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Smoking brake

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nick
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Smoking brake

Postby nick » 18 Jun 2009 21:39

The brakes were operating normally. The pads are good and the rotors look OK. After the second of two stops I smelled hot brakes. So I pulled off the road and found the passenger (US) side smoking. After some cooling I set off again and found that at brake application the car pulls hard to the left, opposite side to the smoking brake. I removed the right brake pads and scuffed them with fine sand paper. Now the right brake is normal. I don't think the scuffing was the fix. Can anyone diagnose why the pads hung and can I expect this again.

nick

After re-reading the above I realized I had said the car pulled right. I meant left so I edited that line.

humanoid
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Postby humanoid » 19 Jun 2009 00:41

Stuck piston maybe?

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Underdog
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Postby Underdog » 19 Jun 2009 00:48

I'd vote for a sticky piston also. You would have probably moved the piston a bit in the course of removing & installing the pads. If you forced the piston back that would acount for the brakes being freed up. Any chance it's been sitting a while?

I've always heard stories of hoses collapseing but never witnessed it myself.

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Periwinkle
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Postby Periwinkle » 19 Jun 2009 01:39

Hi Nick,

I think the gentlemen are correct. It certainly sounds like a sticking caliper piston. Same thing happened to be two summers ago, only on the driver's side. The caliper had to be refurbished.

Let us know what you find. Good Luck.

Sue

aka Peri


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FI Spyder
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Postby FI Spyder » 19 Jun 2009 01:59

Happened to my Integra, rear pads were riding hard on rotors and squealing/noisey. Metal ring that holds the rubber seal in place rusted and in turn rusted the pistons so the were sticking and not releasing. Cost of rings and rubbers...$6... costs of pistons $60... easy peasy except no one stocked the pistons. Only available as rebuilt calipers....cost $400 less $100 core charge.

Your pistons/rubber/retainers probably need replacing. Will be cheaper than the Integra.



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Hasbeen
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Postby Hasbeen » 19 Jun 2009 02:01

Nick, you could of course, have got some oil, or fluid on the disc,
or pads on that side, & cooked it into the pads, causing the
problem, but unlikely if this was not obvious when you were working
on it.

If the car has not been used for some time, the pistons could have
stuck to the rubber seals, in that calliper, & caused some over
heating, but probably not as much as you discribe.

Don't discount a deteriorating brake hoses, if they are old. The
high pressure of brake application will get through a degraded hose,
but the low pressure of the return springs, on drum brake shoes, or
disc on pad, may not. How long have they been on the car?

I have twice had old hoses cause the brakes to drag, & get a bit hot.

Once was with my 7, just after it went back on the road. I had fully
overhauled the brakes. I did everything else, but somehow failed to
fit the new rear hose. A loss of performance, & a hot smell, after a
short drive, [no smoke] indicated dragging rear brakes.

I also had it happen with the front brakes on an old Datsun
1.5 tonner.

Carry a spanner that fits the bleed nipple of that disc. If you have
the problem again, just crack the bleed nipple, on that calliper, [&
only that calliper]. If a restriction is holding line pressure,
fluid will squirt out, [rather than dribble out], & the brake will
become free. If neither happen, the hose is not at falt.

Hasbeen

nick
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Postby nick » 19 Jun 2009 17:43

Checking my service records, the previous owner had rebuilt the calipers about 10 years ago. The car has been used regularly and the brake seems to be operating normally since I removed the pads for inspection. My concern is that if I had the problem once it will likely return. I think I'll rebuild the calipers again and inspect the brake lines.

nick

Underdog
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Postby Underdog » 19 Jun 2009 20:43

Sounds like a good plan. Not to be spending your money but would be a great time to do a set of braided stainless hoses.

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Hasbeen
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Postby Hasbeen » 19 Jun 2009 23:14

Nick, one advantage of stock rubber brake hoses is that it's easy to
check their condition, from the outside.

Bend your hose around about a 3" [75mm] circle, & inspect the
outside of the bend.

If you can see any small cracks in the rubber, running around the
hose it's time to replace them. If you can see a lot of cracks, it
was time to replace then quite some time back.

When I replaced my offending hose, I pushed a brazing rod through
the thing, & got about half a tea spoon of black gunk, with about
the consestency of silicon gasket goo.

Hasbeen

busheytrader
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Postby busheytrader » 20 Jun 2009 07:47

I thought from the thread title, this was going to be "who's smoked their std 7 brake pads and boiled the brake fluid?"

Me. Twice [}:)]


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bmcecosse
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Postby bmcecosse » 20 Jun 2009 20:40

The pads that 'overheated' will now have a different coefficient of friction to the unheated pads. Best swop the pads about - putting on from each side on the other side, if you see what I mean - and take the chance to push each piston back into the caliper as you go - to check they are free moving.

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