1970 K5 Blazer A/C questions

[BurnoutNova]

im in the middle of redoing the a/c on a 70 blazer at school for a friend. its all original, factory parts.

i belive its a frigidare R5? radial compressor... the sticker is uclear off capacity of refigerant. it says 3.25lbs in one spot and 4.25 in another... i think this one uses 3.25 and this same compressor was available on suburbans w rear air? am i on the right track?


i took off all the hoses and sent them to a local shop to put new ends on and new barier hose, because the only place i could find any parts for this was LMC, and i dont have time to wait for a week to get the parts. anyway does anyone know how much this 70 K5 needs for r-12 refrigerant and the oil capacity... ALLDATA doesnt go old enough and out service manuals are confusing at school. when i call the dealer in town they look in thier books forever and never give the right info.

[Blazer1970]

My '70 factory service manual says 3 lbs. 4 oz. R12, and 10 fluid oz. 525 viscosity compressor oil. The roof mounted Suburban system used the higher quantities as you speculated. The factory compressor was a Frigidaire 6 cylinder axial type - 12.6 cu. in. displacement.

[JimKshortstep4x4]

The system capacity for your Blazer is 3 lbs. 4 oz. for the R-12 refridgerant.
Full oil charge for a dry system is 10 oz., per truck manual.

If replacing components only, the following amounts of oil are to be added, per component: compressor, 7 oz, evaporator, 3 oz, condenser, 1 oz, receiver/drier, 1 oz.

The manual lists two different capacities for the oil, (10 oz and 11 oz). If you add the component additions up it comes out to more than 10 oz. In looking at other Chevrolet oil capacities, the oil charge is listed at 11 oz for similiar systems. We add 11 oz to dry systems.

Jim