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pull to left under braking


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At Summit Point last month, the car started pulling hard left under braking.

I found that the front left pads were wearing down quickly

and assumed a bad caliper. I've since replaced both front calipers

with rebuilts and the car STILL pulls left under braking. I

removed the ZX (I've got ZX discs in back) prop valve (right side

front line goes through it) thinking it might be blocked, car still

pulls left. I'll try removing the pressure switch next (device with

front and rear inputs from MC; front left, front right, and rear

outputs, has a wire coming out of it) as soon as I get a T-fitting.

 

Anybody got any other ideas?

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Guest Anonymous

Check your rubber hoses for blockage. If you dont already have them, switch over to braided lines. Flush system, rebleed and check it out. This is all I can come up with after everything else you have done. Maybe some else has a couple ideas.

 

Hope this helps

 

John

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"usually" the side it pulls too is working.. check the other side - defective caliper or ?

and dont forget to check the rears for binding or not working at all as well

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Thanks for all the replies.

Suspension seems OK, 90% certain it's the brakes.

Tire pressures OK

I have braided lines, will try swapping left to right

I think I voted Libertarian last election, so car shouldn't pull left or right

I'll check the rears, I wonder if the '82-'83 calipers require e-brake operation to keep them in adjustment (ebrake no hooked up on my car).

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Dan, the E-brake is what adjusts the rear brakes. Without the adjustment, you will soon find that the rear is not doing much at all in braking. Also, when you said you may swap left to right, if you meant the calipers, then remember that the bleed screw will be at the bottom when you do this. Also, one last item to ask about: did you resurface one of the front rotors but not the other recently?

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Guess I need to get the ebrake functional. Whole reason for the swap was so I wouldn't have to futz around w/ keeping the rears tight.

I was talking of swapping the lines, but then maybe the calipers too if the problem persists. I think there's a plug that can be swapped with the bleed screw, maybe?

Both rotors were resurfaced.

The left front rotor has been fully swept by the pads after a couple of days driving around, while there's still an unswept band on the right front rotor. Seems the caliper just ain't squeezin. Might hafta blow out the line.

 

Thanks again,

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Hey Terry, I thought the ebrake will only adjust the rear brakes if they are drums. If using the ZX disc brakes in the rear, they should be self adjusting. I believe Dan is using the ZX disc in the rear.

 

Please correct me if I'm wrong. I'd just hate to see Dan go through all the work of hooking up the ebrake if he does not need to.

 

Ruben

'72 240Z

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My self-rebuilt rear calipers would not auto-adjust. The ebrake would eventually stop working After hand adjusting, I did notice that the brakes worked better.

 

Seems crazy to make the normally automatic adjustment of the caliper dependent on the operation of the ebrake. But it wouldn't be the first boneheaded design from Nissan.

 

If you twiddle with the caliper, you can see it moving the piston closer and closer as you move the ebrake lever arm back and forth (like 20-30 times). That's if the thing isn't jammed up.

 

I'm not too happy with my ZX rear calipers.

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Yeah, if it's a 280ZX caliper, the e-brake adjusts it. but you can just yank the lever on/off a few times to get it adjusted up to rule that out.

 

BTW, teflon lined braided hoses can have the inner teflon liner break away from the hose and block the hose. This is why they have a minimum bend radius rating on those hoses. I've seen people do nasty things to those hoses (tie them in knots, let a caliper hang by them and putting a tight bend in the hose). I always cringe when I see that. I'd try removing the hoses and checking for this problem. Like Mike said, check the right hose - that's probably the side that has the problem.

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I think I got it. Replaced the right front SS line with an unused spare, and put in my new Carbotech Panther XP pads. Hey, it STOPS now! In a straight line to the parts store and most the way back. Then I *think* I might've detected a little left pull again, but nothing like what I had. Might just be crud in the line, maybe the act of replacing the line dislodged some of it? We'll see. Might hafta blow the lines out yet (I hope not).

 

Anyway, the resurfaced right front rotor has now been fully swept by brake pad, whereas before there had been a band of untouched resurfaced rotor, so I think I'm O-Tay.

 

The "82-'83 ZX rear calipers seem to be self-adjusting, as the left rear was tight despite no parking brake activity. The right rear not quite so tight. The right rear's piston notches are buggered up a bit, and partially blocked up with antisqueal (was that way when I bought the rebuilt rear calipers last year). I paid particular attention to ensure that the nub on the pad engaged one of the notches in the caliper piston. Might remove the left rear again to check that.

 

BTW, without the prop valve (from a ZX), the fronts seem to lock easily upon initial application. The valve must also have some delay action to the fronts, which makes some sense. Yes, the prop valve IS going back in. What a mess THAT's gonna be. Man I hate brake fluid.

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The way you describe the problem does sound like a hydraulic problem with the right side. The only thing I can add is to check your left side t/c rod bushing and torque. Any play there will cause diving while braking.

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Update:

After ruling out the prop valve, pressure switch, and flex lines, I drained the whole system and blew out the lines w/ compressed air. I also ground the metal plate backing the friction material on the pads, as there was evidence of some interference (although the pull to the left ocurred with two different sets of calipers and pads, so I don't think that was the problem).

 

Car ran/braked great at Mosport, won my class and set a new class record. On STREET tires (B'stone S03 Pole Positions). Woohoo!

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Originally posted by Dan Baldwin:

Update:

Car ran/braked great at Mosport, won my class and set a new class record. On STREET tires (B'stone S03 Pole Positions). Woohoo!

Hey, anybody else show up in your class? Bwah Hah.

 

You ready to move back south? Got some room for another stress weenie at the bomber plant...

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Hmm. I'm a bit-out-of-practice stress weenie that'd like to get back into that field. Bombers, that'd be cool. 2thumbs.gif But I don't want to move, although I like that area.

 

Dan, I have the B' S03s on my Eclipse daily driver and I really like them. Good thing I drive less that 5K miles a year! Those are some sticky street tires! Hardly what I'd think of as a daily driver tire!

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KAT, I might be 'bout ready. They're behind on paying me up here and I need two new Hoosiers (4 really). You busted me, bTW, only one other car in my class, a Dodge Shelby Omni (weighs ~ same as me, with ~270hp).

 

Oh yeah, that's stress wienER, I do have some self-respect left, though not enough to prevent me from considering Lock-Mart as an employer.

 

Sorry, Pete, they haven't built bombers there in a LONG time. B-29s (I think) back in WWII. They do build F-22s there, which could be considered pretty cool. Mainly C-130s. Rivet music all day every day, with two music breaks. No music on Sundays.

 

Dan

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