Spodie Posted February 7, 2006 Share Posted February 7, 2006 I've got a 96 Legacy Outback. Put new pads on the front wheels today. When I did, I disconnected the lines at the caliper instead of opening the bleed nut to get the pistons back. (it was much easier to get the pistons back with the entire caliper removed and line disconnected, plus got to purge some dirty fluid.) Reassembled everything, but the sun went down before I could bleed them. Pedal is currently uselessly hitting the floor. I've replaced pads on a car or two in the past,but never lost any fluid in the process, so I've never bled brakes. I know it isn't a big deal, but after reading a couple of posts, I'm starting to get nervous. Couple of questions. 1. Do I have to bleed the REAR brakes even though they were untouched? 2. Should the fluid resevoir cap be ON or OFF? I understand that the fluid should not be allowed to empty. 3. I believe that I should bleed each bleed nut starting at the farthest from the master cylinder, but how do I know when I'm done? The goal is to eliminate air bubbles, is it very apparent when only fluid is coming from the bleed nut? Will the bubbles be forced to the brake first, or could I be leaving one in there that happens to be pushing out a steady stream of fluid? 4. I am assuming that the pedal will keep hitting the floor until all brakes are bled. At that point, the last bleed nut should be closed. Then it should take a couple of pumps to get stiffness back into the pedal and I'm good to go. Am I correct? Is there any other adjustments I need to make? 5. Is there anything I have forgotten or any rookie mistakes that will sink me? I'd appreciate ANY input, I'm hitting this thing tomorrow one way or the other. Thanks! Quote Link to comment Share on other sites More sharing options...
nipper Posted February 7, 2006 Share Posted February 7, 2006 1-The car has a split diagonal brake system. left front/right rear and right front/left rear are on the same circuits. Technically you have touched the rear brakes. 2-The cap should could be either. With all metal master cylinders you would keep the cap off. With plastic resivours you can put it back on. The resivour should never be allowed to empty, and use new brake fluid. do not reuse the fluid that has been bled out. 3-You are done when there is a steady stream of fluid out the bleed nut. This may take a while so dont be surprised. 4-Pedal whould have pressure as soon as you are done bleeding. May take one more pump to fully seat pads and everything, but no more. 5-the bleed valve. close it after every brake pedal application so you do not suck air back into the system. Have your pedal pumper keep thier foot in the brake pedal until the valve is closed. Do not reuse the brake fluid as it is airated. Brake fluid is cheap enough. Do not leave the cap off the brake fluid between topping off the resivoir. brake fluid and humidity dont mix. i'm sure the others may have something to say Quote Link to comment Share on other sites More sharing options...
Setright Posted February 7, 2006 Share Posted February 7, 2006 Disconnected lines would always lead me to a bleed. Yes, you need to bleed all four wheels to ensure similar fluid in all the lines and therefore even brake distribution. With the engine off you get a more direct feel since the vacuum assistance is gone after a few applications. You can be fairly certain that the air is gone once the pedal feels firm. Flushing requires a liter of fluid. Quote Link to comment Share on other sites More sharing options...
Spodie Posted February 7, 2006 Author Share Posted February 7, 2006 So I should leave the engine off.... PR,DR,PF,DF still the correct order with the crosswise brake system? Quote Link to comment Share on other sites More sharing options...
Spodie Posted February 7, 2006 Author Share Posted February 7, 2006 One more thing, I had the parking brake on for the front disc change, to back up the chocked tires to prevent rolling off the jacks. Should I have the park brake on or off to bleed the rear brakes? does the park brake use the rear brakes the same as the brake pedal or is it a seperate system? Do I have to bleed the Park Brake? I assume it is a mechanical cable, not hydraulic, but not sure how it affects things if is using the caliper. I'm inclined to leave it the way it is for continuity. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted February 7, 2006 Share Posted February 7, 2006 parking brake is mechanical and must be on the rears if you didn't encounter any problems with the front brake pads. with it on the brakes are not removable (without a torch at least!!). so it must be on the rear and you can leave it on if you'd like. i don't recommend this, but i have broken front lines before and just bled that line. not ideal but it can be done. but not in your case since it's been drained and sitting over night. if it was small amount of fluid loss and you could do it right away, you might be able to get away with it but it's not an option for you right now. Quote Link to comment Share on other sites More sharing options...
tcspeer Posted February 7, 2006 Share Posted February 7, 2006 You only need to bleed all four when you disconnect at the master cyclinder, If you undo only one line that is all you need to bleed. Next time just push the piston back in with a C- clamp and dont undo the line. Quote Link to comment Share on other sites More sharing options...
nipper Posted February 8, 2006 Share Posted February 8, 2006 Its always a smart thing to do all 4, especially if you are replacing a lot of fluid. For the extra 10 minutes its not a bad thing to do. nipper Quote Link to comment Share on other sites More sharing options...
Spodie Posted February 8, 2006 Author Share Posted February 8, 2006 Thanks all, Bled all four and works like a charm. Nice to keep a few hundred bucks in my pocket... I'll definately do the C-clamp next time. Quote Link to comment Share on other sites More sharing options...
tcspeer Posted February 8, 2006 Share Posted February 8, 2006 Why? do you patch all four tires when you have a flat on one? Its always a smart thing to do all 4, especially if you are replacing a lot of fluid. For the extra 10 minutes its not a bad thing to do. nipper Quote Link to comment Share on other sites More sharing options...
nipper Posted February 8, 2006 Share Posted February 8, 2006 do you just replace one shock on an axle? i can play this game too. It amazes me how people wont take an extra 30 minutesor less to bleed all four wheels . Every shop i worked in, when i was Automotive school, we were taught and trained to bleed all four wheels. Saftey isn't worth taking shortcuts. when was the last time you saw on a bill "replaced caliper bled one wheel" nipper Quote Link to comment Share on other sites More sharing options...
idosubaru Posted February 8, 2006 Share Posted February 8, 2006 Why? do you patch all four tires when you have a flat on one? that's a terrible analogy. one tire isn't related to the others, entirely independent and stand alone items. the brakes system (if you'd read through the post) has shared lines between front and back. air introduced at one tire can get into lines affecting other calipers. it is very common practice to bleed the entire brake system, most people do. i always do, (with one exception mentioned earlier, that i do not recommend if you don't know exactly what you're doing and it's your car and you know how to rectify it if there's any *play* later). Quote Link to comment Share on other sites More sharing options...
idosubaru Posted February 8, 2006 Share Posted February 8, 2006 do you just replace one shock on an axle? i can play this game too. ha ha, that's funny. Quote Link to comment Share on other sites More sharing options...
nipper Posted February 8, 2006 Share Posted February 8, 2006 ha ha, that's funny. The sad thing is is that i know somone who does it, then wonders why his tires wear odd. From a common resevior (one for one line, one for the other) you have ONE brake line that goes into a "T" fitting. from there the lines have their other valves (proportining, brake failure switch).. assuming 4 wheel discs. Now if each wheel had its own brake line then the bleed one wheel thing would be valid. Since the "T" now makes front and rear joined, the front and rea have to be bled. Since he opened up both front lines, all four wheels have to be bled. Even if i just opened one line, i would still do all 4 as a maintanence item. This is not just something for the mechanic to make more money, as he charges the same for one as for four (he would never charge for one since it just is not done that way). nipper Quote Link to comment Share on other sites More sharing options...
tcspeer Posted February 8, 2006 Share Posted February 8, 2006 Sounds like most of you have done more talking about brakes then working on them. From Haynes Automotive Brake Manual page 9-45 (It will probably be necessary to bleed the system at all four brakes if air has entered the system due to low fluild level, or if the brake lines have been disconnected at the master cyclinder. If a brakeline was disconnected only at a wheel, then only that caliper or wheel cylinder must be bled.) I like most of you used to bleed all four cyclinders until someone taught me the correct way. If you want to crawl around and do all four wheels it is not going to bother me, I was just trying to help you out. Next time you have only one off to repair the caliper or wheel cyclinder give it a try and then decide if you want to do the other three. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted February 8, 2006 Share Posted February 8, 2006 Sounds like most of you have done more talking about brakes then working on them. hey play nice! i've lost track of brake jobs.....3 dozen would be a wild guess. i don't disagree, i even mentioned doing one myself. this is partially a discussion of semantics - nipper is speaking to a broad audience (average person asking questions doesn't know much about cars) and you're speaking to knowledgeable folk (yes you can get away with less work if you know what you are doing and what to look for). for the average person posting and asking questions it's probably not a bad idea to do them all until/unless they feel very competent diagnosing cars and brake systems. those giving advice here often know much more about cars than those taking advice (most users!) so being on the conservative side is in the majority's best interest. i recall when i first started i just did what people told me and didn't really understand how things worked. the haynes manual is a nice tool, but is wrong sometimes and there is documentation saying bleed them all...not all literature is perfect. haynes manuals are considered far inferior to the FSM and for good reason. Quote Link to comment Share on other sites More sharing options...
tcspeer Posted February 8, 2006 Share Posted February 8, 2006 Sorry! I thought yall was ganging up on me. Three dozen is a good start. hey play nice! i've lost track of brake jobs.....3 dozen would be a wild guess. i don't disagree, i even mentioned doing one myself. this is partially a discussion of semantics - nipper is speaking to a broad audience (average person asking questions doesn't know much about cars) and you're speaking to knowledgeable folk (yes you can get away with less work if you know what you are doing and what to look for). for the average person posting and asking questions it's probably not a bad idea to do them all until/unless they feel very competent diagnosing cars and brake systems. those giving advice here often know much more about cars than those taking advice (most users!) so being on the conservative side is in the majority's best interest. i recall when i first started i just did what people told me and didn't really understand how things worked. the haynes manual is a nice tool, but is wrong sometimes and there is documentation saying bleed them all...not all literature is perfect. haynes manuals are considered far inferior to the FSM and for good reason. Quote Link to comment Share on other sites More sharing options...
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