Reconstructing the A/C system on my car.Need some advice please..
When I converted My car to V8 I threw a lot of "no longer needed stuff " away. A few of those items (A/C hoses etc) are now being replaced. Can any one tell me what size the fittings are,.. for the A/C evaporator connections. I am using a GM condenser and compressor, and I have already found some new hoses for them (first two items on list below )

I am going to have the other two hoses fabricated, but I do not know what sizes I will need at the connections to the evaporator. Can anyone enlighten me about the sizes I need?

This is one area I do not have much useful experience to work with,..so live and learn... I will probably use the AC a few times a year for cooling (Seattle) but would like to have the climate control functioning properly, so AC has to work.

I plan on using 134

GM compressor to the GM condenser hose
GM condenser to Jag drier hose
* Jag drier to JAG expansion valve (at evaporator) hose nut size
* JAG expansion valve to compressor hose nut size

The last 2 items are my concern. I plan on taking my drawing / info to a shop that makes hydraulic hoses. Thanks

 

I have found a few times now going to a hydraulic shop or "TPE Hose Dr" my local is called, it is easy for them to make up what you need and not too expensive. Saves a lot of running around, research or waiting for the wrong part to arrive.

 

When I did my V8 conversion, I used the OEM compressor which I mounted in the area of where the GM air pump was located.(top of the engine, driver side) I am still using the Jaguar OEM condenser. I installed a new Jaguar Drier and expansion valve,and connected them using the OEM hoses. I charged the system with R134a.
The AC system was cold enough for Florida.
However, after about a month, I realized that the system was not cooling enough. I was losing the refrigerant.
The refrigerant was weeping through the actual hose body. Under a UV light I could see the yellow dye all along the hose.
I resolved the issue by having new hoses made up using the original ends. I was told that the molecular structure of R134a is different from R12, hence the reason for the weeping. The new hoses resolved the issues.
It has been over 18 months since the hose refit and the AC is blowing nice and cold.
I believe that Roger did his AC conversion using GM parts so he would be the guru on this topic.

 

I always have new hoses made up at the local Hose Man shop or at my great AC shop. Or the R134 will escape through the old hoses. New green O rings are required as well as the proper oil and a new drier. Change the expansion valve for one setup for R134 or you will have to adjust the screw on the one setup for R12 and that is hit or miss to get the proper flow.

 

Just in case: Do you know/have the part # for the Expansion valve that is set up for R134?
I had to do the adjustment on mine because the flow was poor. Fortunately I think I got the adjustment just right because the AC is nice and cold.
If I were to ask the parts guys in my area, all I will get is a blank stare.

 

Thanks guys,

Since posting this thread a few days ago,.. I have stumbled upon Andrew's stuff on matching a Jaguar evaporator to a GM system. His method is slick ...using some Jaguar (modified) hoses and fittings, only requires one new hose to be fabricated ( low side hose,.evaporator to compressor) I plan on buying new "everything" that is compatible with 134a.

Thanks Roger - for the heads up re: green washers/seals.

In the JTR manual,.. they recommend using a muffler in the AC system... thoughts?
Also on another matter.. this is for the guys using a GM V8 TBI engine.. What was your solution for the coolant when you turn off the heat. Did you use a bypass valve?
Reason I ask is,..
GM uses a system of adjustable heater doors to control heat in cabin ( on GM cars) and a constant flow of coolant through the heater core..a coolant outlet is at back of intake manifold. Coolant flows from intake manifold to heater core and from heater core to the water pump. Coolant is always circulating =TBI is happy.. No high operating temps when heater is off.
Coolant still circulates without restriction. Adjustable flaps /doors control amount of heat.

Jaguar uses a (vacuum) shut off valve to stop the coolant from going through the heater core ..Fine with the Jag plumbing/engine. In the Jaguar system, when the heat is turned off - the vacuum controlled shut off valve simply stops the coolant from passing through the heater core.

But with the Jag heater OFF (no flow) and using a "TBI engine" the coolant now stops flowing through the heater core and now no coolant is flowing through the return hose running from heater to water pump. And if the engine is cold, and thermostat closed.. could that be a problem ?
I am thinking ...maybe.. On my TBI I have been running a hose that bypassed the heater and dumped into the heater return provisionn on the radiator (didn't need a heater for the time I was testing the installation. This is one of the areas I wanted to address - heat control) so I took out the Jag vacuum heater valve and replaced it with a vacuum controlled GM heater bypass valve. At this time the Jag is in pieces - doing stuff to it - getting ready for summer so I can not test the theory... got to wondering what others in same situation have done. Anything?