I have never worked on a R134a system. I'm a fairly skilled home mechanic having 40+ years experience on various cars and have an Airframe and Powerplant license for aircraft work. That two year training course covered air conditioning systems and I've made good use of the info.

With that in mind, as I understand it R134a systems should use the crimped beadlock fittings. Now I might try to experiment using the standard or barbed fittings but only on the low pressure return line. I will not recommend that approach to anyone else.

When I installed the inline tap on my R12 system, I used regular screw clamps, but wrapped the clamping area on the OD of the hose with a turn or two of electrical tape. I did this to keep the clamps from cutting into the hose. Heatshrink tubing would also be a choice of mine. If you use the closed crimp type clamps found elsewhere on your Volvo this would not be needed.

Good luck,

Tatra Mike
San Diego, California

1985 244 "Alfsen" (wife's car - the good one)
1984 245 "Buster" (the kid's car, now sold)
1985 245 "Cosmo" (parts car, sold off for move to WA)
1985 245 "Daisy" (back seat down, full of tools, the work truck)
1985 245 "Earl (CA vehicle 'retirement' program)