My barge has the wobbles

[rustyP]

For reference, it's an Auto 1994 Aristo, with the standard brake system on it (not upgraded to supra big boys)

Quick history:
When i got it imported not more than 4 months ago, I had all the discs machined n they were running pretty low, but still OKish.
Was heading to work yesterday, n runnin particularly late. Then forgot I had left somethin at home.. braked pretty heavy, headed home, got my stuff, ran back off to work givin it a fair bit.
Was doing about 110 down this highway and the yellow light comes on (at intersection with a camera), so I had to hit the brakes pretty hard again as from experience the yellow there is very short lived, and the limit at that section is 70 so yeah, basically, had to hit them pretty hard. Didn't trigger ABS or anything butstill stopped pretty quick.

Anyway, about another km or two down the road, the steerin starts to shake a bit... Now the last time this happened, I had blown a tyre... so I slowed... but when I slowed it kinda got better rather than worse.
So I kept going, and it progressively got worse til it was just about making me dizzy from the vibrations. I pulled over, checked all my wheels they all seem fine.. all the wheelnuts done up tight.
Continued on (by this time about 15mins late for work n still 5mins away), but kept it to around 70 (on the 100kmh road, ppl going around me)...
Anyway, got to work, parked and was at work for 8hrs and left it there worried about what the fark I had done to it last time I had the back wheels off that morning.

Kinda came to the conclusion it was probably the discs warping from the hard braking I had done earlier.
When I left work to go home, it was all a-OK... no vibrating, no noises.. all good.
Deliberately kept off the brake this time, to try and not heat it up and warp the disc/s again.
Only this time, It still got bad again, but I had barely touched the brake at all.
Had to baby it home, and before I get out there and try to pull stuff apart, figure I'd shout out and see if anyone can help.

So facts are:
Seems to definately be heat-related.. driving for a while, gets worse.
Also seems to be brake related.. more braking = gets worse.
And the clincher:
When I pulled in at home, checked the wheels over.. they all seem good except the front left which smells like it's on fire, and I can barely touch it for fear of burning the rim polish/rubber into my skin.

So to me, i'm thinking the caliper has someone stuck onto the disc and is gettin damn hot just driving it around.
Does this sound likely? Am I on the ball?
Would this be because of hard braking earlier? (Obviously its related, im asking if it's directly causative)?
Would it be because the discs are too thin? (Will I need new discs?)
If i do need new discs, where's the best place to get "decent-but-no-brembo" items?
Is it something I'm going to be able to "fix" with my fairly limited tools and space/time constraints? I'm reasonably handy, but not very experienced.


Help?

Thanks heaps guys!

[Vios-GT_07]

sounds like the brake calliper has seized somewhere.. did it feel slower at any point? (off boost)

with ventilated discs, as soon as u take your foot off the gas the disc should cool down.. so driving normally with foot off the brake should result in a cooled down disc

hm... how good are your brake pads? could be they're pretty thin and chewing into the disc? that could cause the heat issue and explain the wobble..

and no, no matter how hard you drive unless u totally intend to abuse it by riding the brakes and what not, it'll be alright

[thechuckster]

When I pulled in at home, checked the wheels over.. they all seem good except the front left which smells like it's on fire, and I can barely touch it for fear of burning the rim polish/rubber into my skin.

if the rim is extremely hot then also check the front bearings

the heat could be those bearings girinding them selves into a metal slurry.

[rustyP]

if the rim is extremely hot then also check the front bearings

the heat could be those bearings girinding them selves into a metal slurry.

dOH!
Not what I wanted to hear!!!

Thanks for the headsup though, will definately check.

That is, if someone can give me a quick how-to on checking wheel bearings?

[xman]

Jack the offending wheel up and give it a wobble. Side to side and up and down. If it moves move than 2 or 3 mm in both directions the bearing is on the way out!

[rustyP]

I thought that was what you do to check if your ball joints are fubar?
(double wishbones)

[xman]

Yes, you can check the other bits that way as well.
If you're not sure what is loose when you wobble the wheel, put a good solid stand under the car and climb under so you can see what's moving when you move the wheel, you will soon see if it's the wheel bearing or ball joint. If you are giong to do this don't just trust the jack, you will need another stand as well.

[Moppitt]

There is any number of things that could be. I will say that you will definately be working in the LHF wheel area to find the problem. Im assuming its a sliding type caliper as you say its stock. The heat is my main worry, its coming from some kind of friction and brakes dragging will do that, also would explain the smell.

The first thing you are going to need to do is to get the car jacked up and on stands and take that wheel off. See if it rotates freely first though. I would first push the pads back in a bit (carefully) with a screwdriver (first check to make sure your brake fluid reservoir isnt too full and be sure it doesnt overflow) try and push the inboard pad in first as thats only the piston your trying to move there. Once there is some space (only need a couple of mm) between the pad and disc you should be able to move the caliper back and forth freely. If you could press the pad back but cant move the caliper then its the slides, if you couldnt press the pad back in then its something siezed on the caliper like pistons in to the bores.

Once you have pressed the pad back and if the caliper moves reasonably freely back and forth try and turn the wheel hub, if it drags or grinds or clunks or has free play then start thinking its bearings.

Of course it could be a myriade of different things like a pad worn way down and sitting cockeyed (crooked) in the mounts or something like that but you will only know by looking at it.

Hope that essay helps

[rustyP]

OK, Did some work on this..

When jacked up, the wheel didn't rotate well. It was going around, but was clearly scraping on something. I couldn't push the pads around while the caliper was on though.. couldn't get anything (Screwdriver) in there to wedge it.
So i undid the slides, pulled the caliper off.. it was damn tight!!
After pulling that off, the hub still wouldn't turn particularly well. Still scraping...
Then pulled the pads off front and back, and still scraping!
Then realised it was because without the wheel on, the disc was coming off-center and scraping on the caliper bracket... If i pushed it flat (like with the wheel on) then it would spin freely and smoothly
Would I be correct in assuming this means it's definately caliper problems?

With the pads out and caliper off, the slides for it would go in and out pretty easily... so they didn't seem seized.
I had to stick it all back on unfortunately (exam in a few hours, needa get to uni), but would I be correct in thinking the caliper must have seized?

Putting it all back together, the caliper was a bitch to squeeze onto the pads, but i eventually got it all good again.
Final testing, it may even be worse than before, with the wheel really quite hard to turn while jacked off the ground.

How does one fix a seized caliper? Is it just a matter of pumping it in and out a bit (with a clamp?) and oiling it so it doesn't get stuck again?

Also, is it likely to be related to discs that are too thin? ie Should i get new discs? The pads still have a bit of life in them. (a bit, not a lot, and seem to have worn evenly)

Thanks a lot for your help everyone!

[xman]

Sounds like the caliper is seized. You could try moving it with a clamp but oil is not such a good idea, the fluid on the inside should lubricate it enough. If this doesn't work you may need to invest in a caliper seal kit and give it a rebuild. the piston(s) can be poped out with compressed air, be carefull they can come out in a hurry... The pads could be worn unevenly due the seizing.

[TA-022]

certainly points to the caliper if there was no scraping without it.

[rustyP]

OK.
So it needs a rebuild... Is this a job I can probably handle?
If so, where do I get the parts for this, keeping in mind it's on an Aristo.

Or, does anyone know of a place I can have it done that won't charge thru the roof for it?

[barned01]

the calipers MAY be the same as a crown or soarer or early 2 piston version supra so if it matches to one of those, you should be able to get something, failing that toyota are always happy to ensure you have a light wallet

[rustyP]

Toyota quoted me $127 for full front left caliper rebuild kit from Japan.
I asked him to get one for a supra or such and he was a bit like "oh *grumble* we can't do that.. blah blah.. no guarantee it'll fit"... im like.. im SURE it will fit. he still grumbled about it.
From what I understand, the front brakes on these are samesame for the TT Soarers, the 32 V8 Soarers, the earlier JZA80 TT and all the NA JZA80's, as well as UCF20 Celsiors. Should be plenty of parts around!
Ended up getting me this quote from the rising sun for the aristo, which isn't too bad.

That said, the Brake shop around here that's supposed to be pretty good, theyve said "a caliper usually costs about $90ish".. so I mite just go with that for speed.

The Toyota guy gave me part #04479-30120
Can someone look it up on EPC and see if it's general or Aristo-specific? It should be the same for them all, but if it's specific, I may be able to track down a supra one or something that will still work and be in stock somewhere in this country.
Cheers.

[whatthe?]

Just to be a fly in the ointment, last time I had these exact same symptoms (especially the bit where it goes away when the car isnt in use for a while then comes back) it wasnt actually the caliper, but rather the master cylinder. Even the brake shop didnt diagnose it as such, and happily rebuilt my front calipers, which didnt do diddly for the problem.

Replaced the master in the pits at wakefield and all was good