Turborusty Posted July 23, 2009 Report Share Posted July 23, 2009 shoulda gone steel braided for no flex. Turborusty Link to comment Share on other sites More sharing options...
Shelby Posted July 23, 2009 Report Share Posted July 23, 2009 ALL flex brake lines are steel braid'd , oem or after market Link to comment Share on other sites More sharing options...
Chad Posted July 23, 2009 Author Report Share Posted July 23, 2009 Got all the new lines in (fornt and rear), it's better but still a tad more squishy than I'd like. I'm used to my 2 door tahoe, and this 98 is a 4 door, so I'm dealing with a curb weight of 4825 vs 5330 pounds, so I'm probalby expecting too much of it. They use the same brakes but this 98 is 500 pounds heavier. I cut the old lines in half, they are a double nylon braid. I decided to drive this a few hundered miles and re-adjust the rear drums, then I'll decide if I want to put in braded stainelss. It's not a hard job to do, but that's another $70 and 2 hours I don't want to spend if it's not going to help anyway. I bled off the boster on both tahoes and compated pedal responce, the 97 2 door that I'm used to is only ~15% stiffer than this 98, so I'm thinking I have it all setup and installed right, I think it's just a difference in expectation/weight, and a possible difference in brake line quality. I bedded the pads in today and will dirve it a little more before I make up my mind. Link to comment Share on other sites More sharing options...
Shelby Posted July 24, 2009 Report Share Posted July 24, 2009 I cut the old lines in half, they are a double nylon braid. your kiding me,, i have never heard of such a thing , thats like makeing a built in failure point ,,whats the american car makers trying to do Link to comment Share on other sites More sharing options...
Chad Posted July 24, 2009 Author Report Share Posted July 24, 2009 yah, it's making me think this will happen with the replacement lines I just got, they'll probably fail in the same way some day soon. I cut the old ones right in half with a razor knife. I know from experiance that braided stainless lines fles a little too, moslty the nylon liner flexing till it's hard up against the stainelss braid. Link to comment Share on other sites More sharing options...
mikec Posted July 24, 2009 Report Share Posted July 24, 2009 GM antilock brake actutators also have a nasty failure mode: a small sliver of grit, or more commonly a metal shaving from some other carelessly built/installed brake piece, can jam the ABS actuator. This puts it in basically "bypass" mode which feels just like a master cylinder that won't build pressure. Really sloppy brake pedal. Unplugging the electrical inputs to the actuator doesn't help; the problem is the actuator is physically jammed. This was common on mid to late-80s vintage GM trucks/vans; I don't know if the later 90s stuff has the same setup. mike c. Link to comment Share on other sites More sharing options...
Chad Posted July 24, 2009 Author Report Share Posted July 24, 2009 with the soft lines pinched right next to the hard line conector, the peddal is unmovable after you get it where it's just past bleed-back part of the MC bore. I think it's the soft lines and/or calipers/drums. I re-tested the ABS, all 3 channels seem to work proppely and independantly. I verified the front calipers are floting propperly with a good tug/push. Link to comment Share on other sites More sharing options...
Shelby Posted July 24, 2009 Report Share Posted July 24, 2009 i wonder when they start'd useing those brake hoses,, i know i've been out of the shop for a while , nearly 10 years but i have never seen a non steel wrap'd brake hose that i knew about Link to comment Share on other sites More sharing options...
Shiltron Posted July 24, 2009 Report Share Posted July 24, 2009 I did not read all the replies you had but can I assume you have the rear brakes properly adjusted? Is the shoe contact with the drum good? Is the drum surface flat? I would make sure you've checked the basics before involving any aspect of the ABS system. Check for proper rear shoe adjustment. Also loose wheel bearings can cause caliper pistons to travel further, resulting in a more spongy pedal travel. I have seen people put the calipurs on upside down with the bleeder screw on the bottom. They cannot be bled this way. There are two different master cylinders that will fit these models. They look identical on the outside but are different on the inside. If it is supposed to have the HD master on it and you put the light duty unit on, it will have a mushy pedal. As a side note.......You can damage rubber brake hoses by pinching them with vicegrips. Hope this helps. Link to comment Share on other sites More sharing options...
Turborusty Posted July 24, 2009 Report Share Posted July 24, 2009 i wonder when they start'd useing those brake hoses,, i know i've been out of the shop for a while , nearly 10 years but i have never seen a non steel wrap'd brake hose that i knew about 12 years ago, my '88 Dakota blew out one of the rubber hoses while I was driving it.......yeah, fun stuff. But it was nylon braided as well, no steel in it anywhere. Turborusty Link to comment Share on other sites More sharing options...
Chad Posted July 24, 2009 Author Report Share Posted July 24, 2009 Yah, I only pinched the old hoses, knowing they were going to be replaced anyway. I'll re-check the shoes, they were loose the first time I checked them so I tightened them up. I'll check again now that they are beded in. I'll also check the bearings, the front seem to wander a little when I firt picked it up, I put on new tires and' it doesn't wander anymore, but that coudl still be a problem. I can see how when it tweaks/deflected to the side, it would change the needee fluid for propper engagement, but this problem exists even when it's not in motion with no wheels mounted. I ran the rear in the air and could hear the drums drag just a little and no sounds like warpage (I've seen, heard warped rotors on stands before). Caliper are on right Link to comment Share on other sites More sharing options...
Chad Posted July 24, 2009 Author Report Share Posted July 24, 2009 actualy, stock quest hoses are nylon too, sometimes when I'm parting a car out, I jsut cut the brake hoses to get the hubs out in one piece. I just use shears, they cut easily. Link to comment Share on other sites More sharing options...
Ernie88TSi Posted July 25, 2009 Report Share Posted July 25, 2009 Chad, did you turn the drums in the rear? When you had it all apart, did you notice if there was a lip on the edge of the drum? Link to comment Share on other sites More sharing options...
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