E 350 Van L6-300 4.9L VIN E 1-bbl (1982)
Evaporator Drain Tube: All Technical Service Bulletins
A/C - Condensate Leakage Into Passenger Compartment
Article No. 86-9-14
A/C CONDENSATE LEAKS INTO PASSENGER COMPARTMENT - VEHICLES BUILT PRIOR TO MARCH 1986
LIGHT TRUCK 1975-86 ECONOLINE
When a vehicle is operated under conditions of extremely high humidity with the Function Selector Lever in the "NORM A/C" position and the blower
switch in "HI", some evaporator condensate, instead of draining out of the vehicle, is being blown through the ducts and registers and into the passenger
compartment.
Condensate from the evaporator core exceeds the amount which can be drawn off through the drain tube in the evaporator case. As a result, the excess
condensate can be pulled away from the drain tube and picked up in the air stream created by the blower motor. It is then expelled through the A/C
registers.
To correct the condition, one or more of the following service procedures should be initiated in the sequence listed. They are to be initiated on a
customer complaint basis. Vehicles built prior to March, 1984 will continue to be serviced, as required, by all of the procedures covered in TSB
85-11-16 in addition to the procedures provided in this article. Complaints requiring service on vehicles built from March, 1984 to March, 1986 will be
handled by following the sequence of procedures in this article.
NOTE:
Operation of the blower at a lower speed than HI will allow accumulated condensate to drain out the drain tube. Therefore, operation of the
blower below HI where possible, or periodic reduction of the blower speed from HI, will significantly reduce moisture accumulation. Also,
when comfort will allow, operation of the air conditioner in MAX A/C rather than NORM A/C will reduce condensate accumulation by
reducing the humidity entering the vehicle.
SERVICE PROCEDURE:
1.
The sealing and leak checking procedures previously published in TSB 85-11-16, dated 6/3/85, must have already been performed, or should now
be performed before proceeding with the added service operations covered in this article.
2.
Replace the evaporator check valve and drain tube assembly (including the 90~ formed drain tube and check valve) with a new check valve and
drain tube assembly.
3.
If replacement of the evaporator drain tube assembly does not correct the condensate leak, add a separate drain hole in the blower housing as
outlined under "Addition of Drain to Blower, Housing".
4.
If the condition still persists, install a locally fabricated moisture coalescer screen as outlined under "Addition of Coalescer Screen to Evaporator
Assembly".
Sealing and Leak Checking Per TSB 85-11-16
1.
Using TSB 85-11-16 as a guide, confirm that the sealing operations described have been effectively accomplished.
2.
If sealing is missing, apply it to the surfaces indicated in the TSB.
