89bonezz

FireDemonSiC

I'm updating this thread to let everyone know that today I finally swapped the master cylinder out with the one from the totaled RS.

I bench bled the "new" master cylinder, put it on the car and gravity bled all the lines starting with the right rear and ending with the left front. I also pulled the distribution block and douched it out with carb cleaner.

Considerable difference in braking feel. As with thirdgen brake systems it still requires somewhat of a heavy foot but there is far less pedal travel now before the brakes come on and I was able to lock them about 5 times. 35mph stomping the brakes locked up the fronts and caused the car to understeer.

I'd say it wouldn't hurt to change my booster out as well but I think this fixed the majority of my problem.

Good luck to everyone else with this issue.

BlueZee28

iTrader: (30)

I've got the same spongy feeling in my brakes and I'm nearly certain it's because the fluid has been contaminated with being exposed to air. The lid on the reservoir wasn't secured and I drove it unknowingly for a couple weeks, and now the brakes suck.

naf

iTrader: (7)

A reman master is ridiculously inexpensive. Swap it, blow out your lines and fill it with new, shiny fluid.

If you haven't replaced your front calipers, they're like $13 each at AZ or one of the others. Replace your hoses too if their age is unknown. With new pads (I currently like the Wagner Thermoquiet) all of this can be done for around $100, maybe a hair more. You can even 'rent' the vacuum brake bleeder from AZ.

FireDemonSiC

There is no way he can do all that for around $100. Maybe prices are different where you are but here the thermoquiet pads and master cylinder alone will put him within $10 of the $100 mark. That's not taking into consideration whether or not he needs new shoes.

Cheap rubber hoses I'd expect to be around $10 a pop, but I chose to go with Russell braided lines. Add another $8 for a big bottle of brake fluid (You can get away with about $5 but I like the Valvoline synthetic. I have a phobia against the cheap stuff)

You were right on with the calipers. Expect about $13 give or take with the core.

BlueZee28

iTrader: (30)

Not with LS1 brakes these are slightly more expensive haha

FireDemonSiC

I believe he has us there.

naf

iTrader: (7)

I can get the reman MC for $24.99 (AZ)
brake hoses for $10.99 each (AZ)
ThermoQuiet pads (ceramic) for $31.81 (Advance)
Calipers $13.99 (AZ)

Total comes to $106 and some change. Then add fluid (last time I did a complete brake flush I used two bottles).

There does seem to be a bit of regional discrepancy in prices from the chain parts stores (AZ/Advance/Etc.). Guess I'm in one of the lower price regions.

Yay me.

resop27

iTrader: (8)

I'm having this same problem, cant find any leaks I have new everything, Hardlines, ls1 calipers, rear calipers, ss brake lines, master cylinder and sent my prop valve to edmiller for adjustment. Thinking about going to a ls1 mastercylinder. I cant stand this plus they wont pass it for inspection with my pedal depressing this far.

InfernalVortex

iTrader: (4)

You can disassemble and replace the dust boots and seals for less than $5 a side. I did it last week. All you need is the right technique with the dust boots and an air compressor. Unless the pistons are in awful shape it's a pretty simple job. I'd never done it before and it took me 30 minutes, and most of that was just messing around with my buddies and trying to figure out how to get the dust boots on the pistons AND in the calipers.

Gumby

those with problems still what kind of brake pads are you using?

sure you all have seen my thread
https://www.thirdgen.org/forums/brak...orgetting.html

I got some fancy $70 pads from autozone with lifetime warranty during the first go round.

fancy pads usually need heat, with less brake power that means less heat. Im was thinking of trying some $10 AZ pads that will blacken the rims and wear out in two years but its another gamble as Im down to only replacing new parts with new parts.

84Camarodriver

My problem was my front flexlines I changed them and my brakes work great of course I had to bleed them its almost like a 75/25 brake bias

Gumby

getting allot more action from $10 copper metalic pads from autozone.

Tobias1977

So I have a question here that I didn't see answered. I just put in a new master cylinder, pads, rotors and calipers. I bled the brakes thoroughly (went two rounds to make sure) and the pedal pumped up perfectly well with the car off. Once I started the car, the pedal went to the floor. It won't pump up. When I turn the car off, it pumps back up again. What am I missing?

The brakes worked before, but the calipers were crapping out so I replaced them and figured I'd get the master cylinder because the fluid was turning black and had been for a while. I replaced in case of damage to seals, plunger, etc. I bled fluid through everything until all the black was out and new fluid was streaming out, no bubbles. I bled in the right order and bench bled the master cylinder before installation.

Thoughts?

MAC_87

iTrader: (3)

I'd guess you dont have a caliper bleeder tightened all the way or a small hole in your brake lines that only takes effect when the booster is active (more pressure forced/applied)

MAC_87

iTrader: (3)

Does anyone legitimately notice a difference between Dot 3 and Dot 4, that have switched over? i'm considering doing this to see if theres any difference.

Gumby

http://viragotech.com/newtech/Brake%20Fluid%20Facts.htm

Tobias1977

I tightened them all down when I bled them. There was no leak in the line previously, there isn't a leak in the line that I can find.

b_the_j

the difference between dot3 and dot4 is that dot4 is synthetic and has a higher boiling point...also it is non-hygroscopic meaning it doesn't pull moisture from the atmosphere as easily. dot3 boils at a lower temp once it builds moisture and is recommended to be replaced yearly, also the moisture build-up from 3 causes corrosion in your calipers and master cylinder, number one cause of failure...

if your pedal goes to the floor with the engine running...you still have a small amount of air trapped somewhere

Tobias1977

It seems that new calipers come with new brass washers. They need to be tightened down extra tight because they're goofy sometimes. Check your washers when installing new calipers. My issue was the one on the driver side. Tight but not tight enough, apparently. Gotta mash that sucker on there. And now we know.

glen_miss3

This may help....
www.realfixesrealfast.com
videos
scroll down click on service
then brakes
brakes hard to bleed

my86bird

I had a wierd idea that I'm not brave enuff to tackle, but is it feasible to increase the diameter of the brake lines, thereby pumping more fluid to the brakes? I have no idea of how to connect these fatter lines to our existing systems, but it sounds to me that those who have upgraded their systems seem to be getting better braking. Or am I misunderstanding what I'm reading? If this is feasible, then maybe some kind of strange"abortion" plumbing adapters at the wheels might help. Or am I just being stupid?

HankL69

iTrader: (1)

The amount of fluid that comes out of a brake line is the same as the amount of fluid that goes in. A larger diameter line will have no effect on the amount of fluid pumped or the pressure it is pumped at.

GMan 3MT

iTrader: (4)

FWIW, I've tried the jack-the-rear-of-the-car approach a while back. Even with the front wheels on blocks of wood, I couldn't get it high enough to get the master level before the nose hit the ground.

I've got an issue I'm looking for advice about. I went to replace my brake fluid, and I let the rear resevior go 'dry' when bleeding. Obviously, this led to a really spongy pedal. So I took the master off to bench bleed it. Put it all back on, bled at the calipers, and it's still not any better. Repeated the process, got a few more bubbles when bench bleeding again, bled at calipers, still not any better. What am I doing wrong?

Put master in vise, slowly depress piston about 1" until there are no more bubbles. Some places say that it should get hard to push? Mine didn't. I stopped after two times without bubbles. Did I not do it enough?

Put the cap back on (2nd time I left the cap off to see if that would make any difference), and remounted to the booster. Removed both plastic fittings and hooked up metal lines. Is it necessary to only do one fitting at a time? I don't see why that makes any difference other than being more difficult and having to bend the lines more. Quite a bit of fluid leaks when hooking up the lines, does that air get trapped back into the master? Or does that air go to the reseviour or does it have to be 'pushed' all the way out to the calipers? I later read you should have someone lightly press on the pedal when you hook up the lines. Necessary?

Pushed a lot of fluid thru the lines when bleeding at the caliper, well, a lot in my opinion. About how many times does it take to get new fluid/air to the caliper? Maybe again I'm not doing it enough?

Thanks!

naf

iTrader: (7)

Last I bench bled I must have pumped it 50+ times. At least a dozen times with no bubbles coming out to be absolutely sure.

I've also been able to clear one in the car with the rear jacked up and the master disconnected from the booster so it would tilt farther forward while the lines were connected.

When installing it the ports are temporarily open, but the fluid dribbling out should prevent any air from coming in.

MAC_87

iTrader: (3)

I found this device on a 91? 92? camaro, Connected by hoses from the plenum and from the booster. Threw the part on mine and the car brakes a Lot easier, it still wont lock up/brake super efficiently, but t least im not pressing the pedal to the floor by any means anymore.

chazman

iTrader: (4)

What is that thing? Some sort of check valve?

MAC_87

iTrader: (3)

It appears so

MAC_87

iTrader: (3)

It's the item Fire is mentioning here, i believe. I have yet to see this item on anything prior to 1990 camaros though. all else appear to be straight from booster to intake.

chazman

iTrader: (4)

I was just under the hood of my '83 and it also has one of those thingamajobbers.

FireDemonSiC

It's supposedly a "Vacuum check valve" although alot of places also list it as the "Power Brake Booster Filter".

MAC_87

iTrader: (3)

Hmm wonder what determines which ones have that thing, and why.

RBob

iTrader: (1)

The canister is just a filter, no check valve in it. From my observations of many cars & trucks at the JY's, there are two different check valves. Scroll up to the picture and in the lower left is the check valve. This holds the vacuum in the booster.

That check valve is the older standard version that has been around forever. With that check valve GM started to use the filter canister (maybe when engines got ECM control? Both CCC & EFI?).

There is another type of check valve that goes into the booster. It is larger and more 'bulbous' (hope that's the right word) then the one shown in the picture. With that check valve the canister filter is not used.

RBob.

Azrael91966669

this is not a check valve its a catch can of sorts its ment to catch fuel from the intake so it cant get in the brake booster
it has charcoal in it in a little baggy ive broken one open before only reason i know whats in them

its found on all Tbi cars and should be on all carb cars
it isnt needed on Tpi/mpfi cars no fuel in the plenums
the most it might be doing is giving your booster less intake vaccum so it firms up your pedal that way
but honestly it should NOT change the way a car stops

MAC_87

iTrader: (3)

Yeah thats what i meant by it brakes easier, it firmed up the pedal.

Azrael91966669

sadly tricking your mind with a firmer pedal isnt solveing the real issue
i have the same problem with spongy pedal i have done everything
i have replaced all rubber hoses ive replaced the master 3 times
i have replaced cleaned out all metal lines ive even replaced all 4 calipers
i also have the C4 front brakes and 91 z28 rear disc
my car used to stops fine from high speed but low speed it dosnt want to stop
i solved that with using cheap semi metalic pads on the front
pedal still spongy takes 2 pumps to get the pedal to feel good
this is the only car i have ever had an issue with ive just never been able to get the pedal to firm up and ive never been able to lock the front brakes
i also do not have the ebrake working

pedal firmness seems to come from the rear brakes i learned that long ago with worn out rear brakes the pedal will always feel spongy
mind you this dosnt help in my case put new rear pads on and i still get spongy brakes

MAC_87

iTrader: (3)

replacing almost every braking componant isnt solving the real issue either apparently, lol.

(And no im not taking a crack at you, ive also replaced hella stuff.)

My braking efficiency and pedal braking distance has been improved tho from when i first got the car. so im content for now. just wish i could lock the brakes.

Azrael91966669

i know but my issue was in more so the fact the car dosnt stop like it should unless i pump the pedal
i traced the issue on mine to the 2 rubber grommets "seals" on the master where the Reservoir hooks up after about a month of driving they start sucking air in
ive replaced the seals and complete masters to no avail after so many miles they start sucking air again hence giving me air in the lines spongy pedal feeling i have another thread about it

point was i replaced everything to make sure there wasnt a problem somewhere else

i expected when i did the C-4 brake swap that the car would stop better it did for a short time .
but found out it was only because i was given the incorrect brackets to mount the caliper brackets to the spindles and it was rubbing the rotor .

as soon as i fixxed ie correct brackets new rotors and pads that i noticed the car just didnt stop well couldnt lock the brakes even when trying to , even the stockers could do that .
but atlest the pedal feel was fine
then i decided that i would swap rears for better gears and matching rear disc
once i did that swap the pedal has been crap ever since
changed to the 1le prop valve no differance it had been this way for 2 years
till my girl got in the car when i was under the hood for what ever reason she hit the brake pedal and i heard a hiss coming from the master.
i checked and it turned out to be the seals for the Reservoir so i picked up the seals
perfect pedal feel and good brakeing for about a month till i noticed the gradualy getting spongy again
i check the seals they are hissing again
so i replace the master get about 4 months and spongy again same seals hissing again
take back the master swap in a new one got less then a month same damn seals
so ive just started going to junk yards and pulling the seals atlest they work for a month or 2 no body else seems to have this problem so who knows but then again im not sure how meany people do this swap and use it as a daily driver
maybe they just dont drive as much and thats why they havent got the issue yet
its as if im building 2 much pressure for the seals to handle i almost think its because the master isnt ment for these calipers

hell maybe ill re add the fuel catcher maybe i am getting to much boost and thats the problem this car was stock a tbi and used that maybe the boosters are differant
i seem to find you cannot trust what part stores tell you since most of the time they say all parts are the same yet they are not

RBob

iTrader: (1)

It sounds like (no pun intended) the seal in the booster is bad. This is the one that goes into the recess where the M/C bolts up. If that seal is bad or missing vacuum would be applied to the back of the M/C. Would also likely hear a leak there too.

RBob.

ZZ3 Z28

Until recently my '86 sat on jacks for 13 years and the only problem with the brakes I've had is a leaky left rear brake cylinder, since replaced. I bled using a one-man bleeding system that worked better than I expected. I was careful not to let the master go dry or low on fluid. I too have spongy brakes but don't believe there is a major problem, yet. I may have a booster at the end of it's life like some others here but will deal with that when the time comes.

I am not discounting any one's problems here but I tend to believe that some of my problem, quote-unquote, is me and the electrically assisted brakes on my new car that make my Camaro's brakes seem like well, antiquated. My new car has all sorts of electronic gizmos that the Camaro doesn't. Its like comparing a bi-plane to a rocket ship. So when I get in my 26 year old car, I have to change how I drive because I don't have electro-mechanical steering, independent suspension, electronic stabilization, anti-slip regulation, cross differential control, electronic differential lock, and etc. etc. etc.

ZZ3 Z28

I have the same filter 17070814 on my '86 Z. It goes from the booster to the rear of the carb.

Marblemadness44

I just read all three pages of posts, so it's clear I have the same "spongy" brakes haha. Weird how common this is...so what was the number one verdict to fix this issue?

FireDemonSiC

Changing out my master cylinder and bench bleeding it made the most notable difference.

When I removed the c-clip and pulled the pistons out of the old one, words cannot describe how much black sludge and gunk was accumulated all over the internals. Not to mention the seals didn't feel as pliable as the "new" one I put in.

Marblemadness44

I will have to look into this in the future. I don't know a whole lot about brakes, is this something I should change immediately? Meaning is the next step complete brake failure?

FireDemonSiC

Unlikely to happen all of a sudden and we don't even know if that's the problem. Could just be air in the lines.

norcalz28

iTrader: (13)

I bench bled my original master thoroughly when I did my c4 brake upgrade, but the car doesn't stop well at all. I can stand on the pedal and it won't lock or set the car down. It's fine for around town and what not, but in a panic situation, I'm toast. I've been convinced to purchased a newer style 4th gen master and install that, see how things go. I like the threaded cap for pressure bleeding. I bought an adapter to pressure bleed the 3rd gen master, but I can never get it to seal, and end up losing good fluid. I'll try it and post up any results. Always felt that the car should stop much shorter than it does with this setup.

Will

RBob

iTrader: (1)

The LS1 M/C has a larger bore then the stock '89 M/C. So pedal effort will go up.

Be sure to use a good pad compound such as the Stoptech High Performance street pads. Many low dusting and/or lifetime pads don't stop.

RBob.

KITT1983

iTrader: (3)

what Stainless steel caliper brake lines will work on my 83 trans am ?

KITT1983

iTrader: (3)

I am having this problem as well, 70 mph 2000 rpm , and at 40mph 1300 rpm. I have the 1983 trans am WS6 4-wheel disc package

i have a new master cylinder. it is not leaking and it has been bench bled. i have wagner Thermoquiets semimetallics.

my e-brake cables are frozen

naf

iTrader: (7)

The early rear discs rely on the parking brake to keep them adjusted. If your e-brake cable is frozen, your rears are probably not working at all. How rusty are the rotors?

There is also a recall kit for the iron caliper rear that fixes some of its issues. Used to be available through GM Parts Direct: Part Number: 18019028, listed as "Actuator" and included parts for both rear calipers, pistons, springs, seals, etc.

WITH the recall kit these older rear discs may achieve marginally better stopping power than the rear drums.