Never done a master cylinder upgrade
 

I need information about how to go about upgrading my braking system on my 89 RS. I've never modded the braking system on a car before and really don't know where to begin. Any education that can be shared with me is appreciated. It's just going to be for a daily driver but the factory brakes have never been too great. I've had all new parts and they just don't have a lot of stopping power. None of my 3rd gens have been all that impressive in the braking department to be honest drum rear or not.

Re: Never done a master cylinder upgrade
 

i agree with the braking power (lack of), I did the big brake upgrade to LS1 front brakes (BBU vendor here) and swapped the rear from drums to 9 bolt disc and there is a noticeable improvement....Have not changed out the master cylinder yet as things are working and it's raining/cold winter and I'm old....LOL

Re: Never done a master cylinder upgrade
 

I can appreciate that for I too am old! I thought about going ahead with the big brake upgrade but wasn't sure how much it would help without the added pressure of an aftermarket master cylinder and booster. I went to shop for one and they don't seem that expensive but they aren't make and model specific. They require mods. I haven't the facilities to do any major modifications, I was hoping there was one I could just replaced it with that fit out of the box.

Re: Never done a master cylinder upgrade
 

Upgrading the master cylinder wouldn't even begin to be on my radar if I was dis-satisfied with my brakes. It's not the weak spot in the thirdgen brake system.

The weak spot is the relatively small front rotors. The brakes turn forward momentum and energy into heat. The rotors act as a heat sink to absorb the heat and dissipate it to the air around the rotor. When the rotors are forced to absorb more heat then they can transfer to the air, they overheat, which results in brake fading, and potentially the rotor warping. The high heat will also damage the pads, and you'll get glazed surfaces on the pads and rotor from the heat and pressure. Then the brakes are less effective even when they've had a chance to cool down, because the clamping surfaces are polished, and the rotor is no longer flat and in even contact with the pads, etc.

The way you improve the brakes is to increase the size of the brake rotor. A larger heat sink can absorb greater heat before being damaged. More area means more exposure to air through which the rotors can dissipate more heat. Increasing the hydraulic pressure against a tiny pad on an insufficient heat sink is just going to damage the rotors faster.

The most popular upgrade are the LS1 brakes from 98-02 Camaros and Firebirds. For not a lot of money, you get a larger rotor and better caliper. You can choose to go bigger, but ultimately you're limited by what will fit under your wheels. After upgrading the front brakes, I'd look into a complimentary rear disc system, and if I still had problems I'd think about looking at the proportioning valve or master cylinder.

Of course all of this assumes that the stock brakes are 100% functional, and you're simply not happy with them. At this point, I wouldn't trust the stock brakes unless I've personally gone through the system and checked for leaks at the wheel cylinders and caliper pistons, hoses, lines, etc. For that matter I would replace all the rubber brake hoses, the rotors, and pads, and I'd completely flush all the old brake fluid out of the system and replace with clean, fresh fluid, and a proper bleeding. If the caliper pistons don't move smoothly, I'd probably replace them too - they're cheap. Generally speaking, the stock brakes on these cars aren't that bad. They're no worse than any other car from the 70's and early-mid 80's. If they seem worse than any other 1985 car, there's probably something faulty in the system.

Re: Never done a master cylinder upgrade
 

Thanks Drew! I needed info and got it! The system has been gone through years ago and it is due again. I am going from when I had gone through them and bled out all the old fluid and replaced everything that needed it including the master cylinder. They just never have been very good. I did do a small upgrade to the rotors by getting Summit drilled ones because my wife quickly warped the old ones in just one day, but that is about it. I'll go through them again as they do need it and see if i discover anything amiss. Then from there if I still feel an upgrade is necessary I will check in to your advice. Thank you very much. Oh, before I forget, I do have a header pipe about an inch and a half from a line off the master, how much would that affect things? Currently the fluid is dirty but other than that the line is the only problem me and meineke could find.

Re: Never done a master cylinder upgrade
 

I did the LS1 front brakes (with some earl's braided lines) and it was a night and day difference. Stock master, stock PBR rears.

...my headers are about an inch away and I too was concerned but it's never been an issue.

Re: Never done a master cylinder upgrade
 

Thanks for the info. LS1 brakes? What are those off of? A Corvette?