Fleetwood Brougham V8-252 4.1L (1985)
Compressor Clutch: All Technical Service Bulletins
A/C - Buzz/Rattle/Moaning Noise
Bulletin No. T
84-102
File In Group
1
Number
17
Date
Aug. '84
SUBJECT:
AIR CONDITIONING CLUTCH DRIVER NOISE
MODELS AFFECTED: 1985 DEVILLES AND FLEETWOODS EQUIPPED WITH HT4100 ENGINE
Some 1985 Devilles and Fleetwoods equipped with the HT4100 engine may experience a rattle, buzz or moaning noise which is evident only at certain
engine speeds (1650 and 1100 RPM) with the air conditioning compressor engaged. This noise may be caused by vibration of the A/C compressor clutch
driver. The following procedure should be followed to properly diagnose and correct this condition.
1.
Start car. Set Electronic Climate Control as follows: 60~F, AUTO mode, LO fan. Allow car to warm up by idling for 3-4 minutes.
2.
Enter ECM diagnostics as described on page 1C-16 of the 1985 FWD Deville and Fleetwood Service Information Manual. Enter parameter P.1.1,
which will display engine RPM.
3.
A. With transaxle in "PARK", increase engine speed to exactly 1650 RPM. Hold engine at this RPM for 15 seconds and listen for a
metallic-type rattle, buzz or moaning noise.
B.
Decrease engine speed to 1500 RPM and listen for an increase or decrease in noise level.
4.
A. With transaxle in "PARK", run engine at 1100 RPM. Hold engine at this RPM for 15 seconds and listen for a metallic-type rattle, buzz or
moaning noise.
B.
Decrease engine speed to 950 RPM and listen for an increase or decrease in noise level.
If a noise is noticed at either 1650 RPM or 1100 RPM, but not when engine speed is reduced, the A/C compressor clutch driver should be replaced with
damped service clutch driver kit, P/N 2724325. This kit should be installed using the following procedure.
1.
Remove engine splash shield from inside right front wheelhouse by disengaging the four retainers. Remove drive belt from compressor pulley.
2.
Remove A/C compressor clutch driver dust cover Torx screws and remove cover. Discard the dust cover since it cannot be used with the new
clutch driver.
3.
Remove clutch driver from compressor using tool J-33013. Refer to 1985 FWD Deville and Fleetwood Service Information Manual, page 1D2-2,
for procedure.
4.
Remove splash shield from beneath A/C compressor.
5.
Loosen or remove compressor mounting bolts as required to move compressor to provide clearance for damped clutch driver installation.
6.
Thoroughly clean any grease or oil film from clutch face on pulley.
7.
Position new clutch driver on compressor shaft. Be sure that the key and keyway are properly aligned.
8.
Install compressor mounting bolts which were loosened or removed in step 5.
9.
Using tool J-33013, install new clutch driver on compressor shaft. Refer to 1985 FWD Deville and Fleetwood Service Information Manual, page
1D2-2, for procedure. When using this procedure, substitute special tool J-25030 (clutch hub holding tool) for tool J-33027.
NOTICE:
The dust cover and attaching screws included with clutch driver kit P/N 2724325 cannot be used on Cadillac applications and should
be discarded. Do not attempt to install any dust cover on this clutch driver.
10.
Reinstall the drive belt on the A/C compressor pulley.
11.
With the engine running, cycle the A/C compressor "OFF" and "ON" several times to burnish the clutch surface and ensure proper operation.
For warranty purposes, use Operation Number D4240 at .5 hour.