Automotive Air Conditioning Information Forum

Volvo V70 1997 no high side port and other issues

R134a

Getting the wagon ready for my kid as an after college car. It was their high school car.

No high side port to connect a gauge to. What's best way to add a high side port?

The system was not engaging due to low pressure. Bypassed low pressure switch to get refrigerant in. Then it seems to turn off due to high pressure.

Thoughts/hints?

Thanks.

Also can someone confirm refrigerant capacity? Online sources like a Mahle guide spec a range - 750–850g / 26.5-30oz / which is 2.2-2.5 12oz cans

I added about 1/2 can / 6 OZ in the above post/situation.

andrew vanis wrote: ↑Wed Jul 10, 2024 9:59 am No high side port to connect a gauge to. What's best way to add a high side port?

Leave it to Volvo to do something bizarre and difficult for MVAC technicians to deal with.

On some of these cars (unsure about the '97 V70 Wagon), you'll need to unscrew the high-side pressure sensor and attach a suitable service-port adapter (or hook-up directly if you have a red hose with a 1/4" flare female fitting on one end) onto the Schrader valve fitting where the sensor was located. While testing the system, be sure to provide plenty of airflow through the condenser using an auxiliary fan, if necessary.

andrew vanis wrote: ↑Wed Jul 10, 2024 10:43 am Also can someone confirm refrigerant capacity? Online sources like a Mahle guide spec a range - 750–850g / 26.5-30oz / which is 2.2-2.5 12oz cans

The specifications that I have for your Wagon are as follows: 750-850 grams (26.5-30.0 ounces net weight) of R-134a, and 200 milliliters (6.75 fluid ounces) of PAG-46, unless you have an under-hood decal with specs that differ. In that instance, the decal takes precedence.

JohnHere wrote: ↑Wed Jul 10, 2024 12:48 pm

andrew vanis wrote: ↑Wed Jul 10, 2024 9:59 am No high side port to connect a gauge to. What's best way to add a high side port?

Leave it to Volvo to do something bizarre and difficult for MVAC technicians to deal with.

On some of these cars (unsure about the '97 V70 Wagon), you'll need to unscrew the high-side pressure sensor and attach a suitable service-port adapter (or hook-up directly if you have a red hose with a 1/4" flare female fitting on one end) onto the Schrader valve fitting where the sensor was located. While testing the system, be sure to provide plenty of airflow through the condenser using an auxiliary fan, if necessary.

andrew vanis wrote: ↑Wed Jul 10, 2024 10:43 am Also can someone confirm refrigerant capacity? Online sources like a Mahle guide spec a range - 750–850g / 26.5-30oz / which is 2.2-2.5 12oz cans

The specifications that I have for your Wagon are as follows: 750-850 grams (26.5-30.0 ounces net weight) of R-134a, and 200 milliliters (6.75 fluid ounces) of PAG-46, unless you have an under-hood decal with specs that differ. In that instance, the decal takes precedence.

That's what I also found on some of the Volvo forums and the challenge with that is apparently the system does not work without the high side switch connected.

My gauges are quarter inch fittings..... How about using a quarter inch tee like used in HVAC where one side is female and two sides are male and screw that onto the quarter inch male fitting on them vehicle pipe.. And then connect the switch to one of the mail legs and then either my 1/4 inch gauge directly or put on a quarter inch to high side 134 adapter.

andrew vanis wrote: ↑Wed Jul 10, 2024 1:05 pm That's what I also found on some of the Volvo forums and the challenge with that is apparently the system does not work without the high side switch connected.
My gauges are quarter inch fittings..... How about using a quarter inch tee like used in HVAC where one side is female and two sides are male and screw that onto the quarter inch male fitting on them vehicle pipe.. And then connect the switch to one of the mail legs and then either my 1/4 inch gauge directly or put on a quarter inch to high side 134 adapter.

The "tee" idea sounds good. No obvious reason that the system shouldn't work with the HS switch receiving pressure in that way.

andrew vanis wrote: ↑Wed Jul 10, 2024 10:43 am Also can someone confirm refrigerant capacity? Online sources like a Mahle guide spec a range - 750–850g / 26.5-30oz / which is 2.2-2.5 12oz cans

AllData has the same.

JohnHere wrote: ↑Wed Jul 10, 2024 1:20 pm

andrew vanis wrote: ↑Wed Jul 10, 2024 1:05 pm That's what I also found on some of the Volvo forums and the challenge with that is apparently the system does not work without the high side switch connected.
My gauges are quarter inch fittings..... How about using a quarter inch tee like used in HVAC where one side is female and two sides are male and screw that onto the quarter inch male fitting on them vehicle pipe.. And then connect the switch to one of the mail legs and then either my 1/4 inch gauge directly or put on a quarter inch to high side 134 adapter.

The "tee" idea sounds good. No obvious reason that the system shouldn't work with the HS switch receiving pressure in that way.

so the fitting seems like a smaller than 1/2" ACME siince the 1/2Acme fittings/adapters I have are too big. (I can't seem to attach an image) this link may be able to show a close up I took

click on this link for CLOSEUP
https://photos.google.com/share/AF1QipO ... VUQ19yd2tn

This link discusses it as an ACME fitting
https://www.matthewsvolvosite.com/forum ... %20Fitting

This shows a (not so good) picture of it

This link discusses that the high pressure switch hasa volt output/pressure(kPa) readout.
https://www.matthewsvolvosite.com/forum ... 66#p437266
Here's apic from that post

I wonder if it would be easier to splice in a port fitting into one of the high side hoses.

What are the chances the hoses are a standard barrier or reduced barrier diameter?....And how could I check ideally without cutting one

andrew vanis wrote: ↑Wed Jul 10, 2024 10:29 pm I wonder if it would be easier to splice in a port fitting into one of the high side hoses.
What are the chances the hoses are a standard barrier or reduced barrier diameter?....And how could I check ideally without cutting one

It's probably worth a call to the folks at Cold Hose in Ocala, Florida. They specialize in all kinds of fittings, and I'm sure they could advise you further. Most likely, they can also tell you which type of hose you have.