HICKL Posted August 10, 2006 Share Posted August 10, 2006 I know about most of the upgrades, but I think something is wrong with my brake system. My rear brakes seem to be doing most of the work, I have a gravel driveway and can slam on the brakes in loose gravel and the rears will slide a long way and the fronts will barely lock. Entire system is stock but all seemingly in good working order. Have been driving the car for 4 years and has always been this way. Where should I start, master cylinder, proportioning valve? I wouldn't think it was the proportioning valve because both sides equally suck! I can't even do a good burnout because even with tires smoking, can't hold it still! thanks Jeff Quote Link to comment Share on other sites More sharing options...
MONGO510 Posted August 10, 2006 Share Posted August 10, 2006 Almost sounds like your front calipers are frozen or completely inoperative. Have you checked them? Quote Link to comment Share on other sites More sharing options...
deja Posted August 10, 2006 Share Posted August 10, 2006 Entire system is stock but all seemingly in good working order. Jeff Doesn't sound like its in good working order at all. How old is the brake fluid? With that 350 running headers is quite possible you have "cooked" the fluid from the header heat. Make sure the brake lines have been moved away from the headers. That happened to my clutch fluid in my V8 280Z. Then check the master cylinder, proportioning valve and then the front calipers. Rear wheels locking up first is very dangerous situation since you would have no control of the car in a panic stop. Quote Link to comment Share on other sites More sharing options...
HICKL Posted August 10, 2006 Author Share Posted August 10, 2006 Front callipers aren't frozen, they function just not very good. Deja, I guess what I should have said is all systems are "functioning" I flushed the entire system when I put the car on the road about 3 years ago and it has always been this way, even prior to the SBC install. Is there a scientific way to check the master? I know it squirts out of both ports but not sure if the front is week. Same question for the proportioning valve? I figure the problem is with one of those items but am hoping to prove without just dumping money on swapping parts. Thanks Again Jeff Quote Link to comment Share on other sites More sharing options...
johnc Posted August 10, 2006 Share Posted August 10, 2006 I wouldn't use a gravel road as a test for brake balance. Take it out on a nice, straight, traffic free road with wide shoulders and slam the brakes on a 30 mph. Get ready to catch it if the rear steps out. Quote Link to comment Share on other sites More sharing options...
Twoeightnine Posted August 10, 2006 Share Posted August 10, 2006 Food for thought.... A proportioning valve that splits the pressure ratio between the front and rear will most likely "mask" the root cause. If it is stock as you say then something is dead wrong. If you have replaced the front pads check them. If not replace them. If you feel confident that it's not the pads, and both sides of the front are weak, you have no choice but to suspect the master cyl. Its the only place that a stock sys splits front/rear duty. Think about it, both front calipers equally malfuctioning? Prob not. The cyl that operates both front calipers being bad, yep. Quote Link to comment Share on other sites More sharing options...
HICKL Posted August 10, 2006 Author Share Posted August 10, 2006 The gravel road was just to make a point, have been there done that on the street too many times. That's how I first realized I had a problem. Quote Link to comment Share on other sites More sharing options...
HICKL Posted August 10, 2006 Author Share Posted August 10, 2006 2eightynine, that's what I'm thinking. I don't understand enough about the proportioning valve to know how it would effect me. Is it splitting the pressure between the front and back or just the balance between the 2 fronts? Quote Link to comment Share on other sites More sharing options...
Twoeightnine Posted August 10, 2006 Share Posted August 10, 2006 Yep. If your car does the ass slide with no front bite. And does not walk off to the side violently. Your problem rest within the master cly. If you are willing to rebuild it, you can get away with a hone and O-ring deal. Brakes are important, new is good. Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted August 10, 2006 Share Posted August 10, 2006 If you have replaced the front pads check them. If not replace them. Double emphasis of this point. Can't imagine how an MC could be operating at 50% effectiveness for 4 years. Those pigs either work or they don't. Do a search for good street pad, put them on, replace the rotors and bed the pads. Get some stainless steel brake lines while you are at it. See what that does. There was a thread just the other week where someone fixed their brake effectieness with better pads. Quote Link to comment Share on other sites More sharing options...
spotfitz Posted August 10, 2006 Share Posted August 10, 2006 It sounds like glazed pads. Take them out and scuff them up with some 80 grit and replace. Bleed the system and bed the pads to see what it does. If it is the pads this is an easy test. Quote Link to comment Share on other sites More sharing options...
HICKL Posted August 12, 2006 Author Share Posted August 12, 2006 I bought some good pads yesterday, nothing special, just the best that that parts store had, skimmed my rotors and flushed all the brake fluid out and it seems to be better. Thanks for your help guys, I had done all that before but I may have used cheap pads. Jeff Quote Link to comment Share on other sites More sharing options...
deja Posted August 12, 2006 Share Posted August 12, 2006 Front callipers aren't frozen' date=' they function just not very good. Deja, I guess what I should have said is all systems are "functioning" I flushed the entire system when I put the car on the road about 3 years ago and it has always been this way, even prior to the SBC install. Is there a scientific way to check the master? I know it squirts out of both ports but not sure if the front is week. Same question for the proportioning valve? I figure the problem is with one of those items but am hoping to prove without just dumping money on swapping parts. Thanks Again Jeff[/quote'] No way I know of, but it sure sounds like master to me. PITA to swap out on a guess but its better than crashing your car in an uncontolled panic stop. BTW instead of that deserted road I'd do the testing in a big empty parking lot, much less stuff to hit. good luck, let us know when you figure it out. Quote Link to comment Share on other sites More sharing options...
Twoeightnine Posted October 19, 2006 Share Posted October 19, 2006 HICKL How did it go. Still good, still fighting it? Report please..... Quote Link to comment Share on other sites More sharing options...
HICKL Posted October 19, 2006 Author Share Posted October 19, 2006 Still sub par, put new pads, turned rotors and flushed brake fluid. Need to go thru the entire system just haven't done it yet. Jeff Quote Link to comment Share on other sites More sharing options...
Twoeightnine Posted October 19, 2006 Share Posted October 19, 2006 Got cha. Still wondering about the master cyl. A little spendy but, so is a non stop. I'll check back... Thanks. Quote Link to comment Share on other sites More sharing options...
gjc5500 Posted October 19, 2006 Share Posted October 19, 2006 Yea, sounds like it could be a MC thats going bad. like maybe the Oring in it has a crack or gouges(sp) in it. Quote Link to comment Share on other sites More sharing options...
Twoeightnine Posted October 19, 2006 Share Posted October 19, 2006 Yea, sounds like it could be a MC thats going bad. like maybe the Oring in it has a crack or gouges(sp) in it. Ditto. Quote Link to comment Share on other sites More sharing options...
Guest Mike Posted October 19, 2006 Share Posted October 19, 2006 I'd guess MC, PV, or pads... Quote Link to comment Share on other sites More sharing options...
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