a 'stock' brake master upgrade?

[300ZXTC]

my 85 GTS brake master has a leak. (bubbles can be seen in the res when cleaning the bay with shop air) And wont bleed correctly.

I ordered a new master from Oreillies after telling them- 85, Corolla, GTS, hatchback.
they gave me this 7/8 unit-

the one in my car is more like this other option with the two hard lines atop.-


that they say is for a coupe. WTF is going on.

also from what ive read on the older boards, the OE cyl is 5/8? this one they gave me is 7/8.
im currently away from my car and wont be able to eye this one up to it in person until tomm afternoon.

As a backup, ive also ordered the cylinder that -looks- right so i can exchange if need be.

-Has anyone used this Master cyl unit with the res that has two ports on the bottom?

-Is it feasable to bend my hardline to match the side port of this bigger unit?

[kiosk]

Bore is 13/16"

A bit of a protip when looking for hardware parts like this

If they ask you what you have, choose RWD coupe. Even if you have a hatchback.

[Engmus]

Word to the wise, none of the parts suppliers like advanced, autozone, Oreillies, Rockauto etc get parts right.

Rockauto sold me a alternator for my 86 hatch and it was for a FWD model (They swore it was a RWD model part), they REFUSED to issue a refund\RMA until I sent them photographs with a fucking measuring tape next to the old\new unit showing that the bolt holes were severely off from the new to old unit.

I ended up going through my local dealership for that part...

In any case I recommend http://www.toyomotorparts.com/ or any other website where you can enter your VIN to get parts, it really helps with part accuracy.

[300ZXTC]

noted thanks.

i eventually got the 'coupe' 13/16 unit and got it in.

IT of course wasnt w/o drama. even after using WD-40s new penetant, i snapped the flare wrench on the brake hardline and started to strip it with a regular wrench.

ended up removing it from the other end and taking the old unit out that way. then removing the reservoir and torching the nut to get the line off.

**QUESTION, when i was bench bleeding.. fluid was only moving from the res to the fitting closest to it. Though both fittings had tubing running back to the res.. the further line had no fluid moving thru it.
Is that side supposed to stay dry until hooked up to the vehicle again?

[Jeonsah]

You should have fluid moving through all parts of the master cylinder.

[300ZXTC]

yes, something is amiss. i was wondering if it was somehow the booster.

For normal stopping street driving, it seems to work fine. when i have to really stop fast, i have to push unusually hard. the wheels will eventually lockup.

What could be the cause of the fluid not moving thru the fwd fitting?

[assassin10000]

Need to shake/bleed it at a downward angle so the bubble in the line goes back to the reservoir. Once the front feed line has fluid to the front bleed like normal.

Andrew

[300ZXTC]

hmmm got it. ill try again. brakes feel like crap.
And for some reason this cylinder rusted bad VERY fast. Ill have to treat/paint it i guess while i re-bleed.

[MisterJerk]

RPM(classified, shops section) has them at a decent price, also made by Aisin(OE manufacturer)
I got all my hydraulic stuff, brake master, clutch master and slave, through them.

Before I go to any local parts place i go to the Shops section and support the sponsors of this site. Local spots, like autozone, don't have shiz, and 9 times out of 10 its a fwd part.

http://club4ag.com/forums/viewtopic.php?f=22&t=1957

1 Aisin Brake Master Cylinder AE86 Made in Japan

$89.00 Free Shipping in U.S.A

[allencr]

Fluid should flow freely out of the port/s from the reservoir.
If it isn't, something is wrong like smegma/assembly grease blocking a passage or the booster's pushrod is adjusted too long. Also the MC could be assembled wrong or have wrong internals.

If it's smegma, just pumping your palm on top should push through it.
Push rod adjustment can be trial-and-error, or removing the reservior to GENTLY insert a wire probe into the port to adjust the push-rod preload right.

[Red]

Everyone, including the dealers, has always gotten the GT-S mixed up since Day One.

GT-S? Oh, that's a Celica, right? Uh, no, Corolla. Oh, FWD? Uh, no, RWD. Diesel? Uh, no, 1.6L DOHC RWD.

And if you think that's bad, try ordering a muffler and tailpipe, you'll get generic 4AC Corolla parts from all the aftermarket sources, unless you're ordering "performance" parts.

When I had mine replaced (shaft was weeping ever so little, but I didn't want to wait for that to get worse) I had them replace it with an 86-87 part, which someone had posted as being an improved version that would bolt right into the 85. It did, it does, works just fine. I'm sure a "different" bore and stroke on the cylinder MIGHT be just as good, but brakes are something I don't want to screw around with. If the aftermarket part looks different in any significant way, just give it back. Life is too short to bother with that crap.

[allencr]

(shaft was weeping ever so little, but I didn't want to wait for that to get worse)

Please??

[Red]

The shaft which penetrates the firewall and connects down to the brake pedal linkage is o-ring sealed. That o-ring apparently was wearing out and while brake fluid wasn't dripping inside on my feet, if I ran my fingers over the rod they came away wet with fluid.

So, it was weeping, not dripping, and that's a sign of failure to come. While I had some other work being done I said "take fixee" and had the entire master changed out at the same time. And as long as they were changing it, I told them to use the later design. Price was the same either way, or within a buck or two of being the same.

[oldeskewltoy]

Be careful bleeding the brakes..... DON'T bottom out the pedal!!!

Either tape a 4x4 under it, or something but do not bottom out the brake pedal. Why? A seal can get slightly nicked, the pedal will allow you to bleed and it will get hard... but as soon as you start the car, and then hit the brake pedal, the booster vacuum draws in air and all of a sudden the pedal gets soft. You bleed, it feels fine, you start the car and it fails...

[300ZXTC]

Be careful bleeding the brakes..... DON'T bottom out the pedal!!!

Either tape a 4x4 under it, or something but do not bottom out the brake pedal. Why? A seal can get slightly nicked, the pedal will allow you to bleed and it will get hard... but as soon as you start the car, and then hit the brake pedal, the booster vacuum draws in air and all of a sudden the pedal gets soft. You bleed, it feels fine, you start the car and it fails...

ufff. thanks. but that sure ISNT what i did. i bled it bottoming of course. But the way you describe.. is not the pedal feeling i have. (i still havnt touched it since the last post as i am deployed till Nov) the pedal and braking feel ok for normal street driving. when i have to brake hard and fast, it seems the pedal gets unusually stiff half to 3/4 the way down and it takes ALOT of pressure to stop quick and/or lock the wheels.

auuugh i probably need to try another cyl and get an aisin

[NateTheRipper]

I am going to try this as I am having issues with my brakes after overhaul. will get pressure until car is started then no brakes. Replaced MC(bench bled), Brake Booster, rotors pads everything.