I have a 1985 Iroc running a TPI and 4 wheel disc brakes. While the car stops o.k. it seems like a lousy pedal that travels further than I think it should. I've been told all gen 3's with a TPI have lousy pedals as there isn't enough vacuum to help the booster. If this is true, is there an option to fix the problem? Or am I just expecting too much from 1985 technology? My 2000 Jeep Wrangler has a far better feel so that's my comparison each time I drive it. Thoughts?

 

Only time I ever had a bad brake pedal on one of these cars was when there was an issue like bad rubber lines or air in the line.

 

there is no way you can compare a 85 - a 2000


but you should try to bleed the lines and replace the old fluid, and at that age, you should probably also change the rubber hoses...they are probably degraded and allowing for expansion with pressure etc..

 

That is not true. If the engine isn't running well, it may be providing low vacuum, but the stock setup working properly should still give a firm pedal that actuates like you'd expect. The performance isn't mind blowing, but the feel should be pretty good.

Sounds like you've got a problem with your brakes, though. A fluid flush is an easy and cheap first diagnostic.

 

If the rears aren't relatively adjusted up then the pedal will be low. Much more common on a drum brake system but still applies to this vintage of disc brake.

 

One of the reasons GM switched to the later pbr calipers was those rear Delco moraine calipers. They had a tendency not to self adjust like they were suppose to. Could be that's your issue. Usually you'd have a gap between the pad/rotor. I always used to manually adjust them, eventually I just upgraded to the pbr style.

 

So I actually had all the wheels off the other day just to polish and clean the backsides and I had my step on the brake pedal. No rear brakes to speak of, didn't even act like it wanted to do something, then up front, just the passenger side, yikes! So, bought all new pads, rotors and calipers, plus stainless replacement lines. We'll see how that works out! If I fumble through and only got one more brake to work, I'd still be 100 % better off! HAHAHAHA