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Hi everyone, after finishing a series of jobs on my 4runner (timing belt, knock sensor, valve adjustment, fluids change, tune-up and more), I put everything back together and it's running great.
There's only one problem. I noticed what looks like a tiny amount of fuel seeping from the banjo bolt copper washers connecting fuel pipes 2 & 3 to the fuel rails. See before and after shots below: This is before driving This is after driving around for a few miles. Notice the shiny glint on the surface of the pipe where the banjo bolt connects. If you look closely, you can see a tiny amount of gas that looks like it's forming into a droplet. It is very small and when I observed it with the car running it never actually formed into a drop.
I torqued these bolts to spec, so it's a little frustrating to see this. Had I known, I would've tightened them a bit more. I also bought the correct copper washers from the dealer.
I'm posting this to confirm this is a problem that I should remedy sooner rather than later, as well as for any other advice anyone has. Reckon I'll need to take the plenum off again and tighten these up more. On the plus side, I'm getting better at dealing with all the vacuum lines
Additional info: There isn't a really strong smell of gas. I only smell it if I get really close. Also like I mentioned, it doesn't appear to be dripping, just evaporating off.
... I also bought the correct copper washers from the dealer. ...
I'm 99.99% certain that the stock crush washers (90430-12026) are aluminum, not copper. Copper is harder than aluminum, and therefore suitable for the much higher pressures (and higher tightening torques) of brake lines. Your fuel-line banjo bolts are steel into an aluminum casting; you don't want to tighten them beyond spec. In your photos, it looks like you have copper washers.
I've found sources generally for aluminum washers, but even from my brick-and-mortar dealer they're cheaper than dirt. So I've only used either my local dealer or one of the mail-order dealer sites.
It's worth repeating: crush washers are one-time-use. Some will tell you they've reused them, and had no problem (well, at least so far ...). I wouldn't do that.
I'm 99.99% certain that the stock crush washers (90430-12026) are aluminum, not copper. Copper is harder than aluminum, and therefore suitable for the much higher pressures (and higher tightening torques) of brake lines. Your fuel-line banjo bolts are steel into an aluminum casting; you don't want to tighten them beyond spec. In your photos, it looks like you have copper washers.
Scope103 -- they are aluminum, not copper. I mistakenly referred to them as copper. I don't have the part number but got them from the dealership and they are the correct ones.
Update: I tightened the two driver's side banjo bolts and it worked -- no more leaks or seepage. It felt right, they just needed to be snugged up a bit more. Maybe the torque wrench I was using was inaccurate, or maybe I did something wrong. But in any case, I think I'd second Paul22re's point that doing it by feel can be effective. Or maybe torque to spec, then snug it up just a bit more if you can without causing more problems.
I just need to check on the passenger side banjo bolt connections and make sure they aren't leaking. I can just barely see the front one, and it doesn't appear to be leaking. I can't see the back one though. I ordered an endoscope camera off Amazon for $35 that I'm going to use to snake underneath there and see if it is or not. I'll let you know what I find out.
Also -- If my torque wrench was faulty, I'm now questioning the torque I applied to the intake manifold gaskets. There doesn't appear to be any issues with the motor running, but are there signs I could look out for that would suggest they need to be torqued down some more?
Last edited by gregory_wilcox; Aug 14, 2020 at 11:20 PM.