AeroNautical Posted June 12, 2018 Share Posted June 12, 2018 I've done an OBD1 HO conversion on my 88 MJ 4.0, and since the dash had to come out anyway, I added all the necessary A/C components. Stock routing for the 93 XJ it all came out of. Brand new components. I can get a vacuum on the system with no problem, -30 IN HG for hours without the needle moving. Oil was in the system, so I started the truck, turned the compressor on and it runs beautifully. I start adding my first can of R134a ( I did the R12 to 134 conversion) and about 30 seconds into adding the can the high side fitting ruptures and shoots freon and PAG everywhere. The system itself is fully intact, it was the high side quick disconnect that blew. I replaced the O-Ring in the fitting and tried it again. Same issue, this time with a rag around the fitting, that oil is some nasty stuff. Obviously the high side is building pressure, it seems too much. Ideas? Thanks Link to comment Share on other sites More sharing options...
MuddFoot Posted June 12, 2018 Share Posted June 12, 2018 Sounds like it's not clipping in all the way. I just redid mine on my 95 obd 1 mj and don't remember any quick disconnect on it. Maybe their is. I don't remember I'll. Look tomorrow. Sent from my Z982 using Tapatalk Link to comment Share on other sites More sharing options...
dvitha Posted June 12, 2018 Share Posted June 12, 2018 The system should be able to handle as much as 400 psi with out leaking or blowing out. if the high side is leaking out of quick connect you best need to change the stem inside, since it seems to be bad. You could have a bad fitting all together. I have came across cheap china parts that mold is not right. We make all our hoses in shop and they are rated at 1000psi. The high side needs to hold as much as 400 plus psi. a rag is not going to hold any type of pressure. The quick connect I think he means is the 134a high side port. Link to comment Share on other sites More sharing options...
AeroNautical Posted June 12, 2018 Author Share Posted June 12, 2018 The rag was just to contain the mess if it happened again. The high side quick connect doesnt actually blow off the nipple when it happens, it blows out around the o ring. I'm using an r12 to 134 conversion kit, and the high and low side ports from the r12 are just adapted to the 134a q/c. Ill see if I can't get a picture up a bit later. Link to comment Share on other sites More sharing options...
AZJeff Posted June 13, 2018 Share Posted June 13, 2018 I would check to make sure you have good adapter fittings first of all, as others have suggested. About the only other way you could have high pressure is either a blockage or too much refrigerant oil. This may be important because evacuation does nothing to get rid of old refrigerant oil, and if you reused any old parts, who knows how much oil may be in those parts from the past. You said "brand new components", so I assume this means new condenser and accumulator. Those are important to a conversion, since the old R12 oil tends to settle in those two components. If you replaced those, then the R12 oil (no matter how much) isn't in the equation there. Link to comment Share on other sites More sharing options...
MJCARENA Posted June 13, 2018 Share Posted June 13, 2018 Do you have the valve on the compressor screwed in all the way blocking off the condenser ? Should be in the mid position. Link to comment Share on other sites More sharing options...
Griff04 Posted June 13, 2018 Share Posted June 13, 2018 If you have this type of service valve as seen below then go to this post to see correct positioning when servicing the system: Link to comment Share on other sites More sharing options...
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