixed it. Long story short, one of the rear calipers was not working, the piston was not squeezing the brake pad against the rotor. I don’t know what caused it to fail or how it caused a low pedal but it was the problem and a new caliper fixed it. The car is still driving around today with a good firm brake pedal. 2late4u 1 Quote Link to comment Share on other sites More sharing options...
sppmaster Posted January 24, 2020 Report Share Posted January 24, 2020 3 hours ago, Nelson said: Did you read the first page of this thread? I explained every step of the problems the car had and how I fixed it. Long story short, one of the rear calipers was not working, the piston was not squeezing the brake pad against the rotor. I don’t know what caused it to fail or how it caused a low pedal but it was the problem and a new caliper fixed it. The car is still driving around today with a good firm brake pedal. Yes I'd red it but sorry just overlooked your other post. I've thought the stuck caliper would make the car pull to the side when braking. I've done a brake system test on brake stand all wheels stopped evenly with the needed force. Anyway thanks for your answer I'll have to check this. Quote Link to comment Share on other sites More sharing options...
sppmaster Posted January 30, 2020 Report Share Posted January 30, 2020 (edited) On 26.09.2019 г. at 11:50 PM, 2late4u said: if the caliper piston is not fully extending then it wont tighten onto the rotor....also look at the front of the caliper piston if there is groves like a plus then these are the ones you have to turn in i bought a cheap cube tool that has different nubs on it that fit into the groves and then use a ratchet to turn . here is piture of it about $7.at harbor fright or most part stores I have read on another forum that this cube tool is useless. It's here - https://forums.tdiclub.com/showthread.php?t=360099 Quote of it - I bled the rear calipers just to see if maybe that would solve the problem. Lo and behold, a giant air bubble came out of the driver's side rear caliper. No air was removed from the passenger side. I sealed everything back up, topped off the brake fluid, and normal brake pedal feel and action were restored. Failure analysis: Thinking back through the events when I replaced the rear pads, I remembered that the driver's side rear caliper was the first one I worked on. I had tried to use the universal cube tool to reset the pistons and I realized that I was turning the piston the wrong way. I ended up backing the piston out of the bore to the point where it became cocked. There must have been enough of an air gap to admit a large quantity of air into the cylinder, causing the loss of pedal firmness and authority. Lessons learned: Use the proper tools (i.e.: not the useless "cube" tool) for resetting the calipers. I've found a lot of cases on different forums where the brake pedal starts sinking and parking brake not working well after the rear pads replacement (as in my case). One of the best threads is here (first post) - https://dodgeforum.com/forum/dodge-caravan/335390-2010-caravan-rear-calipers.html The solution was to screw the pistons back out and that fixed the sinking pedal and made it firm again. I saw another user opinion here - https://www.fixya.com/cars/t21869850-brake_pedal_soft Quote - Dodge journey rear calipers will not always automatically adjust after compressing them all the way to change pads. One or both of the Pistons retracts all the way creating slack. If you're able to jiggle the brake pads or rotors the caliper piston needs to be turned counter-clockwise until there's no slack but hub is still allowed to turn. Edited January 30, 2020 by sppmaster 2late4u 1 Quote Link to comment Share on other sites More sharing options...
sppmaster Posted January 30, 2020 Report Share Posted January 30, 2020 I've found this too - https://www.northamericanmotoring.com/forums/stock-problems-issues/229045-another-spongy-brake-thread-after-replacing-pads-rotors.html Quote - Well, I now know why no one ever posts the resolution to this... because they're too embarrassed as to the resolution. It was the brake pads installed incorrectly. When I did the rears, I picked up two pads and they looked identical so I thought they were universal. Installed those 2, then looked at the other side, yep, identical. What I didn't realize was that I put two inner pads on one side, and two outer pads on the other side. Sooo... fixed the pads. Brakes work perfectly now! Yes, we all have dumb moments. Hopefully my admittance of stupidity will help some other poor fool out. Probably this is for the front ones. Summer Solstice, 2late4u and NavalLacrosse 1 1 1 Quote Link to comment Share on other sites More sharing options...
Summer Solstice Posted January 30, 2020 Report Share Posted January 30, 2020 Thank you for the input. I have yet to do brakes on a Journey. Hints like this are very helpful when the time comes. Quote Link to comment Share on other sites More sharing options...
2late4u Posted January 30, 2020 Report Share Posted January 30, 2020 Failure analysis: Thinking back through the events when I replaced the rear pads, I remembered that the driver's side rear caliper was the first one I worked on. I had tried to use the universal cube tool to reset the pistons and I realized that I was turning the piston the wrong way. I ended up backing the piston out of the bore to the point where it became cocked. There must have been enough of an air gap to admit a large quantity of air into the cylinder, causing the loss of pedal firmness and authority. Lessons learned: Use the proper tools (i.e.: not the useless "cube" tool) for resetting the calipers. so it was the mechanics fault NOT the useless tool that turned the piston the WRONG way, by the way i use that same useless cube when i work on my journey and other vehicle that it fits ,,,LOL it works correctly every time for me,you must have got a defective one i would assume NavalLacrosse 1 Quote Link to comment Share on other sites More sharing options...
NavalLacrosse Posted January 30, 2020 Report Share Posted January 30, 2020 These responses are great! Thanks, community, for such a detailed overview; when the weather warms up i'll 1st) adjusting the spacing to see if that fixes the soft pedal, then 2nd, bleed them totally, to solve the problem. I rent the proper tool for free from autozone, $60 deposit OhareFred 1 Quote Link to comment Share on other sites More sharing options...
Nelson Posted January 30, 2020 Author Report Share Posted January 30, 2020 Let us know how it goes. Quote Link to comment Share on other sites More sharing options...
sppmaster Posted May 27, 2021 Report Share Posted May 27, 2021 (edited) 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. Edited May 27, 2021 by sppmaster Quote Link to comment Share on other sites More sharing options...
sppmaster Posted February 1, 2023 Report Share Posted February 1, 2023 (edited) 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. Edited February 1, 2023 by sppmaster Quote Link to comment Share on other sites More sharing options...
sppmaster Posted February 1, 2023 Report Share Posted February 1, 2023 Some more pictures. Unfortunately I cannot upload the others here. Quote Link to comment Share on other sites More sharing options...
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