Brake problem

keith · Post by **keith** » Tue Mar 27, 2007 6:14 am

The Tercel is getting harder to stop in its old age. Over the last couple of years I have replaced just about everything. The rears got new shoes, drums, wheel cylinders, hardware and hoses less than a year ago. I just put on new front pads and rotors. The pads are Autozone ceramic pads, not the racing only pads, the street pads. I rebuilt both calipers, then replaced the drivers side with a reman because I found the piston rusted pretty badly. The caliper bushings (pins) are clean and freshly lubed and I put on new rubber seals. I also replaced the master cylinder with a reman. Both front hoses were replaced a couple of years ago, I replaced the drives side again when I bought the reman caliper.

I thought the brake booster might be going bad, but it passes all tests according to the FSM. I think the problem may be related to the Brake pressure metering valve, aka, the proportioning block. The passenger side front wheel will lock up under hard braking, the drivers side will not. It did not before doing the front brakes either. All four front pads were worn about the same though and it does not pull to either side under normal or hard braking. The rears never lock up either.

The last time I did the fronts, I noticed that the passenger front wheel tended to lock up, but the car stopped much shorter then than now.

Bleeding operations are normal, I get good flow at all four wheels while bleeding so I don't think there is any blockage anywhere in the system. But the passenger side front wheel is the only wheel that does not go through this block. I've had good luck with ceramic pads before, but could they be a problem on this car? The last pads were carbon fiber pads and they didn't seem to work any better.

Normal braking seems to be ok, its just that emergency braking is taking longer than it used to. Anyone else experience this? Does everyone else's Tercels only lock up one wheel? Should I go back to semi-metalic pads?

Typrus · Post by **Typrus** » Tue Mar 27, 2007 11:01 am

I'm capable of locking all 4 if I really ask it to and stand u on it.
My pass front has always been first to lock up. I think that is because it bypasses the metering valve. It gets direct pressure whereas the others are metered and under hard braking, proportioned.

The proportioning valve part of it keeps the rears from locking under heavy braking (supposedly) so I'd imagine yours is working fine. The Metering valve makes it such that the rear shoes make contact with the drum before the front brakes engage. So I'd guess that unless there is a wacky blockage, yours might be just fine.

Is your reman master adjusted properly? Have you checked your pedal freeplay? I put a reman in my car and it was way loose. Adjusted it and its fine. I put one in my sis' 81 Corolla Tercel and it wouldn't let the brakes back off (too tight) so I even had to space it out away from the booster to get it right.

I use Semi-Metallics. I'd recommend them to anyone.

AutoZone brakes are not good brakes.
Advance/Checker carries good brakes, and bad brakes. They carry Bendix, which are some of the best out there, as well as cheaper brands. One brand, Wearever, can be both. Their Wearever standards and Silvers are pretty iffy. The Wearever Gold's are great though. I have them on my car and thy are less than halfway worn over the last 25k miles of my driving style. To give you an idea of what that means, my rotors are a solid chunk of bluish-black. Yeah. lol.

I think the best idea would be to upgrade. What was it that people were swapping to? MR2 or was it later Tercel/Paseo brakes? Same bolt pattern, just slightly larger diameter (maybe 1 or 2 mm) and vented. You need the appropriate calipers, which apparently bolt up, you just need to fit the banjo-style hose.

I believe that shogun was the first to do this mod?

I personally want to do that mod, along with fitting an AE86 Kouki rear end with disc brakes. All-wheel discs.

Mac · Post by **Mac** » Tue Mar 27, 2007 10:27 pm

same here with RF locking up first.

if the pedal feels kinda crappy, I'd lube up the rear shoes against the backing plate and ajust them manually, i find the automatic ajusters in the rear rareley work well on any vehichle.

to ajust rear brakes i'll put the wheel up in the air, give the wheel a spin, and then ajust them with a brake tool untill i can get a half spin out of the wheel before it stops, i find that works about perfectly.

takza · Post by **takza** » Wed Mar 28, 2007 3:58 am

My car stops pretty well...wouldn't want to get behind me when I decide to stop. Can't ever remember locking them up on solid pavement....might be the Kumhos.

AdvanceAP Gold pads in front.

My guess would be the master cylinder...I've noticed with the Japanese ones...that they are difficult to bleed.

One thing I do when I have brake problems is to find a back road and panic stop from 55 a few times...this can work out some kinks. But you have to stop under a shade tree for this to work.

keith · Post by **keith** » Wed Mar 28, 2007 7:43 pm

Its got a reman master cylinder. I live on one of those back roads and I have a shade tree, a whole bunch of them in fact. It has been getting harder to stop before the new master cylinder, I replaced the master cylinder because it failed while I was bleeding the brakes after putting on the new pads and rebuilding the calipers.

This has been a progressive problem over the last couple of years. It feels like not all the brakes are doing their job or the brakes just aren't big enough, but they used to work fine. There aren't many parts left to replace.

Normal stopping is ok, it doesn't require any extra effort. It feels like any other car, its sudden braking that worries me, it takes almost 150 feet to stop from 60 mph. It used to stop in about 130. On a second stop from 60, it won't lock up and takes nearly 200 feet to stop.

Post by **ARCHINSTL** » Wed Mar 28, 2007 10:16 pm

Well - here are the stopping distances from road tests when the car was new:
1983 R & T____60 mph to 0 - - 154 feet
_____________80 mph to 0 - - 279 feet
1983 C and D__70 mph to 0 - - 199 feet
1985 C and D__70 mph to 0 - - 205 feet

These results seem pretty consistent - and these guys were not known for babying their test vehicles (at least not moderately-priced cars). Your prior result of 130 feet from 60 is pretty surprising.
Tom M.

Typrus · Post by **Typrus** » Thu Mar 29, 2007 12:51 am

Its those "ceramics" you have. Autozone "ceramics" are such a low level of ceramic they don't remotely deserve the title. Plus, any ceramic has an organic base to it, so it doesn't repeat stop very well at all.
Semi-Mets will help a lot. As my brakes are evidence of, the pads will keep grabbing long after the rotor is hot enough to turn so blue its almost black.

I take longer than I'd like to stop. And the effort is more than I remember it being when I first started driving the car.

Vacuum-bleeders work wonders.

Why do master cylinders love to fail right after brake jobs?

What brake fluid you using and how often do you flush it?

keith · Post by **keith** » Thu Mar 29, 2007 4:32 am

I used Valvoline Synthetic Dot 3/4 this time. In the past, I have always used Dot 3. My son has always been hard on brakes and I flush the system everytime I change anything in them. You just can't flush too often.

As for me, I have 130k on my Saturn and still the original brakes. Don't believe in using them. Nobody ever got into the winners circle by using their brakes.

takza · Post by **takza** » Thu Mar 29, 2007 5:32 am

What you describe sounds similar to another Japanese car I had...replaced front hoses...calipers...rear calipers....MC was replaced a while back. Still had this problem of pulling slightly.

Possible that the block just distributes...and the proportioning is in the MC?

Might try the Advance Golds...they make no noise...stop good. Could be the pads have transferred material to the rotors?

keith · Post by **keith** » Thu Mar 29, 2007 6:07 pm

takza, I don't think the proportioning is done in the MC. It used to be done that way in the 60's when dual master cylinders and disc brakes first came on the scene. The tercel uses a system first produced by Saab where each cylinder of the MC feeds one front and the opposite rear brake.

There is a splitter just below the MC that sends fluid from one cylinder to the pass front and to the metering valve where it goes to the driver rear. The other line goes to the metering valve where a line immediately above the input goes to the driver front, the rest goes thru the metering block to the pass rear.

The FSM doesn't have a diagram of the hydraulic system or even show or mention the metering block. Apparently they must be pretty trouble free.

Typrus · Post by **Typrus** » Thu Mar 29, 2007 7:13 pm

The 2nd block is a metering/proportioning block. MC just makes pressure.

I am only recently getting a very very subtle squeek out of my brakes. I think it'll pass, probably just some goo somewhere.

Amen to the flushes. Especially at the tail end. Wheel cylinders don't seal water out too well.

shogun · Post by **shogun** » Mon Apr 02, 2007 1:23 pm

do as i did, motul rbf on the liquid side, tercel 91 hubs discs and calipers, and a good set of brake pads, but better braking depends on the quality of the tires mostly

keith · Post by **keith** » Mon Apr 02, 2007 6:49 pm

motul rbf on the liquid side

huh? The tires are not the problem, if they were, I could lock them up.

shogun · Post by **shogun** » Mon Apr 02, 2007 7:43 pm

give a little adjustment to the rear drums, it could be that the rear brakes are not doing a lot of work

takza · Post by **takza** » Tue Apr 03, 2007 5:41 am

I'd say pull the pads and rotors and lightly hand sand the rotors evenly both sides...flat sand the pad surfaces...and see if this helps.

Maybe you have a set of non matching rotors from different lots?

http://www.stoptech.com/tech_info/wp_wa ... disk.shtml