Hewitt Bypass Kit While Fixing Valley Plate Leak? (1 Viewer)

[jjtrou2072]

I have a 2013 LX with right at 200K miles.
Recently developed the Valley Plate leak.

I plan on keeping the rig a long time and enjoy taking the family camping in fairly remote areas.
I want to PM anything that might lead to a no start / limp mode situation.

With that being said I am gearing up to tackle the valley plate leak but was wondering what the consensus was on ordering the Hewitt bypass kit and pulling out the air pumps / sensors while I am in there?

No issues with the SAIS system for the first 200K miles, but what is the likelihood of another 200K trouble free?
Is this overkill?

As a reference I plan on replacing the starter next just for peace of mind.

 

[OregonLC]

I definitely would consider that. Though I seem to remember there being some issue with the physical removal of the pumps using the blankoff plate vs simply the placebo jumper. Would recommend you vetting this out. The only reason to do it as a 'while you're in there' would be to remove the plumbing bits and if that has a risk of a secondary problem then it might be wise to just leave it.

 

[bloc]

I don't know if our hardware is different than the 5.7L tundra guys but we don't seem to have many posts about problems with the SAIS on this platform.

Not that this is necessarily a bad idea.. just that we don't seem to need it as much as they do.

Also the intake manifold is a really quick job when you know a couple tricks. So personally, I'd wait until I had SAIS issues to spend the money and time. But that's just me.

 

[jjtrou2072]

So it sounds like the odds are in my favor leaving the SAIS system alone.
I guess I will put that money toward a new starter.

 

[kossykoss]

I removed my entire SAIS when doing the valley leak. Once you try putting the air switching valves back in you’ll be in literal hell. Less garbage under the hood too. If you remove the valves like I did you will have to spend extra on hewitts pressure sensor addons. They’re pricey. I also cut the flanges off the pipes that run from the valves to the exhaust and had a shop weld plugs in the holes. I used that custom flange to sandwich some new gaskets on both sides.

 

[gon2mnts]

I just rolled 200 on mine and I’m considering the same thing. It seems pretty involved to remove everything I must admit.

 

[nwfl4runner]

Having done that job this past April I would 100% do it. Easy access. Mine had 170k and when i opened up the valves it was clear I was on borrowed time with the corrosion.

 

[jjtrou2072]

I removed my entire SAIS when doing the valley leak. Once you try putting the air switching valves back in you’ll be in literal hell. Less garbage under the hood too. If you remove the valves like I did you will have to spend extra on hewitts pressure sensor addons. They’re pricey. I also cut the flanges off the pipes that run from the valves to the exhaust and had a shop weld plugs in the holes. I used that custom flange to sandwich some new gaskets on both sides.

If I go down this road I would want to remove the whole system like you did.
Man, they are proud of those pressure sensors. $225 each is wild.

If I understand correctly, we need 2 sensors so the total cost to get rid of the SAIS system and eliminate all related codes would be around $1,000 on top of the parts required to fix the valley leak.

It's alot but I will probably just bite the bullet.
I drive this thing across country every summer with the family so I would rather err on the side of caution.

 

[unclemat]

Any concerns about their sensors' longevity? Is it some bespoke part, or they found something, adapted and charge arm and leg now?

 

[cphibs]

For anyone reading I have a brand new hewit bypass kit I will sell.

(Now that I’m posting this, the code will come back and I’ll need it…)

Edit: sold

 

[unclemat]

I removed my entire SAIS when doing the valley leak. Once you try putting the air switching valves back in you’ll be in literal hell. Less garbage under the hood too. If you remove the valves like I did you will have to spend extra on hewitts pressure sensor addons. They’re pricey. I also cut the flanges off the pipes that run from the valves to the exhaust and had a shop weld plugs in the holes. I used that custom flange to sandwich some new gaskets on both sides.

So you eliminated these pipes completely and plugged the openings at the exhaust manifold vs. using the block off plates Hewitt sells and the end of the tubes?

I read the bolts at the exhaust manifold can snap on rust belt trucks and then you are in world of hurt.

 

[unclemat]

Any concerns about their sensors' longevity? Is it some bespoke part, or they found something, adapted and charge arm and leg now?

I am asking because that sensor's shape is exactly like manifold pressure sensor on 4th gen turbo Subaru Legacy. I think it is a cheap part in the aftermarket, like $30. Of course we would need to know the electrical specs to be sure.

 

[lx200inAR]

I removed my SAIS while replacing my intake manifold. I did similar to above, but I ended up leaving the valves in. Couldn't justify spending 400-500 for new sensors from Hewitt. I removed the pipes that go towards the pumps and removed the pumps as well. I disconnected the hard lines that go towards the exhaust manifold and then cut everything down to the part that bolts to the exhaust manifold out. I left that part installed so that i could have something to bolt the blockoff plates to.

Hewitt acknowledges the cheap aftermarket options but says they have tons of problems with them and that is why they only use Toyota (or expensive) sensors. Not sure from what vehicle. If that could be figured out, possibly they could be procured cheaper than what Hewitt sells them for. I'm pretty sure you can buy OEM valves with the sensors built in for the same price or slightly cheaper than what Hewitt sells two sensors for.

The Hewitt kit has worked well for me, so not going to complain about it, but as far as the sensors go, it would not surprise me if they could be found cheaper. I wanted to order a new wiring harness to get back to the sensors from Hewitt and they asked $125 for a few feet of high gauge wire and connectors. So it wouldn't surprise me if they were marking up the sensors a good bit as well.

 

[unclemat]

I removed my SAIS while replacing my intake manifold. I did similar to above, but I ended up leaving the valves in. Couldn't justify spending 400-500 for new sensors from Hewitt. I removed the pipes that go towards the pumps and removed the pumps as well. I disconnected the hard lines that go towards the exhaust manifold and then cut everything down to the part that bolts to the exhaust manifold out. I left that part installed so that i could have something to bolt the blockoff plates to.

Hewitt acknowledges the cheap aftermarket options but says they have tons of problems with them and that is why they only use Toyota (or expensive) sensors. Not sure from what vehicle. If that could be figured out, possibly they could be procured cheaper than what Hewitt sells them for. I'm pretty sure you can buy OEM valves with the sensors built in for the same price or slightly cheaper than what Hewitt sells two sensors for.

The Hewitt kit has worked well for me, so not going to complain about it, but as far as the sensors go, it would not surprise me if they could be found cheaper. I wanted to order a new wiring harness to get back to the sensors from Hewitt and they asked $125 for a few feet of high gauge wire and connectors. So it wouldn't surprise me if they were marking up the sensors a good bit as well.

New Denso pressure sensors are like ~$130 from Rockauto. They should be same/comparable quality to Toyota OEM. That's more reasonable cost. The little adapter harness would be needed since it seems the connectors on the valves are different than on the sensors. I asked them if they would sell them separately.

 

[jjtrou2072]

New Denso pressure sensors are like ~$130 from Rockauto. They should be same/comparable quality to Toyota OEM. That's more reasonable cost. The little adapter harness would be needed since it seems the connectors on the valves are different than on the sensors. I asked them if they would sell them separately.

It dont mind a DIY approach the sensors.
Interesting to see where this leads.

 

[unclemat]

It dont mind a DIY approach the sensors.
Interesting to see where this leads.

Yeah, and I really like the idea of fully yanking out SAIS, including the tubes on the exhaust manifold.

 

[lx200inAR]

I will say, it’s really not a big deal leaving the valves in with all the plumbing removed. I was just hoping to not have the extra wiring. Here’s a shot of mine with everything removed.

 

[DrivenLyfe]

I just did the Hewitt bypass installation. It would be a lot easier if the intake manifold was off. I need to do the block off plates still but they are soaking in PB blaster.

 

[04UZJ100]

If you install the wiring bypass on a functioning SAIS, isn’t there no need for block off plates?

 

[lx200inAR]

I just did the Hewitt bypass installation. It would be a lot easier if the intake manifold was off. I need to do the block off plates still but they are soaking in PB blaster.

Yeah, when I actually did the install my manifold was still on. It certainly isnt impossible, but it’s difficult. In fact, I ended up removing the plastic cowl to get enough room to get my hands in to disconnect the clips.