1989 K1500 Silverado A/C question

[ellis479]

I went to check the A/C coolant level on my 1989 Silverado, 5.7L and the port for the gauge is all rusted. What causes this, and can I use W/D 40 or oil to remove the rust? Thanks Ellis479

[j cAT]

Originally Posted by ellis479

I went to check the A/C coolant level on my 1989 Silverado, 5.7L and the port for the gauge is all rusted. What causes this, and can I use W/D 40 or oil to remove the rust? Thanks Ellis479

the ac system uses aluminum lines and plastic caps so rust ? does not compute .

if a metal steel cap was used on the aluminum then I would say your screwed on this one. these metals eat away at each other .