How do you seal a brass fitting screwed into a steel carburetor or sediment bowl?

   #1  

Jstpssng

Super Star Member
Joined
Aug 7, 2005
Messages
15,318
Location
Maine
Tractor
Kubota L3301
Do I just turn them in dry until they stop or ?
I just put a new sediment bowl and carb on my (gas) TO35 and ran new fuel lines. Tomorrow I need to move it back undercover and would like to just dump fuel into it and go.
Does brass seal onto steel, or whatever metal they are made of?
Thank you.
 
   #2  

Roadworthy

Veteran Member
Joined
Aug 24, 2019
Messages
2,183
Location
Southeast Washington
Tractor
Kubota L2501 HST,
Carburetors are usually made of "pot metal" (aluminum). When screwing in a brass fitting, if the sealing surface is flat, usually a fiber or copper washer is used to make the seal.
 
   #3  

4570Man

Super Star Member
Joined
Apr 7, 2015
Messages
15,039
Location
Crossville, TN
Tractor
Kubota M59, Kubota L3800, Grasshopper 428D, Topkick dump truck, 3500 dump truck, 10 ton trailer, more lighter trailers.
They usually have a sealing washer on them.
 
  
  • Thread Starter
#4  
OP
J

Jstpssng

Super Star Member
Joined
Aug 7, 2005
Messages
15,318
Location
Maine
Tractor
Kubota L3301
Thanks, I knew that something wasn't right. They must have fallen out of the package, so I will have to come up with something.
 
   #5  

RickB

Super Star Member
Joined
Sep 18, 2000
Messages
14,585
Location
Up the road from Dollar General WNC
Tractor
Just a Scag
There are several different connection types. Straight thread will need a sealing washer or o ring. Flare or inverted flare seal without anything. Many inlet fittings are pipe thread and will require dole or thread tape.
 
   #6  

skipmarcy

Platinum Member
Joined
Apr 15, 2005
Messages
999
Location
Erin, Tenn.
Tractor
2001 Mahindra 4110
If it is pipe thread I would use Teflon tape. You have to apply it properly though. Always leave the first thread or two bare of tape so it won't string-off and get into the system. Be careful with pipe thread too that you don't overtighten and split the unit you are screwing into - the Teflon tape will make it easier/smoother to screw in and is easy to over do it.
 
   #7  

TractorGuy

Elite Member
Joined
Sep 15, 2013
Messages
4,481
Location
N. FL
Tractor
John Deere 4310 CUT, Ford New Holland 575E Industrial Backhoe, John Deere F725 Front Mount Mower
For a tapered pipe thread with gas or oil I put a dab of Aviation Permatex on the threads.

As has already been said, most carburetors will have a straight thread with a sealing washer or flare type fitting.
 
  
  • Thread Starter
#8  
OP
J

Jstpssng

Super Star Member
Joined
Aug 7, 2005
Messages
15,318
Location
Maine
Tractor
Kubota L3301
Thanks for the advice, now I know what to do next time. The lines are both flared so I guess that I'm OK. It's been 3 weeks since I hooked it up and couldn't remember how I had done it.

It turns out that was the least of my worries. I left the house at 4 this AM, hoping to get down there and get the tractor inside before it started raining, allowing me to change out he water pump while listening to the rain on the shop roof. Even if the lines leaked a little I could fix that once I got it inside.
After shutting the petcock off I dumped about a gallon of gas into the tank and went inside to get the battery. When I came out the fuel was running through my new petcock/sediment bowl, through my nice shiny new copper fuel line theway that it's supposed to and out my nice new $173 carburetor onto the ground. I pulled a tarp over it, went down and visited with my mother for a while, and came home. 8 hours on the road for 10 minutes of work... but at least the tractor is covered, rather than setting out in the rain.
 
 
Top