Pressurized oil line

[TooManyIdeas]

Is line that goes from the vaccum pump to the block a pressurized line and what is the thread size on the block. Since the rest of the truck is metric, I'm confused wether or not the pipe threads are American or not

[philip]

Is line that goes from the vaccum pump to the block a pressurized line and what is the thread size on the block.

SD22 Oil Circuitry

Pressure from the secondary oil gallery (pressurized) feeds the vacuum pump. Never thought to measure the pipe thread when I had a new braided line made using the old ends.

[Knucklehead]

Oil ports are 1/8 NPT. That's American. One on the left side for the vacuum pump, one on the right rear for the sender, and one on the right front for the IP. There is also a plugged one just behind the right motor mount that is good, but a bit of a tight squeeze with the mount. There is a plug on the left side just above the starter, but that is the coolant drain for the block.

[TooManyIdeas]

I've been asking everyone I know about the thread pitch for those fittings I appreciate your replies

[redmondjp]

I was thinking about this thread pitch last night, and I'm guessing that it's not NPT (National Pipe Thread), but rather BSP (British Standard Pipe), which is close enough that you can get away with using NPT and some sealer.

The reason I think this is that I used to work at a place where we used Kubota engines in our equipment and we installed VDO oil pressure gauges so we had to tap into the engine oil system. I did some research and found out that all Kubota engines use the BSP threads (we were using NPT fittings and were getting away with it).

Now why in the world would Japanese manufacturers use a British pipe thread? After WWII, both the US and Britain helped put Japan back on its feet, which included getting their industry back up and running. So Britain provided their own tooling to Japan and that started them using the BSP thread. OT but related to this--part of Japan has a 50-hz electrical system (the part rebuilt by Britain), and the rest has a 60-hz system like the U.S., to this day!

[asavage]

Yeah, 1/8" BSP is (from memory!) 28 TPI; NPT is 27 TPI. Pretty close, and I've put one in the other several times. Sealant (or brass fittings) is necessary for this interference fit to work.

I actually had those specs written in the lid of my toolbox for years. I think they're still there -- in storage.

[Knucklehead]

Confirmed.