Vacuum hose line inner diameter size???

[rit14623]

Okay, so I see a vacuum line that appears to be cracked but not leaking. It is coming up from the intake manifold and goes to this cylindrical housing on the passenger-side firewall.
Anyway, I've never changed vacuum lines. I don't see in my pdf manual what the inner diameter size I need. Anyone know? I don't want to get the wrong size. Or, do I just go to NAPA and they'll know what hose size I need or is there a URL with that info for a Protege5?

So to add to that, I'd like to "dress-up" my engine bay a little bit and get silicone hoses. They come in various innner diameter hoses. It doesn't seem obvious which size I need. I don't want to eyeball it and get the wrong size hose. http://www.boostcontroller.com/index.php?category=8

Can I just measure the outer diameter of the fitting it goes on? I am guessing a 3mm inner diameter hose is going over a 3mm outer diamter hose line fitting, but it would seem to be proper to get a tight fit on the fitting so the inner diameter would be a bit smaller than the hose line fitting's outer diameter. Thanks for your help.

 

[pcb]

If it were me I would just eyeball it. Vacuum lines are quite flexible and expand quite a bit when pushed onto a nipple. You might consider pulling one end of the line off and cutting an inch off to use as an example for the parts guy then re-attaching the line. Make sure he doesn't use the swelled end for the measurement. I think the line diameters are pretty much standard.

 

[pcb]

I just went out and looked at my car and it looks like you're talking about the line going to the charcoal filter. I didn't realize that the hoses came in 1/2 mm increments. I would pull each hose off individually and measure the size of the nipple. Most nipples have a ridge on them to make sure they don't fall off. Don't measure the swelled part use the area above or below the ridge for you measurement.

When you remove the line, don't just pull on them,... give it a twist first with your hand or pliers to break it loose. They can get gummed up and almost glue themselves onto the fitting.

Those special lines you're interested it may very well have different wall thickness so you want the I.D. for each fitting.

 

[cornrickey]

Cut a piece of it off and take it to the auto parts store.

 

[rit14623]

So, just to follow up. I wanted to replace the vacuum hose that goes from the intake manifold to the cruise control actuator. It was cracking from the outside. After later inspection, it was cracked only half way through and wasn't leaking. Anyway, I took it off and the end that goes into the intake manifold is enlarged more than the cruise control actuator's end. So, I went to the auto parts store, and got a two foot piece of 5/32" inner diameter (I.D.) vacuum hose. The outer diameter was a bit larger than the one I removed.
This would equate to 4mm I.D. hose FYI. I cut off about 2 inches and replaced the hose. Pretty simple.