The top nut on proportioning valve is weeping slightly. I suspect it's just the seal, but it looks like it has been tightened at some point by the PO so I am reluctant to tighten the nut now, without the parts on hand, because you know what will happen.

I called Volvo for a seal kit and the guy didn't even know what a proportioning valve was. He wants me to drive over there and look at book.

There doesn't seem to be anything in FAQ on the valve itself but I know I read a write up here once. Can anyone find it?

Or there a part number for the valve I can use to find new seals or is it better just to replace the whole thing with the one from my donor car. (Way easier to replace a top seal than the whole hard-to-reach-valve)

BTW no warning lights or brake problem other than the initial low brake fluid which pointed me to the problem in the first place.

If it looks similar to this...

From Art Benstein's site


...it's called a "junction block" or distribution manifold. Any weeping from the screw-in switch at the top means internal o-ring failure. Normally the brake fluid should never reach that area. See the text in the lower left corner of Art's photo.

The proportioning valve (if present) is inline to each rear brake.
--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

If it looks similar to this...

From Art Benstein's site


...it's called a "junction block" or distribution manifold. Any weeping from the screw-in switch at the top means internal o-ring failure. Normally the brake fluid should never reach that area.

The proportioning valve (if present) is inline to each rear brake.
--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

Thanks. Yep, I mean no, you're right, apparently its called the junction block, I'm not sure it has the pressure switch since there is no switch.

here's a very bad photo in the dark but as you can see, the weeping is at the large shiny nut at the top of the body, not where the brake line comes out.




the whole thing looks like this

http://www.thefind.com/cars/info-brake-line-junction-block.


now that I have a proper name and part number I will be a more informed customer tomorrow with the dealer.

Thanks

I was faced with the same trouble identifying the part. Many mechanics called it a brake portioning valve. The dealer calls it a 'reducing valve,' and VADIS calls it a 'reducing valve.' The Volvo dealer system prints 'reducing valve' on the invoice with the part number I provided.

Hi, I bought a new one last week, Volvo calls it a reducing valve. It is part number 3546634. I paid $291 for it, which is fine as I understand the seals are a pain to replace and most of the unit has to come off to see where the problem is.

Once everything is off, the car is out of commission until the valve is back on. If it's bad, I may as well replace it with a new one.

My understanding is that the lines may also crack/be cracked while replacing the valve.

If you find a source for the seals and lines, let me know as I will need to replace these too.

Hope this helps.

There are no seals where the lines connect, they are flare fittings. I doubt the lines will break or crack. There is a risk of cross threading when reconnecting if you are careless.
--
David Hunter

I torqued it pretty good today and it didn't budge so you may be right, somewhere in it's life a PO cross threaded the nut. The brake lines are OK and didn't bend or crack. The local Volvo guy nixed the idea of using my 1994 parts car block, said it wasn't worth taking the chance.

Either way we had a little family emergency today and the car has a new home tonight. I'm not thrilled about it, but it was one of those greater good moral questions.

Funny how these things work out.

Thanks to all.

Hi,

I read your other post, now I know where it ended up.

Now what is a PO?

Gus

In this context, a previous or prior owner.

Hi,

I have two questions:

What is a PO?

Does your car have a new home because you had an accident or is it being repaired?

Gus