AC - Any reason I can't install low side fitting on high - PeachParts Mercedes-Benz Forum

300SD81 · #1 06-03-2007, 07:24 PM

I cannot find a coupler for the high side port anywhere cheaply. I'm wondering if I could swap the high side R134a adapter for a low side fitting and have it stand up to the pressure. I plan on doing all my own work so I don't care if its compatible with standard stuff or if a shop will service it.. I know better than to connect a can or something to the high side, so nothing to worry about there. I'm going to cut a charging hose and use it to connect a gauge to measure high side pressure. The hose says its rated up to 2000psi.

Pete Geither · #2 06-03-2007, 07:55 PM

This borders on trying to fix a seat belt. Find the money to do the job right or put up with the heat. JMHO.

300SD81 · #3 06-03-2007, 07:58 PM

Hey.. R12 used the same fittings for both sides.. And it'd make it obvious theres NOT R134a in there...

dukegrad98 · #4 06-03-2007, 09:40 PM

Quote:

Originally Posted by 300SD81

I know better than to connect a can or something to the high side, so nothing to worry about there.

Maybe nothing to worry about to you, but I'm worried about the next owner or the idiot at the quickie-lube who hooks up to this and blows his hand off. No offense, but I'd say it's got bad idea / liability written all over it. Chalk this one up to being a job that should be done right.

Cheers, John

300SD81 · #5 06-03-2007, 09:45 PM

Anyone know where I can get a high side connector cheap/free then? Anyone have a broken hose? I plan on cutting it and clamping to a gauge..

Actually.. will a can actually explode at around 200psi? I'm going to be using a hydrocarbon refrigerant anyway, so lower pressures than R134a... I put some butane in a syringe once and was able to condense it by pushing really hard by hand..

Knightrider966 · #6 06-03-2007, 09:50 PM

Quote:

Originally Posted by 300SD81

I cannot find a coupler for the high side port anywhere cheaply. I'm wondering if I could swap the high side R134a adapter for a low side fitting and have it stand up to the pressure. I plan on doing all my own work so I don't care if its compatible with standard stuff or if a shop will service it.. I know better than to connect a can or something to the high side, so nothing to worry about there. I'm going to cut a charging hose and use it to connect a gauge to measure high side pressure. The hose says its rated up to 2000psi.

NO, you cannot swap them out for good reason. I fail to see how you cannot get the proper equipment for a reasonable price. I got a Stewart warner manifold gauge set for about $100.00 with tax! You can charge your system through the manifold gauges with the third hose attachment so there is no need to jury-rig it and risk getting someone hurt. I had a neighbor do what you propose and he was tired one night and forgot momentarily what he was doing and nearly lost an eye when the container exploded and sent shrapnel all over the neighborhood! Just do it right and avoid problems like legal issues for one.

300SD81 · #7 06-03-2007, 09:52 PM

Quote:

Originally Posted by Knightrider966

NO, you cannot swap them out for good reason. I fail to see how you cannot get the proper equipment for a reasonable price. I got a Stewart warner manifold gauge set for about $100.00 with tax! You can charge your system through the manifold gauges with the third hose attachment so there is no need to jury-rig it and risk getting someone hurt. I had a neighbor do what you propose and he was tired one night and forgot momentarily what he was doing and nearly lost an eye when the container exploded and sent shrapnel all over the neighborhood! Just do it right and avoid problems like legal issues for one.

$100 :X I'm already skipping meals and have no spending money for the next 4 months to pay for a compressor... I'm not going to be doing this, but will be going hunting for a broken high side manifold gauge hose to clamp to my gauge..

Knightrider966 · #8 06-03-2007, 10:28 PM

Quote:

Originally Posted by 300SD81

$100 :X I'm already skipping meals and have no spending money for the next 4 months to pay for a compressor... I'm not going to be doing this, but will be going hunting for a broken high side manifold gauge hose to clamp to my gauge..

Well if all your doing is testing your pressure, then remove the R134 fitting and just use the older style R12. those are still easy and cheap to get.

deerefanatic · #9 06-04-2007, 07:15 AM

Yah really, just take em off and use the stock R12 fittings..... Gauges can be had VERY cheaply on ebay..... Hoses and all.......

There's nothing like having the real thing (manifold gauge set...)

300SD81 · #10 06-04-2007, 09:43 AM

Ok, I figured out how to do it super cheap... The retrofit kit that was on my car allows the R12 fitting to keep its valve core.. So all I have to do is temporarily swap the low fitting over to the high side and then either leave it off or put it back on the low...

Matt L · #11 06-04-2007, 11:42 AM

Quote:

Originally Posted by 300SD81

I'm going to be using a hydrocarbon refrigerant anyway, so lower pressures than R134a...

You realize that the R134a connectors are not to be used in a system originally holding R12 but now using something other than 134a, right?

I also note that you are asking to borrow a gauge set in the other forum. I'll tell you something that you don't want to hear: you can't use the same gauge set for 134a and hydrocarbons (or anything else). So if I were to lend you my gauges, they would then be useless to me. No thanks.

Do it right or not at all.

michael cole · #12 06-04-2007, 01:33 PM

Quote:

Originally Posted by Matt L

You realize that the R134a connectors are not to be used in a system originally holding R12 but now using something other than 134a, right?

I also note that you are asking to borrow a gauge set in the other forum. I'll tell you something that you don't want to hear: you can't use the same gauge set for 134a and hydrocarbons (or anything else). So if I were to lend you my gauges, they would then be useless to me. No thanks.

Do it right or not at all.

This i do not understand.does r134 somehow contaminate the guages.rendering them useless???

Matt L · #13 06-04-2007, 02:20 PM

Quote:

Manifold gauges allow technicians to diagnose system problems and to charge, recover, and/or recycle refrigerant. A standard fitting may be used at the end of the hoses attached to the manifold gauges, but unique fittings must be permanently attached at the ends of the hoses that attach to vehicle air conditioning systems and recovery or recycling equipment. Similarly, refrigerant identifiers may be used with multiple refrigerants. The connection between the identifier or similar service equipment and the service hose may be standardized and work with multiple hoses. For each refrigerant, however, the user must attach a hose to the identifier that has a fitting unique to that refrigerant permanently attached to the end going to the vehicle. Adapters for one refrigerant may not be attached to end 2 and then removed and replaced with the fitting for a different refrigerant. The guiding principle is that once attached to a hose, the fitting is permanent and is not removed.

http://www.epa.gov/ozone/snap/refrigerants/macssubs.html

Matt L · #14 06-04-2007, 02:21 PM

It appears that I misread the regulations, in that this applies only to recovery or recycling equipment.

Still, you would need to completely remove the hydrocarbons from the gauge before using it on a 134a system.

300SD81 · #15 06-04-2007, 04:29 PM

Quote:

Originally Posted by Matt L

I also note that you are asking to borrow a gauge set in the other forum. I'll tell you something that you don't want to hear: you can't use the same gauge set for 134a and hydrocarbons (or anything else). So if I were to lend you my gauges, they would then be useless to me. No thanks.

I was only planning to use the manifold to connect the vacuum pump, since my charging hoses are all very short. I would not contaminate someone elses gauges...