BMW 3 Series (1991-1999) A/C Condenser, Vacuum & Re-Charge




Replace the A/C Condenser, Vacuum, and Re-Charge the A/C on an E36 (1991-1999) 3 Series BMW

Works For:
1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999 BMW 3 Series Models
BMW 3 Series Includes:  316, 318, 320, 323, 325, 328, 330 and M3 .

Source: BimmerForums

E36 (1993+) A/C Condenser Replacement & System Recharging Procedure

DISCLAIMER:
It is illegal to vent R-134a in to the atmosphere. If your car has residual R-134a in the system, you must take the car in to have it professionally evacuated. Legalities aside, R-134a is toxic! Wear gloves and eye protection when dealing with this stuff. Note, this procedure is for R-134a cars only! This means 93+ E36s. I am not responsible for anything. Below is an account of how I did it and it may not work for you …

Ok, disclaimers aside – this job is easy. I mean really easy. Just be careful. There are a lot of steps though …

SITUATION: 
I bought my ’93 E36 with a busted condenser as diagnosed by a dealer. Didn’t care at the time, Sandy Hago has great weather (especially where I live) . Anyway, I saw a condenser on ebay and decided to pick it up. A couple months later, I was ready …

DIAGNOSIS: 
If your system has pressure in it, get it evacuated professionally. There are many shops that will do this and even tell you where your leak is (they use a die and a black light). My car had no pressure in it, so this step didn’t apply to me. 

STUFF YOU’LL NEED:
1. A/C condenser (used, oem doesn’t really matter that much). Expect to pay less than $150. Dealer price is $450+

2. A/C receiver/dryer (oem). Ebay has ‘em for about $45. Dealer price is $125+.
3. Gaskets. Refer to the following picture for which ones. Caution! The ETK is wrong (at least for my car) on this. The dealer was also wrong. Overbuy if you must. About $40 (I know, what a rip). I ended up getting 4 #6s and 4 8s.

 

4. Manifold Gauge set for R-134a. Should have a blue gauge and hose (low pressure), red gauge and hose (hi pressure) and yellow hose (refrigerant supply/vacuum). About $75-$100.
5. Vacuum pump (oil based preferred). Don’t know where to get one. Maybe it can be rented. I borrowed one from a friend. They run for $250 I hear.
6. 3 cans (12oz) of R-134a and 1 can (8.5oz) of refrigerant oil. Available at any parts store. Total cost = $40.
7. Usual set of tools – Philips screwdrivers, hex sockets, ratchet.

8. six pack. I hate American beer, Rolling Rock is an exception though.

Total (if you buy everything) = $(150+45+40+100+250+40+10) = ~ $640.
Total (if you know someone with a pump and manifold (or rent)) = $(150+45+40+40+10)= ~ $290
Total (if you’re lucky like me ) = $(85+$40+$25+$30+10) = $190 (ebay – condenser/receiver-dryer, friend had the pump and manifold, gaskets – I know the parts guy at the dealership, kragen sale on R-134a and oil)
Total (dealership) = $1000+ !!!

PROCEDURE:
1. Check for existing pressure
a. Lift the hood and hang the manifold on the hood latch (roughly eye level).

b. Make sure that all valves (hi, low and ref/vac) are closed. 
c. Plug the low side (blue) in to the low side port. The ports are of different sizes, so you really can’t go wrong here.

d. If you see pressure (not vacuum), take it to a shop to get it evacuated.
e. If you see vacuum, you may not have a leak (or a very slow one). End here and just either recharge with refrigerant or add some stop-leak type additive.

2. Do a leak test (only if you have zero vacuum)
a. With the set up in step 1, connect the high side as well. 
b. Plug in your vacuum and turn it on based on pump instructions. 
c. Open the ref/vac valve and the low side and high side valves. 
d. You should see a vacuum starting to form (the needle on the gauge will go below zero). 
e. Let it run for 5mins, and then shut off the blue valve, the red valve, the ref/vac valve and the pump. 
f. Come back after 5mins and check if you’ve lost any vacuum. If you have, you need to find the leak. Take it to a shop. The steps below are only if your leak is in the condenser unit.
3. Raise the front end of the car up on ramps. You need to do this because the condenser comes out from the bottom of the car. Chock the rear wheels and use your handbrake. Safety disclaimer applies here.
4. Remove the bumper
a. Using a flat head screwdriver with tape on the ends, carefully remove the trim pieces as indicated. The longer of the two trim pieces that wraps around the side of the bumper is first pried from the front and then “pulled” forward. It’ll come out easily. If you’re putting too much force, get a beer and try again … ‘cause you’re about to bust something.


b. Go under the car and remove 8 screws (mine were hex 8mm) from under the left and right brake ducts. Maybe you’re missing some, I don’t care – just think and remove. 
c. Remove the brake ducts from the bumper.
d. Remove the fogs. Don’t just pull the connector! Once that bumper comes off and you set it down, the last thing you want is some neighbor kid coming and kicking your bumper around just to scratch/damage your $100 fogs! Ask me how I know!
e. Remove one screw on each side in the front wheel well (left and right side). Look at the picture.

f. Remove the four hex nuts (13mm) in the front under the trim pieces you removed earlier. The bumper is about to come off!
g. Slide off the bumper carefully. The splash guards in the front wheel wells may need to be tortured a bit (you’ll know what I mean). Once you’re done, you should have something like this.

5. Remove the plastic shroud covering your radiator. Four screws (hex 8mm I think) and two plastic push expander thingys. 

6. Remove the two screws holding your condenser in. Different years may have different procedures here. Just pick up a Bentley.
7. Remove the fours hex screws (8mm) holding the auxiliary fan. Don’t let it fall to the ground! Remove the wiring harness and set this thing aside. 


 

8. Remove the plastic shroud behind the auxiliary fan. A bit tricky here. There are two hex screws you should be able to see through the kidney grills. Use an extension to get to these ones. 

9. Remove the splash guard (4 philips screws for me) under the auxiliary fan. 
10. Remove the plastic shroud.

11. Remove the A/C lines to the left of the condenser. These are allen screws. They may be a bit tight. Once you unscrew them, plug the lines with something to prevent anything from getting in. 

12. Maneuver things a bit and pull the condenser out of the car from underneath. Make sure your new condenser/used/oem one has the same mounting points (visually you’ll see this). My 93 condenser looked quite different from the one I picked up from ebay but the mounting points were the same – so I didn’t care.

13. Put new gaskets on the pipes leading to the condenser. Use gasket #8 for the pipe leading to the receiver/dryer and gasket #6 for the pipe leading to the compressor.
14. Remove the AC lines at the firewall where you plug in your manifold. Replace both gaskets with gasket #6 (For my car, the ETK indicates to use gasket #7. This was WRONG. Even the dealer didn’t have this right). Re-attach the AC lines.
15. Remove the AC lines at the compressor. Replace them with gasket #6 for the line leading from the firewall to the compressor and gasket #8 for the line from the compressor to the condenser. 
16. Put in your new condenser. Installation was the opposite of removal. Re-attach the AC lines.
17. Replace the Receiver/Dryer
a. Whenever you replace any AC component, you must replace the receiver dryer since it has been exposed to air. Do this last as you want to minimize it’s exposure to air.
b. The Receiver/Dryer is located behind the right headlight. There are two 8mm hex bolts holding it in. 
c. Remove the AC lines first and replace the gaskets with gasket #8 (for both). 
d. Remove the old receiver/dryer and replace with the new one. Re-attach.
e. Open the plugs on the new receiver/dryer and quickly re-attach the AC lines.
18. I replaced all my gaskets in the engine bay. I did not go thru the trouble of opening up the dash and removing the expansion valve or the evap. Do whatever you want. You need 4 gasket #6s and 4 gasket #8s.
19. Re-install/Re-attach everything back. Installation is the opposite of removal.
20. Re-test leak: repeat step 2. If you’ve done everything correctly, you shouldn’t lose vacuum at all. Congratulations!

Re-charging procedure:
1. Make sure there’s enough oil in the vacuum pump.

2. Turn on the pump, open the red and blue and yellow valves. 
3. Run the pump for at least 30mins! I ran mine for an hour. This will get rid of air of course and any other moisture in the system.
4. Wear gloves and eye protection. 
5. Wear gloves and eye protection.
6. Wear gloves and eye protection!
7. Shut off all valves and then the pump (this may differ depending upon the pump instructions – just follow those). You should read about 30Hg of vacuum. 
8. Connect the can of oil (8.5 oz) to the ref. line on the manifold. Hold it upside-down and open the low valve and the ref. line valve and the valve on the can itself. NEVER charge from the high side. 
9. The system pressure should increase and your can of oil will empty out (almost empty out). Shake it a little bit to “help” it.
10. Close all valves and remove the oil can from the ref. line.
11. Turn on the car, turn on the A/C and put the blower on its lowest setting. Let the car idle for 5mins so that pressures equalize thru the entire system.
12. Turn your blower on hi. Connect a can of refrigerant to the ref. line on the manifold and open its valve. Open the yellow and blue (low side) valves on the manifold. NEVER charge from the high side!
13. The system pressure will rise and the can will empty out. It will also get very cold!
14. Check your vents, the air should be getting colder. Good job!
15. Once the can is empty (shake it if you must), shut all valves and repeat step 12 with the next can. My car used about 7oz of oil and 2.5 cans of ref.
16. Once done, shut all valves. Turn off the car. Carefully remove the lines. The red line (high side) will have some pressure in it. Keep those goggles and gloves on!
17. Take the car for a spin, you’re done!

 





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