There are a few possible causes of disc brakes dragging.
One, as Bob mentioned, is the rubber hose to that caliper swelling
internally as it ages - it restricts fluid flow, and may eventually
fail completely with disastrous results. Replacement rubber hoses
aren't very expensive, and a set of teflon steel-braided hoses that
will replace all three or four rubber brake hoses on your car can be
had for less than $100. Putting them in is messy, since brake fluid
will drip everywhere, but otherwise it's not too bad.
To diagnose this problem, I would let the car sit on jackstands for
upwards of an hour without pressing the brake pedal, and see if the
brakes still drag - if they do, this may not be your problem. If
they don't, it would seem to indicate that the pressure had time to
relieve through the restricted hose - replace the hoses.
A loose wheel bearing could cause this problem, too, as the wheel
(and brake disc) could shift far enough to rub against the brake
pads. To diagnose this, put the car up on jackstands and grab the
wheel at the 12 and 6 o'clock positions. See if you can move it
appreciably, rocking back and forth. Some movement may be due to
slop in the suspension bushings - look to see if the suspension
upright is moving with the wheel. If it is, then the suspension
bushings may be worn. If the wheel moves significantly, but the
upright does not, then you need to attend to the wheel bearing(s).
You may simply be able to tighten them up, or you may need to replace
them completely.
Another is the pistons in the caliper sticking - normally, they pull
back slightly when you take your foot off the brake pedal and the
spring on the pedal and in the master cylinder push the MC piston
back. Hardened dust boots around the caliper pistons may cause this;
it could also be dirt and/or corrosion on the surface of the pistons
themselves. Repairing this is a little more involved, as it requires
removal and partial disassembly of the calipers, but it's still not
too bad.
There may well be other things I'm not thinking of, but these ought
to get you started. None of them are terribly expensive or
time-consuming to remedy, just messy.
HTH!
Dan
At 23:06 -0700 10/9/01, Kurtis wrote:
>Thanks Bob...
>
>I discovered the problem when I had both front wheels off the ground. The
>front left spins with slight dragging (that I would expect). The front left
>with noticeably more. It will spin maybe one revolution and a half if I
>give it a good hard spin.
>
>Thanks for the info!
>
>Kurtis J.
>1963 TR4
>
>----- Original Message -----
>From: "Kinderlehrer" <kinderlehrer@mindspring.com>
>To: "Kurtis" <kurtisj@cox-internet.com>; "Triumph List"
><triumphs@autox.team.net>
>Sent: Tuesday, October 09, 2001 8:11 PM
>Subject: Re: Brake Question
>
>
>> Kurtis,
>>
>> You're not missing anything, there is no adjustment on disk brakes. How
>did
>> you make this discovery? If you happened to have the wheel off the ground
>> and could hear the pad scraping the rotor when you spin the wheel, that's
>> normal. If the car keeps wanting to make a right turn when you want to go
>> straight, that's not. Using this list as a measuring device, I'd say the
>> most common culprit for the later condition is an over age flexible hose
>to
>> the front wheel cylinder. But hey, that's just my opinion, I could be
>> wrong.
>>
>> Bob
>>
>> ----- Original Message -----
>> From: "Kurtis" <kurtisj@cox-internet.com>
>> To: "Triumph List" <triumphs@autox.team.net>
>> Sent: Tuesday, October 09, 2001 10:08 PM
>> Subject: Brake Question
>>
>>
>> > Okay everyone... I have another dumb question. I discovered today that
>my
>> > front right brakes are dragging. I hate to sound as dumb as I really
>am,
>> but
>> > how the heck do I adjust this???
>> >
>> > I have the Bentley Workshop Manual, and it gives clear instructions for
>> > removing and replacing the pads, but it doesn't really go into any
>detail
>> > regarding adjustments. I feel comfortable removing and replacing the
>> pads,
>> > but what do I need to do to insure they don't continue to drag?
>> >
>> > As always, any and all help is greatly appreciated.
>> >
>> > Kurtis J.
>> > 1963 TR4
--
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Dan Buettner - Des Moines, Iowa - mailto:danb@thelittlemacshop.com
1957 TR3, TS15098L 'O' - awaiting owner's time and money.
1977 Spitfire, FM64159U 'O' - in storage.
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