QuadraRot Rebuild

[pkbinplano]

Truck needs a accel pump. Never took apart a Rochester Quadrajet. Any advise ? Bogs when floored

[caminokid]

Originally Posted by pkbinplano

Truck needs a accel pump. Never took apart a Rochester Quadrajet. Any advise ? Bogs when floored

I would just go find another one. You'll find its easier to replace a carb then to rebuild one.

[Bad Karma]

You're looking at this all wrong. Q-jets are great carbs, once you get to know them. Get the Doug Roe book and the Haynes(?) on Quadrajets. Great info, they're super easy to rebuild and tune. The books saved my butt when emissions-testing came around a couple years ago.

[mckpaul]

Quadrajets are not all that hard to rebuild. A kit to rebuild it only costs about $20. You also need to buy some stuff to dip or soak everything in that costs about $20 as well, and you really need compressed air available to blow out all the passageways. Carb cleaning spray is good for this too, but be forewarned. If you stick the little red hose on the carb cleaner spary can to spray through and blow out a passageway, don't assume every hole will blow through, and hold it so if the hole you're spraying into happens to have a bottom (as opposed to a passageway that will blow out somewhere else) and it back sprays back at you, that it will not spray in your face. If that stuff back sprays into your eyes, you'll think a mule kicked you in the face and you won't be able to open your eyes or see for about a half hour. Not that that's ever happend to me, nope, never done that.....

The books mentioned are helpful too. There's a couple of places that need to be epoxied that are known to leak inside, and usually, as old as these things are, they are bad about needing to have the throttle shaft holes rebushed. When they get worn around the throttle shaft, it creates a vacuum leak. I found a place to bring the throttle plate to and have it rebushed for $35. You can buy kits to do it yourself, you get a drill bit and bushings, but unless it's something your going to do again on other quadrajets, it costs more to buy the kit than to just have a shop do it.

They really are good carbs after being rebushed and have a kit put in them and the right spots epoxied.

[Yankeelights]

Here's a few sites about rebuilding & tuning Quadrajets. This first one has a great photo to identify the lead plugs to cover with epoxy. Before I use the epoxy, I rough up the lead plugs and the area around them with a little stainless steel brush. I use JB Weld and let it set overnight:

http://www.circletrack.com/techartic...uadrajet_tech/

Another article:

http://www.chevyhiperformance.com/te...et_carburetor/

This will help once you get good at Quadrajets and you want to tune it to your engine. I recommend a basic rebuild for your first; then pick up another carb to squeeze out some extra umph!:

http://www.highperformancepontiac.co...uretor_tuning/

This is a great article for tuning Quadrajets; close-up photos:

http://www.geocities.com/wag1comet/q.../quadrajet.htm

Parts Sites:

http://www.carburetion.com/quadrajet.asp

http://www.carburetor.ca/carbs/tech/...jet-index.html

http://www.jetchip.com/products.asp?pid=27486

Have fun rebuilding the greatest carb ever designed!

~ Dave

[randyjohn]

i just rebuilt my 4 barrel rochester q-jet last week and what a difference. better idle, rev, accel. i used the service manual from the manufacturer that i found a link for right here:

http://www.tocmp.com/manuals/Carbs/R...QJet/index.htm

5 hours and 25 bucks for the kit and i couldn't be happier with the results.

[PhilaTruck]

And if you don't want to do the complete rebuild, just do the accel pump. They're pretty easy. Just save the rest of the kit. I can personally recommend the Doug Roe book.
Man, there are some great posts here. Good luck.
-Todd

[jimfulco]

And never, ever, ditch the original carb that came on your vehicle. You can buy rebuilt carbs all day, even brand new ones, and they'll never work as well as your original will, once it's rebuilt by somebody who knows what they're doing. I once bought a brand new Q-jet, supposedly the right one for my car, and it never ran better than "half-fast". I finally got the original rebuilt locally for considerably less than I paid for the new one, and the car ran like it was brand new.