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Update on brake problem


Guest bastaad525

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Guest bastaad525

Well I'm a lazy bastard. I got tired of fiddling with the car and decided to take it to a shop. I'm pretty friendly with the guys at the local Midas here, so brought it there to have them check it out. They bled all four corners again, doing it the way I thought *I* SHOULD have been doing it, that is, they would pump the pedal 4-5 times, then hold it down, THEN open the bleed valve for a couple seconds and close it before releasing the pedal, as opposed to opening the bleed valve and then pumping the pedal with it open as the Haynes says to do. So that's how I'm going to to it from now on. That's how I've always done my clutch and that always seems to work....

 

While they had it up I asked them to inspect my rear brake shoes and the drums... I haven't had them off in a long time, I tried to take them off last time I bled the brakes but they were pretty well stuck on and I didn't want to mess with them (me being lazy again).

 

Anyways, the shoes weren't too worn out, BUT they were worn pretty unevenly, as were the insides of the drums. So I had them replaced and drums resurfaced, and of course they adjusted the wheel cylinders, which it seems they were pretty badly out of adjustment.

 

Well I'm happy to report that all this seems to have (mostly) fixed the problems I was having. The pedal is no longer way-too-soft, the car stops MUCH better now, and I was actually able to lock the tires when I slammed on them once.

 

There were a few problems... first was they adjusted my parking brake WAY too tight (it's always been very loose so they were trying to compensate and adjusted it like a new cars lever would be... 3-5 clicks on the handle to lock the rears). I didn't realize this till I got it home and parked in my spot, which is on a bit of an incline... usually the car will roll back w/o the parking brake, but this time it wouldn't. Then I tried to push the car by hand, and I coulnd't move it! So I loosened it up a bit. No big deal except I wonder what (if any) damage or wear I just put on my new shoes driving it 4 miles home basically with the rear brakes semi locked the whole way?

 

 

second problem is that though the pedal feels much better, I still get the problem with the wheel jerking a little to the side if I jab the brakes. Again I will mention though, that under steady braking, even steady HARD braking, it does NOT pull to the side, only that initial jerk when I first hit the pedal.

 

Question - could a slightly restricted hard line going to one of the calipers cause some kind of 'delayed reaction' in one of the calipers, and that would be why the wheel jerks just for an instant while that caliper 'catches up' to the other one? If I apply the brake normally instead of 'jabbing' them, it doesn't do it at all.

 

the reason I ask is that when I replaced the calipers, as hard as I tried not to, I ended up damaging one of the little S shaped hard lines that bolts directly to the caliper. I had a place make me a new one, but I noticed that the inner diameter was lessened a bit when the made the double flare, I'd say the inner diameter was reduced by maybe 30% versus the size of the stock piece it replaced. So maybe it just takes that fraction of a second longer for the pressure to get thru that line to the caliper... what do you guys think?

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Well I'm a lazy bastard. I got tired of fiddling with the car and decided to take it to a shop. I'm pretty friendly with the guys at the local Midas here' date=' so brought it there to have them check it out. They bled all four corners again, doing it the way I thought *I* SHOULD have been doing it, that is, they would pump the pedal 4-5 times, then hold it down, THEN open the bleed valve for a couple seconds and close it before releasing the pedal, as opposed to opening the bleed valve and then pumping the pedal with it open as the Haynes says to do. So that's how I'm going to to it from now on. That's how I've always done my clutch and that always seems to work....

 

While they had it up I asked them to inspect my rear brake shoes and the drums... I haven't had them off in a long time, I tried to take them off last time I bled the brakes but they were pretty well stuck on and I didn't want to mess with them (me being lazy again).

 

Anyways, the shoes weren't too worn out, BUT they were worn pretty unevenly, as were the insides of the drums. So I had them replaced and drums resurfaced, and of course they adjusted the wheel cylinders, which it seems they were pretty badly out of adjustment.

 

Well I'm happy to report that all this seems to have (mostly) fixed the problems I was having. The pedal is no longer way-too-soft, the car stops MUCH better now, and I was actually able to lock the tires when I slammed on them once.

 

There were a few problems... first was they adjusted my parking brake WAY too tight (it's always been very loose so they were trying to compensate and adjusted it like a new cars lever would be... 3-5 clicks on the handle to lock the rears). I didn't realize this till I got it home and parked in my spot, which is on a bit of an incline... usually the car will roll back w/o the parking brake, but this time it wouldn't. Then I tried to push the car by hand, and I coulnd't move it! So I loosened it up a bit. No big deal except I wonder what (if any) damage or wear I just put on my new shoes driving it 4 miles home basically with the rear brakes semi locked the whole way?

 

 

second problem is that though the pedal feels much better, I still get the problem with the wheel jerking a little to the side if I jab the brakes. Again I will mention though, that under steady braking, even steady HARD braking, it does NOT pull to the side, only that initial jerk when I first hit the pedal.

 

Question - could a slightly restricted hard line going to one of the calipers cause some kind of 'delayed reaction' in one of the calipers, and that would be why the wheel jerks just for an instant while that caliper 'catches up' to the other one? If I apply the brake normally instead of 'jabbing' them, it doesn't do it at all.

 

the reason I ask is that when I replaced the calipers, as hard as I tried not to, I ended up damaging one of the little S shaped hard lines that bolts directly to the caliper. I had a place make me a new one, but I noticed that the inner diameter was lessened a bit when the made the double flare, I'd say the inner diameter was reduced by maybe 30% versus the size of the stock piece it replaced. So maybe it just takes that fraction of a second longer for the pressure to get thru that line to the caliper... what do you guys think?[/quote']

I would be surprised if the hard line were the culprit, never seen that before. I made new hard lines for mine, but I did both sides at the same time. BTW I think the solution would be to go have that shop make another new line for the other side because I never have any luck getting the old ones off. At least you'd have two identical new ones.

 

Sounds like the problem was that they never got fully bled. Kind of hard to tell because adjusting the rears would make the pedal harder too, so it's tough to say whether it was one or the other that made the pedal feel better. If it was the bleeding then that means that there could have been water or air in there, which could have caused your previous problem.

 

Another thing that can cause the jerk when you first step on the pedal is dead TC rod bushings. If the bushings are gone when you step on the brakes the control arm will move back towards the rear of the car until something stops it. You might want to check those bushings. Otherwise it sounds like you should be good to go.

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Guest bastaad525

huh... NOW you guys tell me! I've possibly been chasing my tail for nothing then. I already knew my bushings were not in the greatest shape :D Just odd though because I can't say I ever noticed this problem with the wheel jerking until after I changed the calipers. Then again I wasn't LOOKing for any problems before then so it's possible it was there all the time.

 

Alignment seems PERFECT though, the car tracks perfectly straight when I'm on a level road.

 

And them replacing and adjusting the rear brakes stiffened up the pedal a LOT. Unfortunately it was a false hope... they had simply adjusted the E-brake WAY too tight. I adjusted and readjusted it a few times to get it just right... the way they had it I couldn't even turn the tire by hand with the E-brake all the way off. I noticed afterwords that the brake pedal was not nearly as stiff as it was yesterday. Still doesn't seem as bad as it was before they did the rears though.

 

I won't know if my problems are completely solved until I put the brakes to the test again then. They seemed fine before too until I got on them hard one time....

 

I'm probably going to reswap out the pads for a good set of pads though... I'm really not happy with how these are performing and I'm still getting brake squeal which is driving me nuts. I may also flush the fluid and go to DOT 4 or 5.

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Guest bastaad525

well after a couple days of driving it definately seems much better, even after a couple moderately hard stops, the pedal never softened up on me. So all problems SEEM solved except for that initial jerk of the wheel, which I"m now pretty sure has nothing to do with the brakes anyways.

 

 

After a little more breaking in I will put the brakes truly to the test and see what happens.

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Guest bastaad525

whoohoooo finally I can lock my tires again! Slammed them hard on the way to work going about 35 and sounded to me like all four locked up but of course it was hard to tell. Was definately the fronts though at least, I kept worrying that only the rears would lock for some odd reason. Anyways the pedal felt fine after the hard stop, didn't soften up at all.... I hope this means an end to my problems :)

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glad to hear it.

 

So it's the different bleed method used by the shop that corrected your brake problem? Did you replace anything to fix the problem with the car veering to one side when using brake?

 

My 280Z did that(pull to one side under braking) before I stripped it so I might have to deal with that sometime later on.

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Guest bastaad525

I don't know if it was the way they were bleeding it... it sorta makes sense to me, because the way the Haynes manual says to do it (pumping the pedal with the bleed valve open) could still result in air getting back into the system... yeah you've got a hose submerged in fluid, but air could still get sucked back in thru the threads of the bleed valve... I thought of that even the first time I did it, but I figured "hey if the Haynes manual says so".

 

 

As I said I've ALWAYS bled my clutch pedal using the 'pump, hold, THEN release the valve' method, and it's always worked perfectly for me.

 

 

So that MIGHT have been what fixed it, or it may just have been them replacing or more importantly, adjusting my rear shoes. While the shoes they replaced weren't too badly worn, they were worn oddly, in more of a slight oval than perfectly round, and the drums were worn like that as well. Also the guy said they were pretty badly out of adjustment (the wheel cylinders).

 

Now why it only seemed to get bad and cause a problem AFTER I changed the front calipers and pads, I don't know.

 

As for the wheel jerking a little to one side on hard braking... no that problem is still there, though Tim240z and a couple other guys mentioned this could just as easily be suspension related.... and my bushings are VERY worn so I dont' doubt it one bit :D

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