Halfway through a pcv service on my 95 850 (NA). Ready to swing the intake manifold out of the way and saw that I need to disconnect the large diameter (3/8 inch or so) hard pipe coming out of the EGR valve. It was rusty so I applied several shots of Parts Breaker to the connection. Nut turned easily and began to unscrew and unscrew and unscrew. It won't disconnect! It re-tightens fine. Could I cut (maybe with a pipe cutter out of my plumbing box) maybe 2 or 3 inches out of the middle of that pipe and splice in a 12" loop of high pressure hose, maybe use 2 hose clamps per end? I dont think this hard pipe will come out- bloody thing...

Any advice would be helpfull, like to get the old girl back on the road by Monday. THANKS!! Dave

 

It's not pressure that matters. If that is the solid metal line it's exhaust and you'd need a high temperature hose. Not sure they make one that will handle the temperature.
If you're not using "PB Blaster" for a penetrating lube I'd try that.
Any chance you are getting the nut loose but the tube is seized inside the EGR valve?

 

kiss- well ive soaked the nut with PB very well, thought id do that since the nut was quite rusty. I guess it could be that the pipe is frozen to the egr valve, but the nut never seems to fully come off the threads, like the nut won't come off. seems like I should be able to slide the nut up the pipe a bit eventually, but it wont no matter how many times I unscrew it. Kind bummed cause I'm so close to getting my mitts on that oil seperator.

 

I haven't pulled mine (EGR or "PCV" box) so I'm not sure. The fact that the nut tightens back up makes me think you're getting the nut loose but I hope someone who has pulled the EGR off will chime in. I tried to find some pictures of the end of the tube that goes to or into the EGR but no luck. I've seen where the tube fits into an EGR similar to a compression fitting but it's just a slip fit and a shoulder in the tube under the nut is what seats and seals it. I keep thinking the part that might slip into the EGR is seized but I don't know a Volvo's ??
I do have the whole IPD PCV kit waiting for some inspiration to dig in. So I'm curious how it comes apart as I have an EGR hanging under there too.
This is one of those situations where a picture of the end of that pipe would be sooooooooo very helpful.
Can you apply a torch to it ?? Besides heating it up and gently trying to twist the EGR off the pipe you can also respray it with the PB when it's cooling down as that will help "pull" it in as it cools.

 

I have taken two of those apart because these T-5R's have them. The 1st one was like you are experiencing. I just turned and turned and turned and it did not seem to pull off. So I got something in there and pulled the pipe loose, may have pryed it loose. I thought it would never go back on because of how hard it was to come off but I was wrong. It went back on pretty easy after I got it linned up.

 

Well I managed to wiggle that nut till she finally backed off completely. but I did discover the flared end of the tube is stuck in the egr valve. I've been soaking it down in PB, will again tomorrow morning and noon. I havent tried the torch, kinda saving that as my last resort- lots of rubber stuff down there. I have all of the bolts out of the manifold (should've left the bottom ones on I know) thought maybe by wiggling the manifold a little I could break it loose. Nothin. Got my fingers crossed on the PB but I usually think of that for rusted stuff. Dont want to mess up the flare on that pipe by getting too wild with the hammer.

It always looks soooooo easy on paper on those clean, shiny engines...

Dave

 

Had the IDENTICAL problem on my 94 850 NA. Long story short HEAT did the trick! I hammered, twisted, pulled and hammered some more but no luck. Heat was my last resort. It took about 2 minutes. Of course don't stay in one place too long. Sweep the flame back and forth. Then maybe straight on the EGR threads for about 2 seconds then back and forth etc. I had a leather mallet, I smacked it and bingo, off it came. Went back on with no problem. Hope this helps!

 

That's why I try my best to include "what might happen" and "tools needed" when I do instructions. Also, the long boring threads usually have mention of these types of problems.

If you have time, you may want to add your 2 cents to the PCV thread.

Hope it's loose soon so you can get that finished up.