Dartht33bagger

So I know a lot people on the board here have said that their car barely stops. I think my car stops very quickly and I have front disc and rear drum. Did some of the cars come with 4 way drum brakes or something?

If I was ever going to switch to 4 way disc, how hard is that to do, and how much does it cost? Is it cheap or expensive to do?

Also, my car kind of has a lot of braking "air", meaning I have to press down the brakes about 2 inches before it starts breaking at all. It has new pads in the front and rear, so I don't know what it is.

JamesC

iTrader: (5)

Disc/disc and disc/drum are the only options.

Check the following link for info about swapping in a disc rear and/or about swapping on discs.

https://www.thirdgen.org/forums/tran...-10-bolts.html

You may need to bleed the brakes.

JamesC

Dartht33bagger

Ok I looked that over. I have talked to my grandpa and I want to see if this is how it's done.

1. Go to junkyard and find camaro or firebird with rear disc brakes and take mounting brackets, or buy new mounting brackets new from dealer.
2. Buy new calipurs, rotors and pads.
3. Install them all and it should work.

Now my dads friend says he thinks we will need a new master cylinder. Is there a tutorial somewhere on how to do a drum to disc swap on a third gen?

RBob

iTrader: (1)

The stock 3rd gen drum rear brakes are better then the stock 3rd gen rear disc brakes. This is one reason that many folks have difficulty stopping.

That and some use the cheapest front pads they can buy. Never do that. Get good semi-metallic pads. Much cheaper then buying new front end sheet metal.

For those that think their 3rd gen rear disc are better then 3rd gen rear drum, what have you done to the stock factory equipment to make them work correctly?

RBob.

Dartht33bagger

So your saying swapping to disc brakes is worse than keeping drum??

RBob

iTrader: (1)

Stock for stock, yes. Example: The stock rear disc 3rd gen brakes won't even stop the tires from rotating with the rear off the ground and an auto in drive, at idle.

RBob.

JamesC

iTrader: (5)

Though many members have voiced their dissatisfaction with thirdgen rear discs over the years, my experience was gratifying enough. I swapped in the new rear, replaced the lines, threw on new calipers and pads, and bled the lines. Good to go. Were the discs more effective than the drums? Truthfully, I couldn't say.

RBob, I wonder what effect the parking brake could have had on the situation? Would more problems have occurred with autos (or manuals for that matter) when the parking brake wasn't frequently used? Or is the design just fundamentally flawed?

JamesC

spade

iTrader: (3)

and here i thought my brakes were messed up..... so im not the only one...

Dartht33bagger

So then what do you do if you want disc brakes in the rear?

JamesC

iTrader: (5)

Upgrade. There are many choices. One, which is 89-97 PBR's, is shown in the following link:

https://www.thirdgen.org/forums/faq-...iscs-89-a.html

JamesC

Dartht33bagger

So pretty much as long as I get the same disc brakes that would have been on my 91 had that option been added, it would be better? At least that is what I am taking from the post.

JamesC

iTrader: (5)

Yes.

JamesC

RBob

iTrader: (1)

The earlier Delco cast iron caliper rear brakes have design flaws. There is a recall kit for them that helps. But unless one uses the parking brake on a regular basis, there is no real fix for them.

The later PBR aluminum calipers are better, but still have issues. The parking brake set up is difficult to get to work properly. But this doesn't affect the hydraulic portion of the caliper (unlike the Delco calipers).

Neither set up from the factory has the proper proportioning in the combo valve. Simply not enough line pressure is provided to the rear brakes.


The fix for the rear line pressure issue is in the combo valve and/or using an external proportioning valve. A member here actually converted the stock combo valve to have an adjustable proportioning valve (jerrywho). Slick set up.

Can also completely gut the combo valve and plug the center section. The plug is to maintain two separate brake circuits. Or, eliminate the combo valve completely.

Then plumb in a proportioning valve such as Wilwoods. This goes to the rear brake circuit.

Which way to go depends upon how much re-flaring of lines you want to do. As eliminating the combo valve requires a T block and a way to connect into the rear line.

And, using a proportioning valve is important. Otherwise on heavy braking the car may decide to swap ends. So don't just gut the combo and leave it that way.


As for the parking brake fix, go with the '98-'02 f-body rear brakes (the 'LS1' swap). These have a shoe in the drum style. And work. Plus you get a 12" x 1" rear rotor and a single piston PBR caliper (aluminum). Note that I don't believe they will clear a 15" wheel. So keep in mind wheel size if you go with these brakes.

IIRC, there is a tech article here on TGO about fitting the 'LS1' brakes to our cars.

RBob.

RBob

iTrader: (1)

I would possibly go with the '89 - '97 PBR's (as James mentioned). Or, step up to the '98 - '02 "LS1" rear brakes.

Either way the combo valve proportioning set up would be changed. See my post right above this in in this thread.

RBob.

LarryL

My 84 TA had 4 wheel factory power disc brakes. The only problem I had was the rear calipers would stop adjusting after a few years. The car stops as good as expected for its design and year. But nothing like newer setups. I switched to C5 all around and there is a huge difference in stopping. It was not a hard job! Just took time and $$$$. Because I had disc only had to change calipers, rotors, SS lines and brackets. I have 18" vette wheels all around so no issues with clearances. I have done several conversion for local guys and they love them. YES good front pads are a must even in a stock setup. I will not use a pad that will damage the rotors, with D/S rotors nobody wants to cut them if they need it.
So softer brake pads wear fast and cause dust put for me I like longer rotor life. I dont drive the car much now so minor loss in stopping power is not an issue. Ever with minor stopping loss in stopping power they are 100 times better than stock. Right now I am trying to adapt front C5 calipers to the rear. This will NOT increase stopping power just for looks. I take the car to some local car shows. Good brakes are very important and not to be taken lightly, the life you save is yours and others.

Dartht33bagger

LS1 sounds like a good swap. I have the stock wheels on my 91 Z28 though...

87350IROC

iTrader: (2)

The stock iron Moraine rear discs can be made to work correctly, cheaply. The problem is two fold as has been already mentioned. First the e-brake needs to be used on a regular basis. Second you need to raise the line pressure to the rears. You can do this by installing the an adjustable proportioning valve such as the $42 Wilwood.

http://www.summitracing.com/parts/WIL-260-8419/

While I agree they aren't the sexiest brakes ever they do work fine if you take care of these two issues. In fact just last weekend I was out at Pacific Raceway road racing on these brakes. I put 60 track miles on them with no complaints.

cjh1505

so thats why the first third gen i owned i didnt have to do the rear brakes in the 5 years i owned it.

87350IROC

iTrader: (2)

You got it.