Vacuum hose replacement

A lot of my vacuum lines are starting to get cracked at the ends and have probably never been replaced (2008 4.0L). I'm assuming vacuum leaks from those are why my fuel trims are in the 6-8% range.

Looking at replacing everything and the OEM lines are stupid expensive for what they are so I'm thinking of buying one of the silicone vacuum line kits off Amazon.

I'm assuming a pack of 4mm/6mm/8mm/12mm would cover all of the sizes we'd need, right? I'm at work and can't measure or go look at the truck currently, hoping someone has done it before and knows.

Also, I know silicone breaks down with oil/gas, the PCV line into the airbox is the only line that would potentially have oil/gas in it, correct?


TIA,
Spencer

 

Looks like most silicone hoses in the larger sizes collapse under 18-20 inches of vacuum. Anyone know off the top of their head how much vacuum an NA engine pulls?

 

6-8% is a normalish range for fuel trims tbh.

 

I always thought anything about 5% is cause for concern? Even if that is normalish, I can see splits in some lines near the connectors and have to assume it's leaking some. For $40 for a kit might not be bad to take care of anyway.

 

I dont think you will technically throw any codes till 20% LTFT's

That stated, yeah if you wanna replace the few vac lines go for it. Really on an NA application there are the two small lines for the ACIS valve, one small one for the FPR. Then the two bigger ones for the PCV, and for your truck that likely has a vac boosted master, that line (definietly get proper vac booster line for that). And the PCV id be inclined to get OEM part number replacements as they have proper bends in them.

 

Already replaced the PCV lines with proper hose when I put in my catch can. I'll measure the rest of the lines at some point this week and see if the $40 Amazon variety pack will cover the rest. YOLO, I guess worth a shot

 

Auto parts store should have vacuum line by the foot, you will only need one size for the ACIS and FPR lines... maybe 3ft or less. For likely 50 cents a foot.

And Vac booster line you absolutely want to get proper lines for that.

 

spencermarkd, did you replaced the hoses, I have 2011 tacoma 4.0 and I am thinking using silicone hoses too.. Hope to hear from you. Thanks and God Bless.

 

I know I replaced a few of them, I don't remember if I replaced all of them or not, sorry. It's been five years and I sold the truck two years ago haha.