66 Monaco Wagon A/C Resurrection

[TxDon]

The car is mobile again! The new condenser has been mounted, radiator and cooling system back together, fluids in and it runs. I think the new points were needed, it started up so quickly I was surprised. I measured for and ordered the barrier hose, one additional fitting and a spare set of O-rings from Cold Hose, which I hope to have within a week. My Grandson is visiting next week so I hope to get back to it the week after.

 

[BIGBARNEYCARS]

The car is mobile again! The new condenser has been mounted, radiator and cooling system back together, fluids in and it runs. I think the new points were needed, it started up so quickly I was surprised. I measured for and ordered the barrier hose, one additional fitting and a spare set of O-rings from Cold Hose, which I hope to have within a week. My Grandson is visiting next week so I hope to get back to it the week after.

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Well done Don, and it lookz good too. Now where'z that thumbz up Icon, Jer

 

[TxDon]

Spent time with my grandson last week and did little on the car but I did take it for a short ride. Freakout time, it made a loud rumbling / grinding noise whenever I accelerated! I go into diagnostic mode - check all the fluids, check the belt clearances, check all the bolts, but still the noise is there when I took it out again this morning. I'm thinking the worst, then I noticed the clamp holding the smaller power steering hose to the inner fender is loose. I tightened the screw and drove it again - no noise at all!

I got all my hose and fittings so I will be getting back to it later in the week.

 

[TxDon]

It's been a busy week but I finally got some time yesterday. I reinstalled the original liquid line and big low side line on the evaporator with the new expansion valve and temperature cycling switch. Both lines are teed into the lines for the rear A/C unit. I also used a spare fitting and some old hose to try out the hydraulic crimper - very easy to use and looks like it works. Now I start making the new lines.

 

[TxDon]

I tackled the main low side line yesterday. In order to hook up with the rear A/C I needed to route over the engine like the factory metal pipe, including a kick-up to clear the throttle / trans linkage. I tried doing it with a single hose but that big #12 would not bend enough, so I used a 90 degree coupler and two shorter pieces of hose. I connected to the compressor with a side exit hardline from Nostalgic A/C and a #10/#12 stepup fitting. I also found a carb adaptor to fit the stock air cleaner which clears everything. Need to get some black zip-ties instead of the white but it came out OK.

 

[TxDon]

I am now pretty much done with installation. The high side and liquid lines are in and connected to the condenser. I ran the high side line through the factory grommet under the battery and connected it to the compressor with the other hardline from the Nostalgic A/C kit. The liquid line runs up over the top of the condenser, looks a little weird but should work. The only unconnected fittings are at the dryer which is mounted in the oem location. I made up a wiring harness connecting the thermo cycling switch to the pressure switch then back to the compressor, all 14 gauge wiring. First time I ever used the "static cling" non-adhesive tape, it was easy to use and looks factory. Tomorrow I plan to connect the dryer up and pull a vacuum - first big hurdle, fingers will be crossed.

 

[TxDon]

The new system has been successfully evacuated and recharged. I hooked up the last two fittings at the dryer on Monday and set up my gauges and vacuum pump. This was my first attempt using the quick connect high and low pieces so I didn't know you had to tighten them up to open the valves so when I turned the pump on it immediately pulled a 30! Luckily I read the instructions a little better and tightened the connectors down, doing it right it took longer but I still pegged the needle and the vacuum held.
One thing I have noticed all through this project is how many different opinions there are on how to do things like flushing, evacuating and charging. Between instruction sheets, online articles, forum posts and You-Tube videos it is easy to get confused!
I probably vacuumed that system a total of at least 2 hours because of my screw-ups, including about 20 minutes yesterday before charging. The charging process went well, the compressor started up about 10 minutes after opening the first can of R134. It took about an hour and a half and used 28 ounces to fill to 50psi low / 300psi high. The worst part was that summer is here in Texas with 95 degrees ambient so it was probably about 120 in my garage and I felt like a drowned rat! I still have to replace the grille and do some cleanup but I'm looking forward to driving it.

 

[steveh]

To help keep your high pressures in check and gain efficiencies.. You make want to help the air flow through the condenser with some baffles to connect the condenser to the rad support. This way the rad fan pulls the air though the condenser and not around it.

Good work overall
Steve

 

[TxDon]

This job is officially done, the car is all back together and I have driven it 3 times in 90 degree weather. I am very happy, both front and rear units work great, and it will freeze you out in the Max A/C setting! I am still knocking on wood and keeping fingers crossed regarding the long term but I definitely appreciate all those who recommended the conversion route.

 

[LocuMob]

Thank you, Don! I'll be using this as my reference when I get around to restoring my Monaco 500, the only car I'll have A/C in. You've made a very clear and easy to follow guide for me, and hopefully for others as well!

 

[TxDon]

Barring any problems or questions I will probably not be adding any more to this thread. I did want to finish up with some cost and time comments in case anyone contemplating a similar project may be interested.

Time: I started thinking about restoring vs. converting last year when my oem system crapped out. Like I always do I dithered around for quite a while, I did a LOT of research including other detailed threads previously mentioned. I finally made the decision to do the modern upgrade conversion the end of March this year and started buying tools and parts. The actual teardown began on May 1 and it was done and working on July 12, roughly 10 weeks. I am 70 years old and retired so I could work on this whenever I wanted to but for the same two reasons I took it slow and easy. My typical work "day" was probably 3 to 4 hours with at least a day off in between work days, sometimes a lot more than that. For other chronologically challenged folks I will say this was a pretty easy job with very little under-car time and more brain work than brute force.

Tools: While I already owned all the basic mechanic's tools I had never done my own A/C work before so I did invest in quite a bit - Gauge set, vacuum pump, flush gun, hydraulic hose crimper, can taps, and other misc. I bought because I wanted them for future use but most tools can be rented or borrowed, I am not including tools in my cost for the project.

Cost: All of the parts including R134 refrigerant and oil cost $975.00. I did not have to farm out any work so my labor was free. I chose to buy the parts piecemeal rather than get an underhood kit mostly because of my need to connect to the rear system, none of the kits followed the routing I wanted. I paid extra for a genuine Sanden compressor versus all the Chinese knockoffs and I used the Bouchillon compressor mounts which were expensive but well worth it. The compressor, all fittings and all hose came from Cold Hose which is actually Air Parts in Ocala, FL. Their prices beat everyone elses and all is USA made. The condenser came from Nostalgic A/C mostly because they had the right size and I bought their compressor hardline kit because no one else offered it.

I hope this will help, please come back with any questions.

 

[TxDon]

I'm back to this thread after almost two years. My converted A/C system worked very well up until recently, it was still cooling but I noticed it was not keeping up the first few 80 degree days this spring so I figured it had lost some refrigerant. Today was hot and humid, about 85 degrees so I figured it was a good time to top it off. I hooked up my gauges and popped a new can of R-134. When I first started it up and turned the A/c on both low and high sides read low. I closed the hookup valve on the high side and opened the low side gauge valve, the low gauge shot up to 100 and the high side was at about 145. Recommended numbers at 85 degrees are 45-55 low and 225-250 high. I let it run for awhile thinking it would stabilize but after about 20 minutes the low side was at 110 and the high had only gone up to 150. I shut it down and disconnected everything and am naturally pissed. I will be researching this but would appreciate any thoughts from the experts out there.

 

[Davea Lux]

I'm back to this thread after almost two years. My converted A/C system worked very well up until recently, it was still cooling but I noticed it was not keeping up the first few 80 degree days this spring so I figured it had lost some refrigerant. Today was hot and humid, about 85 degrees so I figured it was a good time to top it off. I hooked up my gauges and popped a new can of R-134. When I first started it up and turned the A/c on both low and high sides read low. I closed the hookup valve on the high side and opened the low side gauge valve, the low gauge shot up to 100 and the high side was at about 145. Recommended numbers at 85 degrees are 45-55 low and 225-250 high. I let it run for awhile thinking it would stabilize but after about 20 minutes the low side was at 110 and the high had only gone up to 150. I shut it down and disconnected everything and am naturally pissed. I will be researching this but would appreciate any thoughts from the experts out there.

A first glance, I would say the low side is very high, sounds like the system is over charged. Before bleeding off any refrigerant, run the engine for about 2-3 min at 2000 rpms. That way, you should be getting enough air flow to properly cycle the system. If the numbers are still high, it is probably overcharged, but I am not sure why the high side numbers did not also come up as well because an overcharged system will usually also have very high numbers on the high side. With the system running, feel the back side of the expansion valve, it should be cold with some some wet condensation present. If the valve is hot, it is probably not working properly. Is the compressor running steadily? If the system is over/undercharged, the pressure valve will usually cause the compressor to short cycle which might also explain your pressure numbers. With only a 45 lb differential between the high and low side, this system and not going to cool very well. Check these things and report back.

Dave

 

[TxDon]

A first glance, I would say the low side is very high, sounds like the system is over charged. Before bleeding off any refrigerant, run the engine for about 2-3 min at 2000 rpms. That way, you should be getting enough air flow to properly cycle the system. If the numbers are still high, it is probably overcharged, but I am not sure why the high side numbers did not also come up as well because an overcharged system will usually also have very high numbers on the high side. With the system running, feel the back side of the expansion valve, it should be cold with some some wet condensation present. If the valve is hot, it is probably not working properly. Is the compressor running steadily? If the system is over/undercharged, the pressure valve will usually cause the compressor to short cycle which might also explain your pressure numbers. With only a 45 lb differential between the high and low side, this system and not going to cool very well. Check these things and report back.

Dave

Thanks Dave. When I charged the system two years ago the numbers were perfect on both sides and the system has worked very well up to about a month ago so I don't see how it could all of a sudden be overcharged. During my attempt today it did not accept much if any new refrigerant. The compressor is running steadily, I will check the expansion valve and let you know.

 

[TxDon]

I took the car out for a ride today under cooler conditions, about 72 degrees and overcast. With those conditions it felt better in the car but at the end of the trip it still was not freezing me out as it had in the past. With it idling in the driveway I checked the dash output at both regular cool and max ac on high blower, kind of seemed like it was cooler on the regular setting than max but it was not dramatically different. I had the rear unit also on high and its output was noticeably cooler that the dash vents, this unit is recirculate only with its own expansion valve. Under the hood the dash system expansion valve was cold with condensation on the bottom. The smaller line from the compressor to the condenser (high side?) was very hot and the larger line was cool. Any other thoughts?

 

[TxDon]

Photo of the two compressor lines mentioned above.

 

[Davea Lux]

Photo of the two compressor lines mentioned above.

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Nice clean looking installation. If you have a cold line coming back to the compressor, the system would appear to be working. It is normal for the line to the condenser to be hot. On the max air setting the fresh air door is closed, so the system is also on recirculate on the front unit. Check you heater hoses in and out, you might be pulling hot air off the heater core, this will overload the cooling capacity of the evaporator core on the front unit if the heater valve is stuck open.

Dave

 

[TxDon]

Nice clean looking installation. If you have a cold line coming back to the compressor, the system would appear to be working. It is normal for the line to the condenser to be hot. On the max air setting the fresh air door is closed, so the system is also on recirculate on the front unit. Check you heater hoses in and out, you might be pulling hot air off the heater core, this will overload the cooling capacity of the evaporator core on the front unit if the heater valve is stuck open.

Dave

If the heater valve is stuck open what should I feel on the heater hoses versus it being closed? and why would this affect my gauge readings?

 

[Davea Lux]

If the heater valve is stuck open what should I feel on the heater hoses versus it being closed? and why would this affect my gauge readings?

If the heat valve is stuck open, both heater hoses will be hot from circulating coolant. If it is closed, only one hose will be hot. A question, when you took the pressure readings, were both the front and rear units set to high fan? If the rear unit was off, that would cause a jump in the pressure reading on the low side and a drop in pressure on the high side. From you photos, I do not see a filter/dryer assembly, I assume there must be one as the filter/dryer also serves as a receiver for excess refrigerant. Most filter/dryer assemblies have a sight glass on the top, do you see lots of bubbles in the sight glass? This means the refrigerant is boiling coming off the condenser, either from low charge or insufficient cooling air going thru the condenser.

Dave

 

[TxDon]

If the heat valve is stuck open, both heater hoses will be hot from circulating coolant. If it is closed, only one hose will be hot. A question, when you took the pressure readings, were both the front and rear units set to high fan? If the rear unit was off, that would cause a jump in the pressure reading on the low side and a drop in pressure on the high side. From you photos, I do not see a filter/dryer assembly, I assume there must be one as the filter/dryer also serves as a receiver for excess refrigerant. Most filter/dryer assemblies have a sight glass on the top, do you see lots of bubbles in the sight glass? This means the refrigerant is boiling coming off the condenser, either from low charge or insufficient cooling air going thru the condenser.

Dave

Thanks, I'll check the hoses, I'm also going to verify all the mode doors are working properly. The rear unit on these cars is always on when the front unit is activated, the only control is fan speed, but yes I had it on full blast. I did replace the filter dryer keeping it in the stock location and adding a pressure switch that was not stock. The sight glass is painted over. There is no obstruction for airflow to the condenser.