stevecd Posted February 12, 2006 Share Posted February 12, 2006 Well this is the first time I’m posting about a problem but anyways, I have a 93 Subaru legacy ls and I have a intermit problem with the brakes that i feel need to be address asap. What happens is a complete lost of brakes where I have to pump a few times to get enough pressure to stop. What I believe is happening besides the magic gnomes not wanting to work is the parking brake is getting stuck, which then over heats the disk along with the caliper so that the brake fluid doesn't work anymore and so I lose all the pressure I need for braking. So far it has only happened 2 times. Both times I noticed the rear wheel once left and once right very hot in temperature. Anyways wondering if anyone has any suggestions and no I didn't leave the parking brake on. ~Steven Link to comment Share on other sites More sharing options...
tunered Posted February 12, 2006 Share Posted February 12, 2006 i dont think thats it,your parking brake does not use the same pads as the rear brakes,even tho heat might transfer that far but i dought it.i would think you would notice dragging brakes,will it coast on a slight grade?im taking bets that there is air in the system. even if it was what you think,i dont think it would effect the front brakes so much as having none.i think a good bleeding would be my first task plus look for leaks around the wheels and under car. Link to comment Share on other sites More sharing options...
stevecd Posted February 12, 2006 Author Share Posted February 12, 2006 Well I understand the pads are different for the parking brake vs. normal brakes but the heat I noticed from both times this has happen was so hot I could not even touch the wheel rim . I how ever didn't notice the brakes dragging but I do a lot of freeway driving with cruse control set. What does happen I believe before it fails is my brakes get abnormally responsive like as if the parking brake was on. I now check each time after I drive if the rear wheels are hot or not and usually half the time one or the other is considerably hotter then the other wheels which tells me it was going to happen again. Anyways I will get to work on the bleeding asap. ~Steven Link to comment Share on other sites More sharing options...
tunered Posted February 12, 2006 Share Posted February 12, 2006 it seems odd that the rear brakes seem to take turns at getting hot at different times,i think i would also jack up the rear and have somebody apply the brakes and see if they are releasing.i cant imanagine not having any brakes when this happens,99 times out of 100 when you have to pump the pedal to get brakes its because of air in the lines,having said that when pressure builds from heat like you are saying that you think it is usally makes more brakes,not less. sometimes it feels like brake fade at its worst but usually you have pedal. kinda stumped here. let us know how it goes. Link to comment Share on other sites More sharing options...
dxrflyboy Posted February 12, 2006 Share Posted February 12, 2006 It sounds like an internal leak in the master cylinder. Link to comment Share on other sites More sharing options...
Strakes Posted February 12, 2006 Share Posted February 12, 2006 The master cylinder probably is the offending party. Link to comment Share on other sites More sharing options...
tcspeer Posted February 12, 2006 Share Posted February 12, 2006 I agree with the master cyclinder being the problem. Link to comment Share on other sites More sharing options...
stevecd Posted February 12, 2006 Author Share Posted February 12, 2006 eek master cylinder is there maybe a *easy* way to test or is it just a replace and see if the problem goes away solution. btw if its the master cylinder wouldn't it happen every time I drove not just once in awhile. Again thanks for the input. ~Stevecd Link to comment Share on other sites More sharing options...
dxrflyboy Posted February 12, 2006 Share Posted February 12, 2006 If the pedal goes to the floor, whether constantly or intermittently, there are no external leaks, and the system hasn't been opened recently, process of elimination leaves the MC as the only remaining culprit. If you still have doubts, remove the master and take it apart. It's probably full of black sludge. Link to comment Share on other sites More sharing options...
stevecd Posted February 12, 2006 Author Share Posted February 12, 2006 yea I agree the master cylinder is probably to blame but would it also cause either of the rear brakes to get really hot or do I have two problems one causing the other. I don't want to replace the MC and then it break again because of something in the rear brakes not working. ~Steven Link to comment Share on other sites More sharing options...
OB99W Posted February 12, 2006 Share Posted February 12, 2006 yea I agree the master cylinder is probably to blame but would it also cause either of the rear brakes to get really hot or do I have two problems one causing the other. I don't want to replace the MC and then it break again because of something in the rear brakes not working.~Steven It seems that you've got master cylinder trouble, probably related to or compounded by contaminated brake fluid. Modern brake systems use dual-diagonal configuration, so problems in one diagonal circuit are usually isolated from the other one, which could explain why a different rear wheel at certain times seems to be affected. Check valves and compensating ports in the master cylinder determine how hydraulic pressure is applied and released, but contaminants in the fluid can cause valves to get stuck or ports to get blocked. That can result in reduction of pressure to wheel cylinders, or even line pressure not being released when you remove your foot from the brake pedal (causing what might seem like intermittently stuck calipers and "really hot" brakes). Contaminants can also cause excessive wear. The master cylinder should likely be replaced, and the rest of the brake system thoroughly flushed with fresh fluid. There may still be things sticking at the wheels even after that, but it's a starting point. Link to comment Share on other sites More sharing options...
Olnick Posted February 12, 2006 Share Posted February 12, 2006 I agree with the MC diagnosis and the probability of contaminated brake fluid. But you might also want to pull the rear calipers (or all of them for that matter) and make sure the guide pins/bushings are clean, greased and smooth acting. Good luck. Link to comment Share on other sites More sharing options...
stevecd Posted February 12, 2006 Author Share Posted February 12, 2006 yea i did check the calipers in the rear and the drum in the rear and it seems like they are doing what they are suppose to smoothly. I'm guessing its the MC but i just don't want to buy a new one and having it not fix the problem since they are expensive and not a fun job to replace since i would have to re bleed the brakes but since i can't find any leaks i can't point the finger at anything else. thanks for all the info and help i will get to work on it probably mid week and let you guys know how it goes. ~Stevecd Link to comment Share on other sites More sharing options...
stevecd Posted February 19, 2006 Author Share Posted February 19, 2006 Replaced the master cylinder today however I haven’t drove much today but already it seems like my brakes are more responsive and hopefully I won't get that problem again. Anyways just want to thank everyone for their help. Below is the picture of the old MC. Link to comment Share on other sites More sharing options...
tcspeer Posted February 19, 2006 Share Posted February 19, 2006 I think your rear brakes always got hot and you did not notice until you went looking for the problem. After a few stops in my car they are really hot you find this out by having to change a flat after using the brakes. yea I agree the master cylinder is probably to blame but would it also cause either of the rear brakes to get really hot or do I have two problems one causing the other. I don't want to replace the MC and then it break again because of something in the rear brakes not working.~Steven Link to comment Share on other sites More sharing options...
stevecd Posted February 19, 2006 Author Share Posted February 19, 2006 I think your rear brakes always got hot and you did not notice until you went looking for the problem. After a few stops in my car they are really hot you find this out by having to change a flat after using the brakes. well my whole brake system failed a few times and it wasn't always that the rear brakes get hot only once in awhile. thats why the replaced the MC YMMV. ~stevecd Link to comment Share on other sites More sharing options...
stevecd Posted February 24, 2006 Author Share Posted February 24, 2006 guys bad news the problem i think is coming back, so far the brakes haven't failed but the pass. side wheel was temp. stuck for about 2 miles which made the wheel get very hot . so wondering if there is anything between the rear brakes and the master cylinder that i could check. thanks in advance for the help. Stevecd Link to comment Share on other sites More sharing options...
nipper Posted February 24, 2006 Share Posted February 24, 2006 guys bad news the problem i think is coming back, so far the brakes haven't failed but the pass. side wheel was temp. stuck for about 2 miles which made the wheel get very hot . so wondering if there is anything between the rear brakes and the master cylinder that i could check. thanks in advance for the help.Stevecd Ok your going to test the power brake booster. i was going to post this farther upbut saw you already replaced the master cylinder. The two can mimic each other, so you usually rule out the booster first. With the car off pump the brakes 10-15 times to exhause all the vacume. Put your foot on the brake pedal, then start the car. The pedal should go towards the floor. Repeat this test a few times. Inspect the rear calipers, you can have a stuck caliper causing the heating by draging the pads. Also the brakes are not split front rear. They are dignol as they have been in most cars for the last 15 years. Left fr/right r and right frt/left r are connected to each other. Another thing to look at is to replace the flex brakes lines. They can fail internally and you would never know it. nipper Link to comment Share on other sites More sharing options...
seattlelegacy Posted February 24, 2006 Share Posted February 24, 2006 Brakes getting stuck is more than likely a caliper problem. Otherwise, when you changed your MC, did you completely flush the system, or did you just bleed a little off? I ask, because if you had sludgy BF in the MC, then its likely sludgy all over, which could also cause the brakes to stick. Your master cylinder is creating a lot of pressure, which is transferred to each wheel. If there is gunk in the lines, then when the pressure is applied and subsequently released, the gunk can hold pressure on the line to any given wheel. A cheaper option is to get an angle grinder and cut out your floorboards. I saw this on another board: Link to comment Share on other sites More sharing options...
stevecd Posted February 24, 2006 Author Share Posted February 24, 2006 I’m guessing it probably something in the lines so could I just take the lines out and check them by flowing fluid in or is it something like the lines collapsing? Hopefully this thing gets fixed. ~Stevecd Link to comment Share on other sites More sharing options...
seattlelegacy Posted February 24, 2006 Share Posted February 24, 2006 If you're going to remove the lines, you may as well replace them if you plan on having the car for more than a month. They're cheap. Also, I'm sure you already know, but make sure to bleed the hell out of them. Link to comment Share on other sites More sharing options...
nipper Posted February 24, 2006 Share Posted February 24, 2006 I’m guessing it probably something in the lines so could I just take the lines out and check them by flowing fluid in or is it something like the lines collapsing? Hopefully this thing gets fixed.~Stevecd Just replace them, as you cant re-create a brake system in your garage to reproduce the conditions the hoses are under. nipper Link to comment Share on other sites More sharing options...
stevecd Posted February 24, 2006 Author Share Posted February 24, 2006 ok off to the auto store thanks for the help guys i will let you know when i get done. ~Stevecd Link to comment Share on other sites More sharing options...
stevecd Posted March 1, 2006 Author Share Posted March 1, 2006 well after hearing that brake hoses cost about $50 each I decided to wait on it and check if you guys can think of anything else. Today however it happened again when i was going home from school so i thought it would be a good time to see what it looks like while its failing and check around, well i jacked up the car while the wheel was stuck and since it was so hot i decided to wait a little, while waiting for it i noticed each time i checked it would get a little more unstuck with the temp. going down until it was cold enough to take it off it seemed as though it was normal again "unstuck". so i though maybe their was air and i spent the last hour or so flowing brake fluid though not finding any bubbles. So i was wondering if this confirmed the brake hoses are bad or is this something else and also if anyone know where i could get brake hoses cheaper then $50. ~Stevecd Link to comment Share on other sites More sharing options...
nipper Posted March 1, 2006 Share Posted March 1, 2006 sigh ok you have a bad caliper. As the caliper get hot metal expands. As the metal expands things are binding. The slider on your caliper is hanging up due to rust crud or whatever. The calpier slider can be cleaned and lubricated. i recomend all four be done. The brake line price is very high, i bet you went to the dealer and not an autoparts store. Also ask yourself, is your life (or somone elses) worth the cost of new brake lines? Others here may have a better source for brake lines. nipper Link to comment Share on other sites More sharing options...
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