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Airco issues

Halbie

Halbie

New member
Joined
Aug 23, 2025
Today had an airco inspection. The guy showed me with blue light and glasses that mij condensor has some leaking and there are some trails of leakage on the pump. The airco still works but feels a little less efficient when asking power from the engine ( accalerating) or when stationary. The airco was filled a little more than a year ago the last time.
Is replacing the condensor with a new one (Nissans) and fill it up again sensible?
Any thoughts? 940 lpt auto ecc 96. The condensor looks warn
 
If there's evidence of leaks at both the condenser and pump it'd be a good idea to replace both. You don't want to have the system filled just to do it again in 6 months when the pump gives.
 
Netherlands 🇳🇱. Leakage is in the cooling fans parts. I will see how long she will be cooling. After that have the system drained (professionally)and replace condensor and compressor. Any suggestions on conpressor?
 
Update on this topic. The airco actually works fine. The uphill / acceleration issue turns out to be related to a faulty non-return valve in the vacuum lines most likely. The hack is fairly straight forward; decouple the yellow vacuum line from the most front pump at the driver site (you can reach this by removing the upper cover in the foothold at the driver side. Plug the yellow line and the airco works full time and very good.

Next step is to locate and replace the valve. Sofar I have not been able to locate it. Any suggestions?
 
Halbie said:
Update on this topic. The airco actually works fine. The uphill / acceleration issue turns out to be related to a faulty non-return valve in the vacuum lines most likely. The hack is fairly straight forward; decouple the yellow vacuum line from the most front pump at the driver site (you can reach this by removing the upper cover in the foothold at the driver side. Plug the yellow line and the airco works full time and very good.

Next step is to locate and replace the valve. Sofar I have not been able to locate it. Any suggestions?
Click to expand...

Can you show a picture of this?

There is this thread about the common issue on the 740 of the dash vents cutting out during boost:

DET17

Thread '90 745 HVAC system overhaul'

A general question for those of you with extensive experience/knowledge of the 7/9 machines.

I've brought my 90 745 back to a good status..... however one sore spot that will need my attention is the under dash HVAC, I believe made by HARRISON, a GM division. As my compressor is now singing its death song, I'll be replacing it along with both hoses, orifice tube, accumulator, and flushing the evaporator & condenser. I know my way around AC systems pretty well, having several of these vehicles previously.

One area I've not deeply dived into yet, the Harrison assembly...
 
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