zytra

Hi

I need some advice. I have a 90 pickup 3VZE.
I found that my TVV had a vacuum leak, so bought a replacement.

It is located on the coolant manifold between and firewall. Took the hood for easy access. I had modified a 19mm socket to clear the ports (mainly to reinstall the new one as the bad one has a broken port anyway.

The damn thing is stuck. Been on it for over an hour, before starting I bathed the valve in liquid wrench. Using 14" ratchet for some decent lever.

I got one complete turn off. The first 1:4 turn was easy (did it with a 8" ratchet) but then it got just so damn hard. I don't want to break the thing and something tells me there is something up. These TVV are tapered thread so tge first quarter turn should have been the toughest.

I don't know maybe I'm overthinking it and it just needs some more muscle power.

Have you guys ever been in a situation like this? I did break an ECT once while tightening and I sure dont want to repeat that.

Edit: i also tried my small cordless impact and the valve didnt move.

Thanks
Steve

zytra

Guess posting here did the trick. Started on it again slow and steady, one click at a time and it got better slowly.
Threada looks pretty bad, corroded probably.

millball

Looks like it carried a little of the aluminum away with it.

You should'nt have to put the new one in super-tight.

I'd use some sort of paste type pipe dope, rather than teflon tape.

I don't suppose you have a BSPT tap to chase the threads with??

zytra

Thanks
I havent put the new one in yet.
I could find some place to get a tap, any idea what thread it is?

My new tvv is the same aisin as the original one, which comes with blue sealant already in place.

Should I be concern about burrs falling in if I can put my hands on the right tap?

Thanks again for the quick response

millball

The thread format is gonna be 'British standard pipe, tapered', otherwise known as BSPT, not American NPT pipe thread.

It's probably gonna be either 1/4" BSPT, or 3/8" BSPT; you have got the old part for a sample when looking for the correct tap.

I would'nt worry too much about burrs, just put a good dose of grease in the tap flutes and the greaase will pick up most of the chaff.

zytra

Thanks! Any idea where I can find those on a sunday? I think HF only carries NPT. And never really looked at home depot/lowes.

millball

I've found some BSPT stuff at Ace Hardware before.

Not all Aces' carry the same stuff though. Good luck!!

zytra

Thanks worth a try
If not mcmaster tomorrow

zytra

Hi

I was able to fix it. Kind of a pain. The only tap I found har a .525 square shank and none of my tap wrenches would work... Either not big enough or not long enough to reach behind engine/firewall.

Ended up machining a smaller shank on the tap with the CNC took me a long time to go through the hardened steel of the tap but got it done regardless.

Worth the idle doesn't feel as rough and my vacuum reading is now past 20". (It was 14-15" before)

Worth the time and effort

Thanks again