StockSS Posted June 1, 2010 Report Share Posted June 1, 2010 My brake pedal is fairly spongy and has been for quite some time now. I have stock brake lines and the power slot 14" rotor upgrade for the front. When I press on the pedal the booster deflects about a quarter inch. I though maybe it was the vacuum line coming in so I put a kink in it to test it out. By doing that the pedal became firm once again. So then I though it may be the "electronic thing the vacuum hose is connected to so I unplugged it with no change. What do you guys think it can be? Bad booster or bad master? I'll post up a video this evening to show the symptoms. Quote Link to comment Share on other sites More sharing options...
scootertrash19 Posted June 2, 2010 Report Share Posted June 2, 2010 Have you tried bleeding the brakes? I would try this first to see if it cures the problem, air in the system will cause this symptom. Also, a bad master cylinder will show up when you are sitting at a stop in gear and the pedal will continue to travel down toward the floor board. Usually a bad booster will be a hard pedal but no stopping power. Just a couple ideas. Let us know what you find! Quote Link to comment Share on other sites More sharing options...
70chevy03ss Posted June 2, 2010 Report Share Posted June 2, 2010 Stock brakes on these trucks are some what spongy anyways. Might also want to get stainless brake lines. Quote Link to comment Share on other sites More sharing options...
StockSS Posted June 7, 2010 Author Report Share Posted June 7, 2010 Well I ordered a set of Russel lines for my truck back when I did the Power Slot rotor upgrade, but the kit they sent me was not the right one. I received part number 672430 for 99-03 Silverado 4WD. The threaded ends are not the same as whats on the truck and their too short. Anyone know the correct SS lines to get and where? Also I haven't had time to bleed my brakes again to see if that is the problem. Hopefully I'll get to do this this week when I'm not doing homework. Quote Link to comment Share on other sites More sharing options...
Fireman31 Posted June 7, 2010 Report Share Posted June 7, 2010 Anyone know the correct SS lines to get and where? Earl's Hyperfirm Stainless Lines, Summit Racing part# EAR-28A640ERL Quote Link to comment Share on other sites More sharing options...
StockSS Posted June 7, 2010 Author Report Share Posted June 7, 2010 Earl's Hyperfirm Stainless Lines, Summit Racing part# EAR-28A640ERL Thanks. I did a search on Summit and that part number or variations of it did not come up. I did find the part number with thunderracing. Quote Link to comment Share on other sites More sharing options...
StockSS Posted June 12, 2010 Author Report Share Posted June 12, 2010 Well I re-bled the lines today and still have the same issue. I'll try to get a video up asap so you guys can see. Quote Link to comment Share on other sites More sharing options...
StockSS Posted December 26, 2012 Author Report Share Posted December 26, 2012 (edited) Old thread I know.... I'm about to purchase the Earl lines from thunder racing since the Russel 672430s did not work. Any chance you guys could hook me up with some part numbers for the hydro-boost stuff? I could just go to a junk yard and look around, but I might as well see what it all cost new. I'm hoping the hydroboost and the SS lines will take care of the spongy brake pedal issue. Edited December 26, 2012 by StockSS (see edit history) Quote Link to comment Share on other sites More sharing options...
rgp6373 Posted January 18, 2013 Report Share Posted January 18, 2013 i had this same issue of soft brakes and turned out to be the brake propotioning valve was siezed Quote Link to comment Share on other sites More sharing options...
StockSS Posted January 20, 2013 Author Report Share Posted January 20, 2013 i had this same issue of soft brakes and turned out to be the brake propotioning valve was siezed Can you elaborate on this for me? Where is it and how much are they approx? Quote Link to comment Share on other sites More sharing options...
Blown 346 Posted January 20, 2013 Report Share Posted January 20, 2013 Out of both of my SSS's I havent had this issue bot on my last SSS. It was caused by my master cylinder. Replaced it and the brakes became touchy, and stopped on a dime. Hope you figure it out. Im am by no means an expert on Braided brake lines. But Im pretty sure the brand names like Earls and Russel are pretty much built that same way minus the name you pay for. If your braking issue wasnt fixed I doubt that a different brand name line will fix the issue. It has to be somewhere else. In my situtation, my pedal started to feel soft and like it wouldnt respond like it once did. (It took more pressure on the pedal for the brakes to actually work) Your master doesnt have to be leaking for it to be bad and not working efficiently. My pedal would firm up as long as I let my foot off a little and pressed it again. If you press the brake while in Drive, and you push the pedal down further does it continue to travel?? If so, those are the symptoms I had and the new master for around $50 fixed my issue. FYI.... If you do end up replacing it, just make sure to clean the new master with brake cleaner first. Install it, hook up the lines ( not tight, just tight enough so you done leak) and fill the master. Have a buddy or someone press the brakes gently down until they get pressure and fill as needed. Have them hold the pedal down, slowly unscrew one of the lines off the master and bleed each line separately a few times. Make sure you have a towel underneath them as it will be messy. Wear safety glasses and old clothes. I had fluid spray all over me from the pressure behind the lines. Let us know if your new lines fix the issue. Quote Link to comment Share on other sites More sharing options...
ssfast Posted January 23, 2013 Report Share Posted January 23, 2013 You should bench bleed a master cylinder before putting it in the truck so you get all the air out! Then install and bleed the system you also have to be carefull with brake clean and rubber/plastic it can dry it out and make it brittle! What ever you do don't get brake fluid on the paint it will strip it off! Quote Link to comment Share on other sites More sharing options...
Blown 346 Posted January 23, 2013 Report Share Posted January 23, 2013 You can bleed masters either way. I find it easier to do it on the truck, if you dont have a vice. Quote Link to comment Share on other sites More sharing options...
StockSS Posted January 25, 2013 Author Report Share Posted January 25, 2013 Out of both of my SSS's I havent had this issue bot on my last SSS. It was caused by my master cylinder. Replaced it and the brakes became touchy, and stopped on a dime. Hope you figure it out. Im am by no means an expert on Braided brake lines. But Im pretty sure the brand names like Earls and Russel are pretty much built that same way minus the name you pay for. If your braking issue wasnt fixed I doubt that a different brand name line will fix the issue. It has to be somewhere else. In my situtation, my pedal started to feel soft and like it wouldnt respond like it once did. (It took more pressure on the pedal for the brakes to actually work) Your master doesnt have to be leaking for it to be bad and not working efficiently. My pedal would firm up as long as I let my foot off a little and pressed it again. If you press the brake while in Drive, and you push the pedal down further does it continue to travel?? If so, those are the symptoms I had and the new master for around $50 fixed my issue. FYI.... If you do end up replacing it, just make sure to clean the new master with brake cleaner first. Install it, hook up the lines ( not tight, just tight enough so you done leak) and fill the master. Have a buddy or someone press the brakes gently down until they get pressure and fill as needed. Have them hold the pedal down, slowly unscrew one of the lines off the master and bleed each line separately a few times. Make sure you have a towel underneath them as it will be messy. Wear safety glasses and old clothes. I had fluid spray all over me from the pressure behind the lines. Let us know if your new lines fix the issue. Thansk for the info guys. I never used the Russell lines since they would not thread into the hard lines on my truck. Pitch was way off. I haven't had a chance to install my new SS lines yet, but will soon. I'm also going to go paruse the salvage yards for a hydroboost set-up. Quote Link to comment Share on other sites More sharing options...
Bgreenard Posted February 2, 2013 Report Share Posted February 2, 2013 I'm interested in your outcome, having similar problems. Quote Link to comment Share on other sites More sharing options...
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