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Procedure - 2004 S10 Blazer Compressor, Acc, OT Replacement

wgabriel10 on Mon September 20, 2010 8:44 PM User is offline

Year: 2004
Make: Chev
Model: S10 Blazer
Engine Size: 4.3L
Refrigerant Type: R134
Ambient Temp: na
Pressure Low: na
Pressure High: na

Inserted below is a procedure I created when replacing the a/c compressor, accumulator, and orifice tube in my 2004 S10 Blazer due to a failed compressor clutch. I thought I would post it in case it might help others. It can be modified to suit your own situation or other vehicles for that matter. I created it mainly to keep me from forgetting to do something in the process and it did help. I also had researched out the system to see what wrenches I needed for the various fittings. The original file also includes a recharging procedure -- my modified version of one posted in the Procedures section of the forum; however, I left that off of the text below.

And yea, the procedure was modified slightly during the actual work, so it is verified.

Also -- from what I found I can "back up" some posts I read on the forum about the GM accumulator outlet fitting being a weird size. It does not seem to relate to any practical SAE or metric size. This is why I ended up using an adjustable wrench on that one!

It was originally a MS Word file. Not finding a way to "attach" the Word file to a post on the forum, I converted it to a text file to post.

Use as you see fit for your own application.





(Assumes no indicated requirement for system flush, such as catastrophic compressor failure)


Turn a/c switch inside vehicle to OFF. Vehicle off.

Wear appropriate Personal Protective Equipment.

May be wise to disconnect negative battery cable for safety.

Remove a/c drive belt.

Clean-up outside of fittings, tubes, etc for dirt, etc.

NOTE - Before R134 removal, check that the HP cut-off switch (rear of compressor) you plan to use, if new, fits your Blazer's electrical connector. There are two types of connectors - a round "insulating shell" and an oval "insulating shell". Ensure plug and switch will mate together.

Remove old R134.


Disconnect cable connector from LP Cut-off Pressure Switch. Has push-button retainer.

Remove LP Cut-off Pressure Switch (cycling switch) from Accumulator.

Disconnect refrigerant fittings from Accumulator at Evaporator Outlet.
Evaporator side (Inlet) - Small = 1-1/16; Large = 32mm or 1-1/4
Compressor side (Outlet) - Small = Adjustable (28mm (sloppy)/27mm no-go); Large = 1-1/4

Bag open system refrigerant fittings for protection from dirt, etc. (Sandwich bag + tie, etc)

Remove Accumulator bracket screw on evaporator enclosure side and remove Accumulator. No need to mess with screw/bracket mount connected to Evaporator Inlet tubing run. (10mm socket)

Dump oil from Accumulator (Inlet mostly) and measure quantity. Quantity = ________oz.


Flip-up Accumulator bracket to gain more access to Evaporator Inlet fitting. Accumulator bracket will pivot on second bracket connection to Evaporator Inlet tubing towards front of vehicle.

Disconnect Evaporator Inlet fitting and bag.
Small = Adjustable or 20mm; Large = 15/16

Remove old Orifice Tube (needle nose pliers). Inspect for particulates, indicating need for system flush.

Install new Orifice Tube (White) with o-ring. Make sure OT is fully inserted. (Nylog)

Replace Evaporator Inlet fitting O-ring. (Nylog)

Re-connect Evaporator Inlet fitting. (Nylog)
Small = Adjustable or 20mm; Large = 15/16
Evaporator Tube to Evaporator Fitting 28 N-m/21 lb ft


Put same amount of Refrigerant Oil into new Accumulator Inlet port as was removed from original Accumulator plus 2 oz. See Replacement Oil Recommendations section about total oil.

Replace O-rings in Inlet and Outlet fittings. (Nylog)

Install new Accumulator in mounting bracket; Re-install but do not tighten bracket screw. (10mm)

Line up and re-connect Inlet fitting (first) and then Outlet fitting. (Nylog)
Evaporator side - Small = 1-1/16; Large = 32mm or 1-1/4
Compressor side - Small = Adjustable; Large = 1-1/4
Accumulator to Evaporator Fitting 28 N-m/21 lb ft
Compressor Suction Hose to Accumulator Fitting 48 N-m/35 lb ft

Tighten Accumulator bracket screw. (10mm)

Re-install LP Cut-off Pressure Switch. (Nylog)

Re-connect cable connector to Pressure Switch.


Remove hold-down fastener and move carburetor air duct assembly out of the way. Would be wise to put paper towel or rag over carburetor intake.

Remove Throttle Cable bracket to provide access to rear left compressor bolt. (10mm socket)

Disconnect Clutch power plug. Has retaining clips on both sides.

Remove suction/discharge header from compressor and bag. (13mm socket)

Disconnect HP Cut-off Pressure Switch cable connector (may be performed after removing compressor mounting bolts and moving compressor for better access). Has push-button retainer.

Remove Compressor mounting bolts and remove compressor. (13mm socket)

Dump oil from old Compressor and measure quantity. Quantity = ________oz

Remove HP cut-off pressure switch on rear of compressor if you plan to re-use it. See Note in Prerequisites/Preparation section. (C-ring pliers; be careful not to break pressure switch if to be re-used; do not use pliers on plastic insulating shell)


Check new compressor for oil charge. Drain oil if present and discard.

Install HP cut-off pressure switch in new compressor. (Nylog) (C-ring pliers)

Put same amount of Refrigerant Oil into new Compressor as was removed from original Compressor or 2 oz, whichever is greater. See Replacement Oil Recommendations section about total oil.

Tilt compressor "pulley-down" to let oil get to shaft seal.

Put compressor in place and re-connect HP cut-off pressure switch cable connector.

Mount new compressor. Use X-pattern for tightening bolts. Use Anti-Seize on bolts. (13mm socket)
A/C Compressor Mounting Bolts (4.3 L) 50 N-m/37 lb ft

Replace suction/discharge header seals. (Nylog)

Re-connect suction/discharge header. (13 mm socket)
Compressor Suction/Discharge Hose to Compressor Bolt 33 N-m/24 lb ft

Re-connect Compressor Clutch Power Plug

Rotate compressor by hand several revolutions to distribute oil.


Re-install Throttle Cable Bracket. (10mm socket)

Replace carburetor air duct assembly.

Re-install drive belt.

Re-connect negative battery cable, if it was disconnected.

Recharge system using recharging procedure. Ensure a/c system is turned off before beginning recharge procedure.



Accumulator Replacement - 60ml (2 oz) Add PAG equal to amount drained from old accumulator PLUS the 2 oz specified.

Compressor Replacement - 60ml (2 oz) Delphi service compressor is shipped dry. (Note 1)

Condenser Replacement - 30ml (1 oz) (Note 1)

Evaporator Replacement - 90ml (3 oz) (Note 1)

Total System PAG Oil Capacity (HT6) = 236ml (8 oz)

Note 1 -- If more than the specified amount of PAG oil is drained from a component, add the equal amount drained into the new component. Otherwise, add the amount indicated.


TRB on Mon September 20, 2010 9:00 PM User is offlineView users profile

Note. The old switch is replaced with the newer style which comes with a plug that is spliced in the OEM wiring.


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