Brakes and Carburetor

[Michael Rodker]

I have a #s matching '81 with 21,000 miles. I'm the 2nd owner. I have two major problems. The first is the brakes. I've replaced the entire brake system. Calipers, pads, hoses, lines and master cylinder. I've had the brakes bled twice. The system currently has DOT3 fluid in it,...not synthetic. The pedal still goes to the floor, the brake light comes on and it's scary as hell. This happens after I've driven the car several times after each "fix". My "mechanic" suggested changing to a higher # DOT fluid but I don't race this car. It's used infrequently and driven conservatively (honest!).

My other problem is the original Rochester. It's the ECM/electric choke model. I replaced the choke coil because the choke light doesn't go out but now it runs worse than before. Lots of bucking on acceleration and difficult to start. Doesn't idle too well either. Tried getting an Edelbrock replacement but they don't make one for this specific model. Neither does anyone else that I can find. My biggest problem is that I'm not mechanically inclined and really don't know what to do or how to fix anything. I rely almost totally on others. Not a good idea when you own one of these cars. Does anyone know of a carburetor replacement for this model? I'm hesitant to get it re-built because I don't really know anyone who does that well and I might end up with a worse problem.

Any help or advice with these problems will be greatly appreciated. Could you please e-mail to "route66@patmedia.net". Many many thanks.

Michael Rodker

[Jack H.]

Re: Brakes and Carburetor

(1) Find a new local mechanic! Changing brake fluid isn't the answer to brake problem (pedal going to the floor). Typically, it's time for a master cylinder overhaul, getting a good/competent bleed of the system, and/or insuring slave cylinders aren't 'pumping' air into the system due to rotor run-out. Suggest this is a GREAT opportunity to get a 'benefit' from your NCRS Chapter membership by asking who are 'good guy' qualified Corvette mechanics in your neck of the woods!!!!

(2) On the carb, my suggestion is to send the original out to one of the pro restoration shops with good reputations in working on Rochester Q-Jet (Bob Kuntz or Jerry Luck). A mail order restoration will probably run you about the same $$$ as a local carb shop doing a conventional 'overhaul' but net you two advantages:

(A) The pros do this for a living and they'll look for/eliminate the typical wear items (warp, shaft bushing slop) that the local overhaul shop misses and/or can't deal with (carb's 'shot').

(B) The guys I mentioned (search the archieves for contact particulars or thumb through your copy of Driveline magazine), test their work product using either a formal flow bench or 'mule' engine. There are MANY 'experts' doing restoration work who make a given carb look 'pretty' and slap in rebuild kits, but typically they don't fully test the final restored/re-built carb and give a return to factory warranty. The 'good guys' know for CERTAIN that carbs they ship are 'on the money'....

[Michael Rodker]

Re: Brakes and Carburetor

Thanks for your help. I appreciate your suggestion about NCRS Chapter membership. That's a good idea. Will do that first thing tomorrow. Thanks again.
Mike

[Joe L.]

Re: Brakes and Carburetor

Mike-----

As far as I know, there is no current replacement for the QuadraJet used on your 1981. These carbs are hard to find and some parts for them are hard to find. Having yours rebuilt by a specialist might be the best course.

[Jim T.]

Re: Brakes and Carburetor

Michael how was your brake system performing before you replaced the master cylinder, calipers, pads, hoses, and lines? You mention that the pedal goes to the floor and the brake light comes on after driving the car several times after each fix. After the brakes are bled do you have a full and firm pedal? If your answer is yes, then it is my experienced guess that you have excessive runout in the rear rotors. If your rotors a not rivetted to the rear spindle you could very well have excessive runout. One way to fix the problem is to remove the spindles and ship the rotors and spindles to "BAIRS" and have them assembled the way your 81 left the factory. This procedure sure solved the problem on my 70 about 16 years ago.