2003 xc70 exhaust flex pipe, part number?

[Blacklab467]

It's unfortunately become time to address a failing flex pipe on my car, I've inspected the rest of the exhaust components and all seem pretty good. The muffler may need replacement in the future but I've identified with certainty that the flex pipe is failing.
Does anyone have a part number of a good quality flex pipe of the correct dimensions that they've used successfully? I plan on cutting the old one out and welding a new one on the bench but am mostly concerned with sourcing a quality replacement.
Also, how co-operative are the brass nuts with being removed from the turbo flange, any tips on getting these out without snapping the stud off?
Thanks in advance!

[jonesg]

did mine 2 weeks ago, you need to make a wooden jig to hold aligment before chopping the flex pipe off.
i removed the 3 nuts with a milwaukee 12v 3/8 stubby impact, they were no problem at all.
buy new copper coloured nuts with gaskets at fcp. new nuts are swaged , they will not vibrate loose.
look up the torque, it was fairly low, around 25 fig newton meters or so.... but look it up.

Bought the flex pipe at O'Reiley auto parts, $43.
Turbo end of the volvo pipe is 2 1/2 but the cat end is smaller, so I butt welded the front part and did a slip fit at the rear, it is a sloppy fit but I shimmed it with scrap cut-offs and welded the whole thing up.
this is the best pipe with concertina inner liner same as volvo, . 2 1/2 x 8 inch . overall length is more but you'll cut to fit.

https://www.oreillyauto.com/detail/c/ni ... ic0/525008

worst part was trying to unplug the o2 sensors, i gave up and cut the wires, if you cut the wires be sure to do it where you can resolder and heat shrink them back again. then i wrapped the repaired section with gorilla tape.

[jonesg]

a reminder, after welding ,
cover the ends of the pipe with duct tape and inject 15 psi compressed air, then use soapy water to find leaks in the new welds. I found 3 leaks and welded em up.

[Blacklab467]

Excellent thank you! Did you have much trouble with the flange nuts at the front? Did they come off without getting destroyed? I have bad luck with anything threaded on exhaust systems!

[jonesg]

they should make the rear hardware out of the same material because the front nuts didn't corrode at all.
The 3 nuts come off with no problem.

I used this hardware kit,
https://www.fcpeuro.com/Volvo-parts/V70 ... =8642449KT

because my rear flange (lower end) was rusted out the supplied gasket was slightly too big,
I ended up using a slightly smaller one , $9 from amazon or autozone etc, its a common size.

FEL-PRO 61451 Exhaust Pipe Gasket.


Exhaust hanger extractor tool was a god send, wd40 to spray the rubber first.

Lisle 38350 Exhaust Hanger Removal Pliers.
https://www.fcpeuro.com/Volvo-parts/V70 ... le%2038350

[Blacklab467]

And 8 inches is adequate or should I get a 10 inch and trim it as necessary? I thought yours came up a little short in the video?

[jonesg]

And 8 inches is adequate or should I get a 10 inch and trim it as necessary? I thought yours came up a little short in the video?

8 inch refers to the flex part only,
the aluminized steel pipe on each end adds 4 more inches to the 8.
so the overall length is 12 inches.
it doesn't matter if it comes up a bit shorter, the aft cat pipe has 2 inches of play in the rubber hangers.

using C25/argon gas it mig welded very easy with no burn thru's.
i was told to spray the welds with manifold paint to stop rust ......... but forgot.
if you can weld ( i can't) , you will find it a breeze, i had lots of feedack from the experts at weldingweb.
i practiced on scrap exh pipe all summer. If you're using flux core wire, good luck with that.