Thread Page - Alfa Romeo Owners Club USA

2010-07-28 19:03:25

location of ac low pressure port on 1986 Spider

Bob Massaro
registered 2010-07-28
*

Compressor has two male connection ports on top, both with exactly the same caps, no markings. Which port is the low pressure? Nearest the right wheel or towards the engine? I have connectors and hoses but need to know which is which.

2010-08-01 12:13:53

location of ac low pressure port on 1986 Spider

Bill Unger
registered 2008-10-02
Florida First Coast Alfa Romeo Club *

The high pressure Shrader valve is marked by a “D” (delivery) on the top of the compressor (located towards the wheel well). The low pressure Shrader valve is marked by a “S” (supply) on the top of the compressor (located nearest the distributor.

If your A/C compressor is the original, the ports may be the "old" style (small size) and you may have to replace them with the "new" style (larger size). But there is very little room under the distributor to connect the "new" larger style couplers. So you may have to make an adapter to go between the compressor and your newer hoses.

If your A/C has been working fine and has lost enough pressure due to a small leak to keep from producing cold air, try charging with just a single small can of refrigerant and the hose that will come with the kit (available from Advance Auto, Auto Zone, etc.). Don't worry if the old system still has R12 ... the new R134a will not ruin it.

If your system is completely flat, you will need to recharge with 3 small cans of R134a to bring the pressure up to cool.

If your A/C compressor is not engaging the clutch, check the ground wire on the compressor .... it is very prone to shaking itself to death and losing ground. The compressor has rubber bushings in the mounts, and this ground wire is critical to making it work. Make up a new wire with round electrical connectors and put under a bolt on the front of the compressor and under the distributor pinch clamp bolt to complete the ground.

If your A/C compressor is working but will just not hold pressure, then you probably have a leak in one of the hoses ... they are very prone to rubbing against the rough welds of the body panels. You may be able to cut the hoses, insert a barbed joiner, and clamp the hoses with screw clamps. Cover the hoses with that plastic corrugated wiring loom that is available by the foot at any parts store to prevent future disappointments.

Carefully check the alignment of the plane between the A/C compressor clutch pulley and the main engine belt pulleys. If they are askew, you may eventually throw the belt or put undue strain on the A/C compressor clutch bearings. The bolts holding the mounting bracket to the engine block may be loose or missing (especially evident from loud clunking noises when you hit a bump as the bracket will be bouncing off of the top of the oil sump). Or the rubber mounting bushings may have disintegrated internally. You will then have to remove the A/C compressor and set everything straight again. Use red Loctite on the mounting bracket bolts to semi-permanently hold in place ... they are very prone to working their way loose.

Good luck!
Bill Unger, 1987 Spider Veloce

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