FireDemonSiC

Interesting thanks for the heads up.

TBH, I didn't do much reading into it after I saw the price of the fluid. If I had decided to go with the DOT5, I would have researched more into it.

MAC_87

iTrader: (3)

Fire, do you notice your brakes working
more effectively at higher speeds?
example:
going 70 MPH and coming to a stop - brakes work better than
going 40 MPH and coming to a stop

FireDemonSiC

Can't say I've noticed that. Are the RPMs about the same during both situations?

MAC_87

iTrader: (3)

no, my rpms run 2.3k @ 70mph, and about 1750 @ 40mph. different gears as well of course.

FireDemonSiC

I'm honestly not going to be of very much help here.

Since I have a manual valvebody in my 700R4, I make it second nature to downshift as I slow down so I won't accidentally leave from a stop in 4th gear and smoke the 3-4 clutches. Also helps prolong brake life, too!

With the added braking effect from the engine, I have much less observation over braking conditions than you do.

b_the_j

If your pedal is spongy it means you still have air in the system, its been my experience that its gets trapped in calipers and wheel cylinders. when you hit the pedal and it travels halfway to the floor you are compressing the air, the next time you apply the brakes the air compresses a little bit more resulting in a slightly firmer pedal. If you run your master cylinder reservoir too low it may intake some air. this will require bench bleeding. Sometimes you may get lucky and be able to push trapped air out of the master by bleeding at the hard lines without removing it from the car. When i put on a new caliper i like to fill it with fluid before attaching it to the flexible line. I then double check the fluid level in the master, replace the cap firmly, then push fluid out of the line to prebleed it... the goal here is to have minimal air in the line, and to have the air as close to the caliper as possible. Now attach the line with your banjo to the caliper as quickly as possible. now double check the master fluid level. Next, rest the caliper on the a-arm and slowly apply some pressure to the system. Be EXTREMELY carefull not to over apply and pop the pistons out of the caliper. this requires a lot of walking back and forth to check your progress. Start with a very short push (use your hand not your foot), then gauge the movement, then push then check, etc... until you have the piston extended half travel or so. The goal here is to push the remaining air from the line into the caliper. Now pick the caliper up and orient the banjo fitting exactly vertical. Loosen the banjo and depress the piston with your hand forcing the air out the fitting. If you cannot depress by hand you likley need a new caliper. (I sometimes can pop the piston out and clean it to restore function, this may be beyond your skill set, proceed as you see fit). Congratulations you have just preformed a one man bleed job. you may install the caliper and bleed it through the bleeder with help, to ensure 100% removal of air from the system. Keep in mind this procedure must be done from furthest to closest just as any other bleed procedure, and that all other brake components must be assembled completely while you bleed in this manner. If you suspect air in the master it must be bled 100% before starting. Always, ALWAYS, double, triple, quadruple check your master fluid level while bleeding to ensure it never comes close to going dry, because if it does you are back to square one and must start completely over no matter what you had accomplished.

Wheel cylinders on drums almost always bleed out 100% through normal bleeding, however it does help to tap on them while you are pushing fluid out to loosen up bubbles that may adhere to the walls of the cylinder.

The only other thing that may cause excessive pedal travel are improperly adjusted drums. One pump pushes the shoes out, the next applies them to the drum. Due to the design of the hydraulic system of most drums, (residual pressure valve) the shoes will remain extended for a short time, resulting in almost normal brake feel if brakes are applied frequently. The springs will gradually draw the shoes in compressing the wheel cylinders, resulting in the old double pump requirement that is remarkably similar to compressing air in the system.

I hope you all find this helpful, I have attempted to extend my knowledge thoroughly to this thread. Perhaps you can vote to have this write-up made a sticky on bleeding. My first Sticky!!! would be awesome!!. I am disabled veteran and was a mechanic on the AH-64A model for six years, and a UTI graduate.

P.S. Keep in mind that it is not necessary to force fluid violently form the system to accomplish bleeding. Nor is hard pumping, this only breaks up the air into smaller bubbles that are harder to remove from the system.

MAC_87

iTrader: (3)

Damn thats a lot of info, thanks b!
hopefully air in the lines really is the issue, however now that i think about it i think i may have a leak in the lines somewhere; every time i bleed my brakes, theyre hella better, but then a few days later theyre mush again. is there any way to test the system for a leak? i see no dripping/seeping of break fluid but that doesnt mean there isnt an air leak somewhere, right?...

MAC_87

iTrader: (3)

btw b, i love the 4th gen wheels on the third.

krauser

1st thing you need to do is isolate the problem. Do this by clamping off the brake hoses one at a time being carfull not damage the hose.
Clamp off the rear if the pedal is hard & high your problem is in the rear braking system. If nothing changes go to left front followed by right front. if nothing changes the problen is air in the marter cyl/ABS module (if equipped)

Colemaro

Ihave the same problem, that and the unreliable electronics in this car. My solution is to parts this out and give some one else a head ache, LOL.

FireDemonSiC

LOL!

MAC_87

iTrader: (3)

with what device/tool should i clamp it with? would putting cloth around the hose + using vice grips work?...

FireDemonSiC

I personally wouldn't use vice grips although if they are set to clamp too tight I don't see what harm it would do.

I would try spring loaded clamps from lowes or home depot. don't get the ones with monster clamping force but enough to pinch the hose shut. I myself am not going to risk this procedure since I am running braided steel lines but it was a very good write-up none-the-less. I actually thought about air being trapped in the calipers kind of the same way you have to bench bleed the master.

MAC_87

iTrader: (3)

you have metal braided lines all the way to the calipers/drums
on all 4 sides?

FireDemonSiC

Braided hoses. There's no reason to replace the body hard lines unless they're pinched/rotted.

MAC_87

iTrader: (3)

oh i see :P

krauser

I'm sorry I thought you were talking rear drum not 4wheel disc...ok if your running stock rear calipers with built in rear parking brakes (parking brake built into calipers) what I think is happening is the screw that adjusts the rear brakes is sticking inside the caliper piston. How big of a gap do you have between the inboard pad and the rotor? The pad should have around 1/32 inch gap. try this, remove the rear nut that holds the PB lever and the lever from the caliper. Now take a 9/16 wernch and turn the stud sticking out of the caliper toward the front of vehicle the stud should lock up the rear wheel. After the wheel locks up turn the stud back to the rear of the and reinstall the PB lever. If pads are worn you may have to have a helper apply the brakes while you turn the wrench. Be carefull sometimes the seal will fail and start leaking brake fluid with the PB lever off...

krauser

Oh one other thing... Are you sure that you dont have the caliper from the right side on the left side and Vic versa? A quick check is to be sure the bleeder screws are on the top of the caliper not the bottom.

MAC_87

iTrader: (3)

calipers are fine in back, both bleeder screws are on top, and are new/rebuilt
calipers. parking brake cables are new as well.
have had the same issue Before the calipers + cables were replaced as i do now, with them replaced.

t-top havoc

iTrader: (3)

Lol!!
Been called worse!! Lol!!!

So I'll ask a dumb Q---
Is your pedal bent??

sailtexas186548

iTrader: (2)

so have either of you guys with this problem pulled your master out and bench bled it? It's impossible to bleed all of the air out of it on the car unless you leave the front wheels on the ground and jack the rear of the car up until the master is sitting level, which is why it's just as easy to pull it out and bleed it by holding it horizontal in a vice (clamp to the mounting flange NOT the body)

MAC_87

iTrader: (3)

not that i'm aware.

MAC_87

iTrader: (3)

nah i havent tried this..

b_the_j

I recall a few years ago I had a U-joint fail at 130 or so (CHEAP A$$ advance ap CRAP). Extreme vibration destroyed my pinion bearing and launched one of my blackout covers onto the highway. (I recovered it about 4 hrs later after i realized it was gone, only minor scratches amazingly!!!) after replacing the axle and attempting to bleed the rear brakes I could get no fluid to pass through the system. I could only get dribbles out of the front. I ended up having to replace the master cylinder and the the distribution block with the imbalance switch as well. I have no idea why this went down at all...I disassembled both of them and found no sign of damage or unreasonable amount of debris inside.

BTW i no longer have the 4th gen wheels
.

sailtexas186548

iTrader: (2)

you should, if the master has air in it your going to have a spongy pedal...

84Camarodriver

my brakes fluid in my 84 is pitch black is this a bad sign?

sailtexas186548

iTrader: (2)

well its not good, it could mean a few things:

1. your fluid could be old and need to be changed

2. you could have a brake line really close to a heat source (exhaust) that is getting your fluid too hot and casuing it to break down and turn black

3. the seals in your master cylinder could be breaking down turnin your fluid black

I would flush the whole brakes system and see if the fluid turns black again quickly, if it does you know you have a problem somewhere

coreyc1210

What about the chance of the push rod being out of adjustment, if its set too short then yes your going to have your pedal almost to the floor, but idk just a thought, heres a link on adjusting it, page 12 http://www.autoshop101.com/forms/brake05.pdf

84Camarodriver

Thanks for the fast reply!, is there a brake fluid that is more superior then the next?, or are they all the same?,

naf

iTrader: (7)

There's no adjustment on our brake pushrod.

You'll be fine with DOT 3/4 brake fluid. If it's black, flush it good. I'd first loosen MC from the booster and check behind it for evidence of it leaking. Replace it if leaking.

DOT 5 fluid 'could' be used, but you'd have to get rid of ALL of the residual fluid that's in there now because it won't mix.

manualbrakes.com

Your step bore master cylinder (24mm secondary bore & 31.6mm [or 36mm] primary bore) is more than likely the problem. You either have air in the step bore master cylinder or the built in step bore bypass valve in the master cylinder is not functioning like it should.

A step bore master cylinder is used with low drag / quick take up calipers.

http://www.mpbrakes.com/uploads/documents/lowdrag.pdf

These calipers came stock on all third gen camaros / firebirds with the 10.5” rotors. These calipers where also used on 1981 to 1988 g-body cars (rwd monte carlo, rwd cutlass, rwd grand prix, etc) and 1982 on s10 pick up and blazers. Low drag / quick take up calipers require more volume of fluid initially to function properly. This is where a step bore master cylinders is needed. Its larger primary bore will feed the calipers with the required volume of fluid. A built in by pass valve, in the master cylinder, is used to transition to the smaller secondary bore once a predetermined PSI is reached (around 100 PSI).

Just remember this (in general):
Big bore master cylinder (in general, greater than 1” bore) = More Fluid Volume / Low Fluid Pressure
Small bore master cylinder (in general, less than 1” bore) = Less Fluid Volume / High Fluid Pressure

Low drag / quick take up calipers need both a large bore and a small bore master cylinder. That is why GM designed the step bore master cylinder to give the calipers both volume and pressure.

Here are some links on how to properly bleed a step bore master cylinder

http://www.dormanproducts.com/docume...Bore042005.pdf

http://www.performanceonline.com/blo...ench-bleeding/

http://www.raybestoschassis.com/wps/...df?MOD=AJPERES


In a rebuilt step bore master cylinder, the bypass valve may or may not have been replaced. If the bypass valve is bad, or not working correctly, it could cause a spongy pedal also.

91L98Z28

great info on the step bore master.

I have OFTEN wondered if the step bore is a contribution to the general sucky brakes that a thirdgen has.

I've noticed that if I very gradually apply the brakes, they seem to "catch" relatively high, and have pretty decent feel. Not supercar by any means, but once they catch I can clamp down on the pedal pretty hard and they seem to work about as well as you can expect of 10.5".

But if you STOMP the brakes, the pedal sinks quite a bit and the brakes feel like felt pads on glass rotors, and there is hardly no "bite". Possibly the bypass valve opening up and the master working on the smaller bore right from the start, necessitating a LOT more displacement to get enough fluid into the calipers to work??

manualbrakes.com

To me, that theory is sound and I could see how the brake pedal would sink if the pedal was stomped on. The bypass valve in the master cylinder would experiance a spike in fluid pressure and the bypass valve would open prematurely. If the bypass valve opened prematurely, the volume of fluid wouldn't be enough to quickly fill the low drag / quick take up caliper. You would get a longer pedal.

That being said, if a normal (NON low drag / NON quick take up) caliper was used, you wouldn't experience a sinking pedal if the pedal was stomped even when using a step bore master cylinder. The bypass valve would open quicker bypassing the fluid anyway because there is not need for the increased volume of fluid in with normal calipers.

Orr89RocZ

iTrader: (20)

subscribing...had issues with the stock brakes from day 1 and now with C5 fronts and LS1 rears, I still have a spongy pedal and bled the brakes many times. Havent bench bled the master but I'll have to try that next. Just doesnt stop as hard as it should. My 99 TA stops great and its a heavier car with smaller brakes.

My booster also doesnt hold vacuum over night but that would give a hard pedal. It holds for a few hrs and then I get little to no vacuum left for the pedal.

manualbrakes.com

In my opinion, if you are running a stock master cylinder with the C5 front brakes, you need to upgrade to a strait bore master cylinder. The bypass valve and the bleeding proceedures in the step bore master cylinder is two more variables to deal with when trying to diagnose brake problems.

C5 Corvettes came with a 1" bore master cylinder from the factory and so did the 2002 Camaros. It would take some research to see if the master will bolt up correctly with your vacuum booster, but the 2002 Camaro master cylinder has the same brake line outlet sizes as the third gen Camaros. The outlets also come out on the passenger side of the master cylinder, just like the third gens.

Orr89RocZ

iTrader: (20)

i've seen guys use 4th gen masters on 3rd gen boosters and even some 4th gen boosters/masters combos. They will bolt in.

Now it was my understanding the C5 vette used the same caliper as the fbody cars, the only difference was the way it was made. Fbody has a weaker cast design while the vettes had something abit different that could withstand the heat for track use? More resistant to cracking? I actually have the C5 Z06 versions which are just nicely powdercoated red.

i will look for a 2002 master and look into replacing the booster as well. This is the first time I heard of the step bore cylinder vs straight bore.

I knew the 4th gens had a different bore size but didnt know anything else was different.

sailtexas186548

iTrader: (2)

I have the same setup, had a spongy pedal, new master & bench bled it, problem solved

manualbrakes.com

What master cylinder are you using?

A new, not rebuilt, master cylinder your your year camaro?

Dave

sailtexas186548

iTrader: (2)

"1991 z28" rebuilt master cylinder, the braking is great

Orr89RocZ

iTrader: (20)

Hmm i will have to try something new and bench bled Stopping from 140 gets alittle scary

FireDemonSiC

Does anyone know if the direct bolt in SSBC dual piston calipers for our 10.5" rotors are a low drag setup? It would be interesting to see the actual difference in performance they offered, that is if the PRICE was justifiable

manualbrakes.com

The calipers are more than likely not low drag. Low drag calipers are machined differently for the seal and I doubt they would modify these calipers different from the rest of the calipers that they offered.

Here is a link to explain the low drag calipers.

http://www.mpbrakes.com/uploads/documents/lowdrag.pdf

Do you have a link to the SSBC calipers?

FireDemonSiC

The model of the calipers is A181.

Everyone is saying they would be a DOWNGRADE because while they have more equal clamping force across the pad area they have less piston to p[ad contact area than the stock calipers.

HOWEVER, I do not see a single person who has installed these and checked for themselves. It is all in theory ATM.

manualbrakes.com

I was going to make the agument for the SSBC calipers, but I can't. The only real benifit is that they have twin pistons, but they are small at 38mm (1.496) each. Lets compare.

SSBC caliper w/ 1.496" dual piston bore = total area of 3.51" - A181
Stock replacement caliper w/ 2.50" single piston bore = area of 4.91" - low drag, rebuilt
Aftermarket caliper w/ 2.50" single piston bore = area of 4.91" - non low drag, new
Aftermarket caliper w/ 2.75" single piston bore = area of 5.94" - non low drag, new

b1k1w1

if you have a leak look for wet spots. If some one is pumping it will help you to find leak, use bright lite. Do not bleed from banjo that's what bleeders are for. And dot5 is not for safe use even with everything replaced!!!! Only dot 4or3. If you are bleeding keep drums on and disc brakes together. There is nothing wrong with step bore. But I had this problem before turned out I put check valve in backwords and pedal went straight to the floor. It would work for a sec and then go out again. There's a lot it could be, sometimes it takes someone with experience to look at it. I even have to suck it up and ask the led tech sometimes. That's how we learn the safe way. Brakes are the last thing you want to mess up on. If you can't stop the car, something or someone will. And don't forget a built engine can cause a soft pedal do to lack of vacuum. If any thing was brought up sorry I missed it have kids have to read quick. there are books that explain what parts do and how they affect car including ase books check them out might help.

RBob

iTrader: (1)

The stock 3rd gen cast iron front caliper has a 2.5" bore for 4.9 sq/in of area.

The piston is stepped in diameter, so unless it is removed from the caliper the measurement is incorrect.

RBob.

manualbrakes.com

Thanks RBob, I rewrote my above statement. 2.38" is the caliper piston diameter (measured). 2.50" is the caliper bore diameter. It has the same area as an aftermarket (U.S. Brake / Afco) caliper.

91L98Z28

Are these any particular/specific aftermarket calipers, do they bolt on in replacement of the stock caliper?

Switching to a 4th gen straight bore master and 2.75" single piston non-low-drag front calipers might be a decent little budget upgrade?

manualbrakes.com

The calipers in the links above are produced by U.S. Brake and/or Afco Racing. They are brand new non-low drag (normal) calipers. If you have stock 10.5" rotors on the front of your Camaro/Firebird, these will bolt on. They can also be used on 1982 and up S-10 trucks/SUVs, Thirdgen Camaro/Firebirds, and 1978 to 1987(8) G-body (Malibu, Monte Carlo, Regal, Cutlass, El Camino, etc.) vehicles which also come with the 10.5" rotors.

Your step bore master cylinder will still work with these calipers, but it has two issues may makes it more difficult to diagnose brake problems. It is more difficult to bench bleed a step bore master cylinder. The bypass valve in the step bore master cylinder may be good or may be bad. There is no way to check it, no way to replace it, and there is not way to know how a bad valve will affect your braking (that I know of).

RBob

iTrader: (1)

IMHO, the best upgrade while retaining the stock 10.5" rotor is better pads. With the small rotor more caliper doesn't do a lot. The rotor can only take so much before it heats up and the brakes fade (and badly at that).

RBob.