Late Model brake troubles?

Re: Late Model brake troubles? (Reddtarga)

Sun, 27 Oct 2013 18:24:16 GMT

"Gen 2 BMC on, still rubbing"
So do you now have the original 7/8 M/C with the original booster you had before the conversion?

I had previously wondered if push rod clearance between the booster and the M/C may have been your problem, but if you now have the original booster/MC combo that presumably worked ok with your old brakes before you started the swap then the problem is probably not that.
(When fitting different M/C's or boosters you are supposed to check the push rod clearance between the booster and the M/C. The service manual describes how to check and adjust that, along with the brake pedal play).

Re: Late Model brake troubles? (Randomity)

Sat, 26 Oct 2013 13:11:36 GMT

Update on that: Gen 2 BMC on, still rubbing. I'm totally lost now. There's clearly air in my ABS reservoir again (which i'll sort out), but I'm completely stumped regarding the rub i'm getting...

Re: Late Model brake troubles? (Randomity)

Sat, 26 Oct 2013 11:51:19 GMT

^^ you know, given it's the only thing I haven't changed back, that would have to be it.
I've bought some (more) fluid, just cheap stuff this time. I'll change it back over, and hopefully problem solved!

I merely assumed that a BMC being sold in good working order would be in good working order... That said, how do you check without actually installing it and finding out it doesn't work?

#brakenoob

Re: Late Model brake troubles? (track_mr2)

Sat, 26 Oct 2013 10:05:58 GMT

If all four brakes are being applied its got to be master cylinder related. Your plunger in the master cylinder might not be moving back far enough. Because your fitting new pads and all I assume with this upgrade, the pads will be really thick and because your old set up probably has worn pads (thinner) it pushes back far enough before getting stuck to not cause them to keep rubbing.

Re: Late Model brake troubles? (Randomity)

Fri, 25 Oct 2013 15:16:40 GMT

They don't look too bad on, actually... Didn't work out particularly nice on mine. Being grey, it looks too monochromatic

UPDATE: second test drive, got to some speed (about 80 or so), front rotors were pretty bloody hot after that, rears still have minimal heat, but it's there

Re: Late Model brake troubles? (Carmikey)

Fri, 25 Oct 2013 15:12:45 GMT

^^yeah wouldn't it.. heres how she looks with ya old wheels on it.

Re: Late Model brake troubles? (Randomity)

Fri, 25 Oct 2013 15:02:48 GMT

I'll keep that in mind
Care for a swap? That green one was good fun to drive, I'll give you that :P
I'll take my running gear out and put it in that thing! It'd be a mad street/track/touge car!

Re: Late Model brake troubles? (Carmikey)

Fri, 25 Oct 2013 14:25:11 GMT

If you do burn it... I have 2 for sale. Pick either one..

Re: Late Model brake troubles? (Randomity)

Fri, 25 Oct 2013 13:40:17 GMT

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...

Re: Late Model brake troubles? (Carmikey)

Fri, 25 Oct 2013 13:36:30 GMT

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.

Re: Late Model brake troubles? (Randomity)

Fri, 25 Oct 2013 13:21:32 GMT

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...

Re: Late Model brake troubles? (track_mr2)

Sun, 20 Oct 2013 16:11:15 GMT

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...

Re: Late Model brake troubles? (Randomity)

Sun, 20 Oct 2013 13:51:55 GMT

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.

Re: Late Model brake troubles? (track_mr2)

Sun, 20 Oct 2013 07:54:06 GMT

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.

Re: Late Model brake troubles? (Reddtarga)

Sat, 19 Oct 2013 18:19:32 GMT

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.