Sanity check: LSPV Leaks

[gorbilax]

I'm just about at my wit's end here with this and was hoping to get a sanity check from the mud brain trust - the LSPV brake line connections are M10 inverted flare, correct? There is nothing magical about the flare nuts or the flare technique for these particular connections, right?

I'm replacing some brake lines on my 80 series and just installed a new OEM LSPV (old one was frozen with rust). All of my flares are perfect and leak free except for the two going into the LSPV from up front. I've redone them twice and both always leak. This is not my first rodeo - I've done dozens of flares on various vehicles over the years with this flare tool and never had issues, so this has me questioning my sanity. My flares visually appear the same as even the OEM Toyota lines. I'm using 3/16" cupronickel line and double/inverted flares with M10 steel flare nuts from NAPA. If anyone has a better recommendation on nuts, let me know.

And yes, I know I may be setting myself up for a chorus of *just delete the LSPV, I did it and now everything works great!* but I am too concerned about insurance liability issues, so I'm really trying to leave it in place.

 

[Pascoscout]

Deleted, missed that you have a new lspv.

 

[gorbilax]

Ended up finally solving this issue. I'm surprised in the history of 'mud, this has never come up before. Hopefully I can share some knowledge here and save those who come after me some trouble.

There are indeed two different kinds of flare nuts on the 80 series (or perhaps there are three - I think I've read the ABS pump uses ISO bubble) - some connections are the "regular" M10x1.0 flare nut available at auto parts stores - these seem to be the connections that go into flexible hoses. Other connections, including the ones going into the LSPV use what Toyota calls "Flare B". These nuts have a smooth non-threaded section on the bottom (the one on the right below). You can order the nuts from Toyota as 96311-11000. After redoing my flares with the OEM "Flare B" nuts, everything fits perfectly with zero leaks.

 

[Malleus]

Those piloted fittings were a work around, I think. They work, but you have to know about them or you'll never get the system to work.

This should be a FAQ.