broken "bimetal valve assembly" from the EGR system (3 Viewers)

[txgringo]

In my efforts to resolve a P0401 code, I remove my upper intake manifold and all the associated lines and cleaned everything up, replaced the VSV, replaced all hoses and vacuum lines. It wasn't until I went to put everything back in that I realized I had broken off one of the nipples on the bimetal valve assembly (toyota 25820-13020). These are not cheap and not in stock at the local dealer, but fortunately a local friend of mine loaned me his from a spare engine until my used replacement arrives later this week.

Now I'm faced with the challenge of replacing this little turd without disassembling half of the freaking engine. So I have 2 questions on this:

1. Does anyone have any experience pulling this without taking off the lower intake manifold? (I have the upper off still; trying to keep this simple). I'm about to try to modify a 19mm box wrench to try and fit into this spot. Cutting it down to make a stubby flare wrench.
   
   
2. What's the issue with bypassing this and just looping a short piece of vacuum hose from the two tubes coming off the bottom of the intake (see circled area in diagram below)?

 

[txgringo]

Update:

I wanted to get this thing put back together today, so I proceeded with chopping down a wrench to try and make a stubby. Because the hex head of this valve is slightly recessed in the side of the block AND because it's installed with probably 70ft/lbs of torque, the stubby wrench was NOT the answer.

I decided that the only way to get this thing done was to modify a deep socket to allow it to fit over the plastic nipples and make contact with the hex head on the valve. This worked beautifully and I am now proceeding with reassembly of the intake.

Pics below of the socket modification in case anyone else runs into this in the future. (NOTE: the valve is actually in the socket backwards in the first picture, but the concept is the same.)

 

[tech_dog]

How bad a job was this? I've got my upper manifold off and was thinking about swapping out the bimetal valve while I'm in.

Thanks for any info,

T.

 

[Malleus]

While the TVV is a PITA (being a part of Jimmy Carter's attempt to save the planet), it's not difficult to install. The statement the it's "installed with probably 70ft/lbs of torque" is grossly inaccurate. The correct installation torque is 22-lb·ft, which is easily managed with an open end wrench.

The problem is that it's installed in a coolant circuit galley, and therefore the thread is sealed with RTV (Three Bond 1311, if it was installed per the service manual), so removing it without removing the intake is problematic.

However, if you're TVV is malfunctioning, and you should check it according to the procedures on page EG-311 and EG-180, your intake is probably nasty to, so just pull it off and clean it. The gaskets are cheap and your engien will thank you for it.

If you don't have a copy of the service manual, download one from the Resources forum. It's free. We really need to rename that forum "Please move along, nothing to see here".

 

[tech_dog]

I have my throttle body and the upper intake manifold off for other maintenance, so I decided to replace my TVV / bimetal valve as preventative maintenance.

I bought the tool below from Lisle 19mm Line Socket (12770) - https://www.jbtools.com/lisle-line-socket-19mm-12770/ and it worked perfectly. I used a long socket extension and a breaker bar, applied about 50 ft-lbs, and it gave up with no heat required. I'm not sure if it did any good because of the sealant, but I used PB blaster 5 days and 1 day before removal.

One more box checked off, and it was surprisingly easy. You don't need the lower manifold off, and you could probably get it done with the upper manifold and TB on.

T.