Seville V8-252 4.1L (1982)
Valve Body: Customer Interest
A/T - Delayed Engagement, Loss of Pump Prime
Bulletin No. T 85-80 File in Group 7
Number
120
Corp. Ref. No. 8057401
Date
May '85
SUBJECT:
DELAYED ENGAGEMENT - THM 325, THM 325-4L
MODELS AFFECTED: 1979-1985 ELDORADO 1980-1985 SEVILLE
This bulletin supersedes Serviceman Bulletin T84-38A, Group 7, #93 (originally listed as T84-59, #97), which should be destroyed.
Some 1979 through 1985 Cadillacs equipped with either a THM 325 or THM 325-4L transmission may experience an intermittent condition of delayed
transmission engagement when shifting from Park and/or Neutral to Drive and/or Reverse upon initial start-up after being parked for several hours. This
condition may be caused by a loss of pump prime.
FIGURE 1A AND B
Previously, a soft plastic pump intake check valve had been included in service filter assemblies which assisted in maintaining pump prime. A revised
filter was released in the 1985 model year for both production and service stock, with improved filtering capabilities, which does not contain a check
valve. Therefore, when servicing any of the above listed vehicles for delayed transmission engagement, it is necessary to install a pump intake cheek
valve and sleeve assembly P/N 8635971 (refer to Figure 1B) following the listed service procedure.
Service Procedure
1.
Verify proper fluid level and condition with transmission in park, at normal operating temperatures, engine running. Correct as necessary and
retest. If delayed engagement is still present, proceed to step 2.
2.
Remove the transmission oil pan and filter as outlined in Section 7A of the appropriate Service Information Manual. Make sure that the filter to
case O-ring is also removed from the pump intake hole in the transmission case.
