Jsvob03 Posted July 12, 2009 Report Share Posted July 12, 2009 It was either here, or off topic, but i figure the info is good for either bikes or cars, to a point.Here's the deal. my car (2004 Chevy classic, its an 03 body malibu, with the 04 engine/trans.) Has had some mushy brakes for a while. I am comparing the brake pedal to the one in my GF's car (same car, ghey huh?). her's has the normal play at the top, and then nice n firm (the pedal guys..). mine...is weak. it feels like there is air in the lines. Here's what i've done, in order.-Replaced the Shoes/Drums, due to the shoes being worn out. same for the drums. While i was at it, i figured i could attack the noisy front calipers. -replaced two front calipers, cleaned & greased slides/pins. at that point, i still had a mushy pedal. I went thru and bled PER GM specs (RR, LF, LR, RF). No joy.-I then went thru and said, its gotta be the master cylinder. Replaced, bench bled, and rebled the entire system, showing no air anywhere. STILL mushy.-One of the tech's i work with noticed when we bled the LF, less fluid came out as compared to the other corners. So i replaced the flex hose. I have more fluid now, BUT still a mushy pedal. ARGH. I came home today, re-bench bled the master, re-bled the bejebus out of the entire system. same mushy ass pedal. At this point, im pissed at the car. I've been working on/around cars for 6 years now. Definately not a newbie. not ASE, YET, but just need to take the tests. So im not car retarded, and to this point have done everything the proper way. Can anyone shed some light as to what the hell is going on here?! I suspect something is up in the combination valve, but thats only cause its one of the few things remaining, lol. Quote Link to comment Share on other sites More sharing options...
Likwid Posted July 12, 2009 Report Share Posted July 12, 2009 I get the feeling you say things then smile and say "no pun intended" when you really did intend it....don't deny it! Quote Link to comment Share on other sites More sharing options...
R1Limited Posted July 12, 2009 Report Share Posted July 12, 2009 Could be your brake booster- the power assist just isn't working correctly. Seems like you have worked your way back from the wheel and haven't found anything. Is your master cylinder clean and working properly? Quote Link to comment Share on other sites More sharing options...
MidgetTodd Posted July 12, 2009 Report Share Posted July 12, 2009 When I do a whole system like that I open all bleeders and let the whole thing gravity bleed for several refills of the master then close and bleed a wheel at a time Ive had much better results that way plus I vacume bleed instead of the pedal method , and Ive got a brand new bad master cylinder more than once Quote Link to comment Share on other sites More sharing options...
Jsvob03 Posted July 12, 2009 Author Report Share Posted July 12, 2009 I get the feeling you say things then smile and say "no pun intended" when you really did intend it....don't deny it!damn. he's onto me...I'll try the all four bleeders open. if the booster was bad, it would cause a rock hard pedal. Lastly, Im gonna take the master back tomorrow, and just tell them it wont work, and see what happens when i put on another one. Quote Link to comment Share on other sites More sharing options...
MidgetTodd Posted July 12, 2009 Report Share Posted July 12, 2009 thatd be what id do , I'd try the gravity bleed before taking the master back as its pretty easy to do Quote Link to comment Share on other sites More sharing options...
hue jass Posted July 12, 2009 Report Share Posted July 12, 2009 You've still got air in the system. When you bleed using the pedal, you really can't get all of it thoroughly. All it takes is a small bubble up in one of the lines and there's your mushy pedal.Motive Products makes a great bleeder that will last you the rest of your life. I have one and use it on both of my cars. Whenever I do something that could put air in the system, I just use this thing and flush the whole system. CLICK HERE Quote Link to comment Share on other sites More sharing options...
Jsvob03 Posted July 12, 2009 Author Report Share Posted July 12, 2009 i've actually considered buying one, just didnt know where to get one. i'll take a look around the area, and if not, maybe order. thanks ,. Quote Link to comment Share on other sites More sharing options...
gruss Posted July 12, 2009 Report Share Posted July 12, 2009 ...in my GF's car (same car, ghey huh?). Yes Quote Link to comment Share on other sites More sharing options...
hue jass Posted July 12, 2009 Report Share Posted July 12, 2009 I'm sure they sell them at Jeg's. In fact, here ya go. CLICK HERE Quote Link to comment Share on other sites More sharing options...
chevysoldier Posted July 12, 2009 Report Share Posted July 12, 2009 Have you flushed ALL the old brake fluid out? Brake fluid absorbs moisture. If the fluid is dark, its contaminated and that could be why your pedal is mushy. If you havent done this yet, try it first. GL Quote Link to comment Share on other sites More sharing options...
Jsvob03 Posted July 12, 2009 Author Report Share Posted July 12, 2009 Have you flushed ALL the old brake fluid out? Brake fluid absorbs moisture. If the fluid is dark, its contaminated and that could be why your pedal is mushy. If you havent done this yet, try it first. GLoh yeah. definately has crystal clear fluid throughout. Quote Link to comment Share on other sites More sharing options...
chevysoldier Posted July 12, 2009 Report Share Posted July 12, 2009 (edited) After thinking for a while...Brakes shoes need adjusted. Adjust them until there is a little bit of drag when you spin the wheel by hand. The shoes are having to come out farther that they should.Maybe?Hopefully? Edited July 12, 2009 by chevysoldier Quote Link to comment Share on other sites More sharing options...
jporter12 Posted July 12, 2009 Report Share Posted July 12, 2009 After thinking for a while...Brakes shoes need adjusted. Adjust them until there is a little bit of drag when you spin the wheel by hand. The shoes are having to come out father that they should.Maybe?Hopefully?Good call! That's exactly what I would be checking! I have had this happen before, but usually on trucks. Does the car have ABS? If so, I think it's the Delco VI system, and you need to park the ABS motors. I've only had to do this on one or two of the MANY that I've replaced hydraulic brake components, but it could be what's going on! You have to use a scan tool to do this. Quote Link to comment Share on other sites More sharing options...
hue jass Posted July 12, 2009 Report Share Posted July 12, 2009 Yea, soldier, good call. I only figured from what he said his experience was that the rears were properly adjusted.Make sure the self-adjusters are set up and lubed. They have to work perfectly to maintain a good pedal. Quote Link to comment Share on other sites More sharing options...
chevysoldier Posted July 12, 2009 Report Share Posted July 12, 2009 Yea, soldier, good call. I only figured from what he said his experience was that the rears were properly adjusted.Make sure the self-adjusters are set up and lubed. They have to work perfectly to maintain a good pedal.He only said he replaced them. They may not be adjusted, I don't know tho. I have replaced shoes before and had to go back and readjust them. Jporter makes a good point to. Borrow a scan tool from autozone and check the codes.Drum brakes in general suck anyways. lol Quote Link to comment Share on other sites More sharing options...
hue jass Posted July 12, 2009 Report Share Posted July 12, 2009 Drum brakes in general suck anyways. lol+1 Quote Link to comment Share on other sites More sharing options...
chevysoldier Posted July 12, 2009 Report Share Posted July 12, 2009 +1 I was doing drums on on a car the other day and had not one, but 2 springs slip and bust me in the face. It was a shitty day to begin with anyways...I thought about telling them they dont need rear brakes Quote Link to comment Share on other sites More sharing options...
chevysoldier Posted July 12, 2009 Report Share Posted July 12, 2009 deleted Quote Link to comment Share on other sites More sharing options...
Jsvob03 Posted July 15, 2009 Author Report Share Posted July 15, 2009 to this point, it looks like the NEW master cylinder is bad. for somereason i keep getting air in the lines. Im gonna replace it (warranty), and take it from there.as far as the adjusters, abs.-No abs. Solves that. -adjusters are nice and lubed. If i have the rear off the ground i can spin either rear wheel, and they turn ~ 3 times and stop smoothly. no issues there. FYI, my car has one of those horseshoe springs GM loves. hell. i love it. i have the specialty tool, and changing shoes LITERALLY takes 5 minutes perside. thats removed, lubed all parts, reassembled. also, the ebrake actuator thing doesnt even need to come off the ebrake cable. talk about a nice setup..but yea, drum brakes = fail. Theres a disc conversion, but i realized its ONLY a malibu, so theres no need to put any more $$$ into it than is required. back on topic. thanks for all the suggestions guys/gals. greatly appreciate the input, and will let you know wht happens after the MC is changed. Quote Link to comment Share on other sites More sharing options...
chevysoldier Posted July 15, 2009 Report Share Posted July 15, 2009 GL, Let us know how it goes. Quote Link to comment Share on other sites More sharing options...
Jsvob03 Posted July 21, 2009 Author Report Share Posted July 21, 2009 (edited) ok..its fixed!! there were a few problems here, 2 actually.1.) The new set of calipers i put on were in fact bad, specifically it was the RF, not building/holding pressure. I dont understand how, but it was pulling in Air, not leaking fluid?! I replaced both calipers under warranty, and the pedal got better, but not where i wanted it, and not where it should be. so, 2.) I replaced the master cylinder(again), and bench bled, completely bled the system. after that, i had a nice pedal. But, i then noticed that the rear brakes were letting out quite a bit of heat, especially for drums. i spun the wheel in the air, and noticed that at a particular point the wheel was a bit harder to spin..which told me it was an out of round drum. So this past monday, i turned both drums, and re-adjusted the rear brakes. VERY, VERY solid pedal now, and this car stops amazingly well. The heat was coming from the shoes only making partial contact, and getting too hot in certain spots (evident by looking at the shoes).so yeah, PROBLEM SOLVED. thank you everyone for your input. Edited July 21, 2009 by Jsvob03 Typo. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.