adamzan Posted October 23, 2009 Share Posted October 23, 2009 Ok I had a leak somewhere when I first got this truck, and simon was right about it being the wheel cylinder. I had a shop replace it and the brakes were good again. I changed the rotors and pads last september because the rotors had a lot of uneven pad deposits or were warped. In may magregor fixed my frame and showed me hot to change the other rear wheel cylinder plus the rear shoes and springs. So I've got a "new" brake system. Right? It doesn't feel like it. I cleaned and lubed the slide pins as per the how-to, they were in great shape but I did it anyways. I had been noticing before the rear shoes were changed that the pedal had to be pushed really hard to stop the truck. This was different from when I had the shop do the wheel cylinder as they were nice back then. So basically right now my pedal goes down about 1/2 way and hits a kinda hard spot. I'm still losing fluid too! Not much but its about 1/4 inch below the MAX line yet I filled it just before labor day weekend. Any ideas? I'm hoping its nothing expensive. I don't see any leaks at the calipers and I checked the brake lines on the frame and rear end, they are nice and solid. I don't have much money (what student does) and it is my only mode of transport without borrowing another car. I know I shouldn't be expecting rear disk like performance but even my friends who've driven it have commented about how much the brakes SUCK! TIA guys. Link to comment Share on other sites More sharing options...
Terrano1992 Posted October 23, 2009 Share Posted October 23, 2009 I suspect worn/leaky master brake cylinder first. And vacuum brake booster as second option. Check R-ABS also, if you have it. Link to comment Share on other sites More sharing options...
Simon Posted October 23, 2009 Share Posted October 23, 2009 I doubt you're losing fluid. The fluid level will go down as pads and shoes wear. Try adjusting the rear shoes, as something could be stuck, or way out of adjustment, and also ensure that your plungers on your calipers are sliding freely. I'll second the suggestion of checking the R-ABS, as mine was causing some weird braking issues lately (hard pedal, then NO pedal pressure) until I pulled the fuse. I haven't had time to look into the issue yet, but it's been fine since I pulled the fuse for the ABS. Link to comment Share on other sites More sharing options...
andreus009 Posted October 23, 2009 Share Posted October 23, 2009 (edited) Any chance you drove it around some with the parking brake slightly engaged? If the rear shoes make sufficient contact with the drum while driving they will get hot and glaze. I did this to myself when offroading and in 4x4 lo range. Didn't even realize it was on until I saw the light. Duh! Anyhow, just got done doing rear brakes on mine and it is definitely braking better/faster. I guess if I was on a budget and suspected this problem I would lightly sand shoes and drums with a high grit sandpaper. Probably 300 or higher. I second the inspection of the rear brakes because if the fluid went down by 1/4" from wear in that seems like a lot in my opinion for a 2 month time frame. Edited October 23, 2009 by andreus009 Link to comment Share on other sites More sharing options...
GrimGreg Posted October 23, 2009 Share Posted October 23, 2009 Are the brakes fully locked up when the pedal gets stiff? You might just have things adjusted so tight that you don't need much pedal to stop. Which could account for the drop in fluid level, since you are probably burning off brake material quickly. Usually if there is a leak, the pedal will get soft, not stiff. Link to comment Share on other sites More sharing options...
5523Pathfinder Posted October 24, 2009 Share Posted October 24, 2009 You changed the other wheel cylinder? Did you bleed them afterwards? Im going with neediung to adjust the cylinder. Adjust until the drum barely slides over a bit snug, them back it off a touch. Link to comment Share on other sites More sharing options...
adamzan Posted October 25, 2009 Author Share Posted October 25, 2009 Thanks for the suggestions. Derek, when the wheel cylinder got changed we crimped the rubber line going to the rear end and only bled the new WC. I don't know if that was the wrong way or not! Nismojunky is here right now and he is gonna take it for a spin tomorrow and see what is up. I will also pull the abs fuse. Another Q, are the rear drums supposed to self adjust? And if so is it by hitting the brakes in reverse or by using the handbrake? Link to comment Share on other sites More sharing options...
Kingman Posted October 25, 2009 Share Posted October 25, 2009 Should be by jabbing the brakes in reverse and spinning the little star gear inside the drum. Link to comment Share on other sites More sharing options...
adamzan Posted October 28, 2009 Author Share Posted October 28, 2009 (edited) Gonna try bleeding the brakes, cleaning the slide pins again, and check my calipers and drum adjustment again this weekend. If that doesn't do it I'll have to look into the MC or the booster. It veers to the right when braking...turns the wheel on you! I replaced the brakes last year and I bet that one side is worn down to nothing already. Btw I tried pulling the ABS fuse for my drive home, and there was no difference. At least that is ruled out. Edited October 28, 2009 by adamzan Link to comment Share on other sites More sharing options...
GrimGreg Posted October 28, 2009 Share Posted October 28, 2009 If it pulls, it is braking more on the front side it pulled toward. Take apart the opposite side and make sure the piston in the caliper isn't froze up. Link to comment Share on other sites More sharing options...
adamzan Posted November 4, 2009 Author Share Posted November 4, 2009 Also I have another symptom to report. If you're stopped like in park or something, and you stomp on the brakes a few times the idle starts the fluctuate and the truck sounds like its gonna stall... I didn't have time to look at it this weekend though Link to comment Share on other sites More sharing options...
msavides Posted November 4, 2009 Share Posted November 4, 2009 Also I have another symptom to report. If you're stopped like in park or something, and you stomp on the brakes a few times the idle starts the fluctuate and the truck sounds like its gonna stall... I didn't have time to look at it this weekend though the last bit of info would point to the vacuum brake booster. It is the only thing that would effect the engine running. Perhaps a bad check valve in the brake booster. Link to comment Share on other sites More sharing options...
GrimGreg Posted November 4, 2009 Share Posted November 4, 2009 Yeah, that is vacuum, but even working properly you are going to make the engine flutter by pumping the brakes while stopped and idling. Link to comment Share on other sites More sharing options...
adamzan Posted November 26, 2009 Author Share Posted November 26, 2009 (edited) Ok, here is an update. I replaced the front brake calipers, rear brake drums (chunks of mine kept coming off and the parts truck had 2 like new ones, so I machined them) and bled the entire system. I can stop pretty damn good now! But I do have one concern. The pain on the booster right below the master cylinder is all peeled off and there is rust under there. I'm not concerned about the rust but the fact that this area was wet. I am not losing any more fluid so far. Also I noticed that there is a hole in the MC right in between 2 of the lines that was wet, and bubbles were coming out of it while I did the bleeding, what is that for? Edited November 26, 2009 by adamzan Link to comment Share on other sites More sharing options...
Precise1 Posted November 26, 2009 Share Posted November 26, 2009 Hydraulic fluid eats paint so there was a leak there previously (still?). Sand and primer it and forget it. Post a pict of what you are talking about please. B Link to comment Share on other sites More sharing options...
Alkorahil Posted November 30, 2009 Share Posted November 30, 2009 Brake Booster Check valve? Something people forget about that should be replaced when vehicles get old. I replaced mine for giggles cuz we had one laying around about to be returned to Nissan and was surprised how much more responsive my brakes got. Link to comment Share on other sites More sharing options...
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