The Stovebolt Site Forums The Shop Area General Truck Talk Removing Road Draft Tube On 235

Hi everyone, Im working on a 59 chevy 3100 for a friend and I would like to remove the road draft tube and clean out the 40+ years of sludge in there. It looks like its just pressed into the block but I didnt want to yank on it and break it so I figured I would ask on here. Thanks in advance for the help.

yes it's just pressed in, but they do get a little hard to remove after 40 years

Bill

yes it is pressed in but mine also has a bracket bolted to the block. ron

I have a 56 235, it was pressed a has a bracket that attaches to the block in the part of the block that forms the oil pan rail. Mine was very difficult to get off. I used penetrating oil -- let it soak in and the tapped the tube with a rubber mallet. After repeating these steps 3 or times I was able to free it up for removal. Just excerise patient and all will be fine.

Personally I would recommend either lengthening it and/or filtering it with a modern type filter.

builder - the guy just wants to get it off to clean it out, not eliminate it

Bill

I didn't say anything about eliminating it. I suggested a modification to it.

builder,

What kind of filter would be used and where would it be placed? What would it filter?

Tim

I would place a filter (such as a K&N) onto the end of the draft tube.

What would it filter you ask? What do you suppose the piece of chore boy stuffed in the end of the draft tube filters? The purpose is to keep dirt and debris from entering the tube, which is inturn a direct connection to the inside of the engine case where your pistons, rods, valves, etc. reside.

The air movement in the draft tube will move in both directions (in and out). The pressure inside the engine case changes from above atmospheric pressure to below atmospheric pressure. If it didn't, you wouldn't need a draft tube.

It would help just to attach a long heater hose to the end of the draft tube and run it to the rear of the vehicle, making it less possible for dirt and debris to reach the internal engine.

I am in the same boat, my RD tube needs a cleaning. I guess I will add it to the list now that I know how to do it.

Kyle

I know you guys said you didn't want to modify it... So I'm just adding this comment for whomever else happens by-

The original Road Draft Tube had some fiber in the 'body' of it to filter incoming stuff and condense the outgoing stuff- Rumor has it that it was horsehair. Problem is that over the years it has probably disappeared. I think steel or brass wool might work as a substitute.

Lots of people add a PCV valve to their Road Draft Tube, or replace it. There are a couple of ways I've seen it done-

One way is to do it like it was done on the later engines, with the PCV valve on the road draft tube body. To do it you'd cut the draft tube off the body that sticks into the engine and weld a freeze plug into the hole. Before you weld in the freeze plug you drill a hole in it and weld on a bolt with threads that match a threaded PCV valve. Then you run a vaccum line from the other side of the PCV valve to the intake, which might require the use of a Tee if you have vaccuum wipers.

Another way is to get rid of the draft tube and buy and aftermarket push in valve cover breather with a hose outlet. The you'd use a tee on the intake that you could thread a PCV valve into and then run a vaccum line between the two.

Why convert to a PCV valve? Less oil under your truck, more negative pressure in the crank case to help not blow out the gaskets? Might be more fuel efficient...

See the factory instalation manual sect 0 sheet 4.00.This is a modification that really turns heads at the shows I show my truck at. I taped the manifold to a 3/8 pipe thread and installed a "T" in the place of the octigon fitting showen in "view B" then followed the pics. Works great, not to mention the conversation it produces to and with other stove bolters.I used a 3/8" break line to run to the manifold.

I had a 283 with so much blow-by that i had to hang a tin can at the end of my draft tube... when it got half full, i'd just dump it back into the engine.

I prefer the PVC valve modification tho.