Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - Rochester Quadrajet 4MV Carburetor: Removal, Disassembly, Rebuild (Rookie Level)
View Single Post
  #21 (permalink)  
Old 02-06-2011, 11:31 PM
lt1silverhawk's Avatar
lt1silverhawk lt1silverhawk is offline
"But how do it know?"
Last wiki edit: How to rebuild a Rochester Quadrajet 4MV carbureto... Last photo:
Join Date: Mar 2010
Location: Lakewood, CA
Posts: 2,322
Wiki Edits: 132

Thanks: 143
Thanked 30 Times in 22 Posts
- Reassembly: Phase 1 -

Sealing the Well Plugs

According to research, it seems that the well plugs at the bottom of the float bowls in Q-jets are prone to leak. The plugs on this carburetor were sealed with some sort of silicone (you can see it in the disassembly pictures), but it came off in the dip. I went ahead and sealed it again using 5 minute epoxy (it was recommended in the Youtube video series I am using).

Attaching the Throttle-body to the Float Bowl

Once the epoxy sealed up, I bolted up the throttle body to the float bowl using the two bolts, with a gasket in between.

Installing New Check Ball

Reinstalling Jets

Preparing and Installing New Float Needle and Seat

Preparing and Installing New Float

The new float was prepared by hanging the new needle and installing the pivot rod. The float was then installed by placing the needle in the seat and installing the pivot rod in its brackets.

The height was adjusted according to the instructions. For this particular model, it is 11/32" of an inch. Once the float is installed, the height is measured from the toe of the float to the top of the float bowl wall. The height is adjusted by gently forcing the metal bar on the float up or down using some needle nose pliers.


Power Piston Retain Cap Question

After setting up the float, I tried to install the power piston but, the retainer cap at the top of the piston that pushes into the tube will not stay in place. I can only assume that I somehow damaged it during disassembly. Of course, now the piston doesn't stay in place and the rods aren't sitting in the jets.

Is there any fix to this, aside from purchasing a new piston or a replacement bushing? New parts are sold here.

As always, all help greatly appreciated!

Last edited by lt1silverhawk; 02-06-2011 at 11:46 PM.
Reply With Quote