Randomity
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Late Model brake troubles?
So here's the story.
decided to do the late model brake upgrade. bought the calipers, BMC, rebuild kits, new rotors, etc. Everything I'd need to do it properly.
conversion took a bit longer than expected and I finished this morning. rear rotors were delivered as wrong part, so i just left the old ones on til replacements arrive (no biggie, same part either way). went for a test drive and they seemed to rub a little. Looked this up and it didn't seem to be a problem. Apparently this happens with new pads, and should clear up fairly quickly.
Head out, about 2 k's up the road I notice that it's struggling to make power, and the brakes are holding more. Another 1k I stopped and all 4 wheels pretty much locked up there and then. Pads smoking and car stranded.
Anyone EVER experienced something like this? I'm totally stumped as to why they packed up so bad on me.
Current: 1992 SW20 MR2 GT-S 1997 BMW 318ti Rally car/Lemons car? Daily: 2017 Subaru WRX Tow Car: 2011 Ford Falcon FG XR6 Previous: 1999 AE101 Corolla 1986 AE82 Corolla 1991 SW20 MR2 Mongrel 1991 Nissan S13 Silvia 1982 Nissan 280ZX
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just_ace
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Re: Late Model brake troubles?
2013/10/19 13:50:39
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You used old the old smaller and thinner rotors with the newer calipers on the rear?
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Randomity
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Re: Late Model brake troubles?
2013/10/19 13:52:33
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They changed the Rotors on the rear? I wasn't aware of that. I was under the impression that the rear calipers, rotors and pads stayed the same from early to late.
So, yes
Current: 1992 SW20 MR2 GT-S 1997 BMW 318ti Rally car/Lemons car? Daily: 2017 Subaru WRX Tow Car: 2011 Ford Falcon FG XR6 Previous: 1999 AE101 Corolla 1986 AE82 Corolla 1991 SW20 MR2 Mongrel 1991 Nissan S13 Silvia 1982 Nissan 280ZX
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just_ace
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Re: Late Model brake troubles?
2013/10/19 13:58:45
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Yes, they changed both yhe front and rear. So that is most likely the problem. The pads probably arent wearing evenly for starters and the caliper is yo suit a 22mm disc not 16. Which means you may have pushed the piston out further than it is supposed to.
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Randomity
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Re: Late Model brake troubles?
2013/10/19 13:59:52
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would that also explain the fronts locking with the rears? all 4 were stuck when i stopped the car
Current: 1992 SW20 MR2 GT-S 1997 BMW 318ti Rally car/Lemons car? Daily: 2017 Subaru WRX Tow Car: 2011 Ford Falcon FG XR6 Previous: 1999 AE101 Corolla 1986 AE82 Corolla 1991 SW20 MR2 Mongrel 1991 Nissan S13 Silvia 1982 Nissan 280ZX
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Reddtarga
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Re: Late Model brake troubles?
2013/10/19 17:56:55
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Be also aware that later rotors are larger diameter as well as thicker both F/R, compared to early model rotors.
Early front rotors are 258 x 25 mm. Later ones are 275 X 30 mm
Early rears are 262 X 16 mm. Later rears are 280 X 22 mm
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Randomity
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Re: Late Model brake troubles?
2013/10/19 18:05:45
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Cheers for the info! Probably should have known that BEFORE attempting the conversion myself. The correct rear rotors will be arriving tuesday, at which point i'll be able to eliminate one issue, and maybe the problem will resolve itself with a fresh flush too!
Current: 1992 SW20 MR2 GT-S 1997 BMW 318ti Rally car/Lemons car? Daily: 2017 Subaru WRX Tow Car: 2011 Ford Falcon FG XR6 Previous: 1999 AE101 Corolla 1986 AE82 Corolla 1991 SW20 MR2 Mongrel 1991 Nissan S13 Silvia 1982 Nissan 280ZX
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Reddtarga
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Re: Late Model brake troubles?
2013/10/19 18:19:32
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Did you go for a later model booster as well? Toyota changed those as well and for your larger brakes to work properly you'll need that too.
One from a 92+ car would be ok but the best one to get would be from a 94+ car, but don't forget to also fit a vacuum check valve to the intake manifold.
Later boosters don't have one on the booster body like the early ones.
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track_mr2
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Re: Late Model brake troubles?
2013/10/20 07:54:06
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The rotor issue wont effect your brakes being permanently applied. Basically your car is always applying the brakes hence why they started smoking after 2km's then locked up after 3km's. Before even driving off after your rotor change just put the car in neutral and see if it even rolls on a slight hill or if you can push it on flat ground then work out if all 4 calipers are locking or just one. If all four are being applied it will most likely be the pushrod in the master cylinder being stuck too far forward.
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Randomity
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Re: Late Model brake troubles?
2013/10/20 13:51:55
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Well I won't be looking at it til Tuesday when the proper rear rotors arrive, but what could I do about the master cylinder if that is the case? Of all of suggestions I've had, that one seems most likely to me.
Current: 1992 SW20 MR2 GT-S 1997 BMW 318ti Rally car/Lemons car? Daily: 2017 Subaru WRX Tow Car: 2011 Ford Falcon FG XR6 Previous: 1999 AE101 Corolla 1986 AE82 Corolla 1991 SW20 MR2 Mongrel 1991 Nissan S13 Silvia 1982 Nissan 280ZX
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track_mr2
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Re: Late Model brake troubles?
2013/10/20 16:11:15
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I thought you said you just upgraded the master cylinder? Very hard to say without seeing the car. First you need to work out what is happening. Work out if your brakes are being partially applied then work out what is causing it.
You could have a seized caliper or could be master cylinder related. Jack up the car and spin each front wheel, see if they turn freely. Could be a simple as your handbrake not properly adjusted after your caliper swap and being constantly applied on the rears...
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Randomity
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Re: Late Model brake troubles?
2013/10/25 13:21:32
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Okay, here's the deal a few days later.
Correct rotors arrived.
Installed them, got the calipers on, re-flushed the fluid and took it for a quick drive round the block. Still rubbing lightly.
get home, jack car up, none of them are spinning freely. They turn with little effort on my part, but aren't free and you can hear the pad rubbing the rotor. At this point (aside from wasting just over half a Litre of high-temp fluid), I decided to just put the Gen 2 brakes back in. (This is proving harder than expected just because the rear calipers decided to push out and now i need to wind them back in too).
right now, the only thing i'm missing is the Gen 3 booster, functionality-wise. Everything else has been correctly lubed and installed.
At this point, i'm about ready to just give up and leave the Gen 2's on and cut my losses before i spend any more time and money...
Current: 1992 SW20 MR2 GT-S 1997 BMW 318ti Rally car/Lemons car? Daily: 2017 Subaru WRX Tow Car: 2011 Ford Falcon FG XR6 Previous: 1999 AE101 Corolla 1986 AE82 Corolla 1991 SW20 MR2 Mongrel 1991 Nissan S13 Silvia 1982 Nissan 280ZX
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Carmikey
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Re: Late Model brake troubles?
2013/10/25 13:36:30
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Hi Joe,
If I were you, & keeping in mind you need the car on the road like yesterday (im assuming), & track day is only 1wk away, I would be doing just as you have suggested.
Put the originals back on, then after track day, slowly start putting back on, eg, start with front rotors / calibers, test see how it goes, then go from there. Unfortunately it is a process of elimination.
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Randomity
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Re: Late Model brake troubles?
2013/10/25 13:40:17
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Yeah, at this point, that's what I decided to do.
Patience is wearing thin when stuff like the old calipers suddenly not fitting happens though
It'll be back on the road before work tomorrow, and if not, I may set it alight and watch it burn in my carport...
Current: 1992 SW20 MR2 GT-S 1997 BMW 318ti Rally car/Lemons car? Daily: 2017 Subaru WRX Tow Car: 2011 Ford Falcon FG XR6 Previous: 1999 AE101 Corolla 1986 AE82 Corolla 1991 SW20 MR2 Mongrel 1991 Nissan S13 Silvia 1982 Nissan 280ZX
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Carmikey
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Re: Late Model brake troubles?
2013/10/25 14:25:11
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If you do burn it... I have 2 for sale. Pick either one..
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