A/C - Condensate Leaks Into Passenger Compartment
Article No. 86-23-14
A/C CONDENSATE LEAKS INTO PASSENGER COMPARTMENT OR DISCHARGES FROM THE INSTRUMENT PANEL REGISTERS
LIGHT TRUCK 1975-87 ECONOLINE
Condensate may leak from the blower motor area or be expelled through the A/C registers during high temperature/high humidity conditions when the system is operated in Norm A/C and high blower.
In these cases, condensate collects in the temperature blend door area and leaks out the seams of the blower case and/or becomes airborne and is expelled through the A/C registers.
Check to assure that the evaporator housing has been sealed and the straight condensate drain tube has been installed as outlined in this article. Then, procure and install a new venturi tube and deflector in the evaporator assembly using the following service procedure.
SERVICE PROCEDURE
A/C Condensate Leaks Into Passenger Compartment - Vehicles Built Prior To March, 1986
Due to improper condensate drainage, water can accumulate in the bottom of the temperature blend door frame assembly and spill into the blower housing. If this condition occurs, insufficient sealing at the blower housing to evaporator housing flange and at the blower scroll cover to blower housing may allow leakage into the passenger compartment from these areas.
An accumulation of water in the blower housing may result in water being blown through the register ducts and register outlets.
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.
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.
Econoline Vehicles With (Production) Aspirator Drain Tube Built After March, 1984
Figure 22:
Drain Tube Replacement (Refer to Figure 22)
1. Pull the aspirator air hose from the aspirator outlet drain tube assembly.
2. Remove the aspirator outlet drain tube assembly from the barbed connection of the plastic evaporator drain tube projecting inboard from the bottom of the housing.
3. Remove the plastic evaporator drain tube and seal attached to the bottom of the evaporator housing by removing the two attaching screws with a 5/16 inch socket. Replace existing drain tube with E5UZ-19858-B drain assembly shown in Figure 22. Apply silicone sealer to the seal surface to insure a complete seal. Install seal, drain tube and attaching screws.
4. Plug aspirator air hose with rubber cap 382443-S or similar and tape hose out of the way on the underside of evaporator housing.
Econoline Vehicles With "Duck Bill" Drain Tube Built Prior to March, 1984
Figure 23:
"Duck Bill" Drain Tube Replacement
1. Remove the original drain tube located in the engine compartment on the bottom of the evaporator housing - two screws (Figure 23).
Figure 24:
2. Install the new check valve and drain tube assembly and retainer (service kit D6UZ-19858-B) using the two hex head 5/8 inch long, No. 10 screws provided (Figure 24). Note that the key tab fits into the slot towards the front of the vehicle. Two spring nuts are available in the kit, if required.
3. Apply a liberal bead of fillet of silicone sealer to both sides of the sealing surfaces to seal any air leak paths due to housing surface irregularities.
Procedure For Inspection And Repair Of Evaporator/Blower Housing Flange And Cover Leaks Into Passenger Compartment
Figure 25:
1. If equipped with an EEC IV system module in front of blower housing, remove module cover and dash flange attaching screws and lay module aside (Figure 25).
2. Check the lower flange of the blower housing to evaporator housing seal and the OUTSIDE-RECIRC door shaft lower pivot for leaks by plugging the drain tube and placing the FUNCTION lever in MAX A/C. Then, pour a sufficient quantity of warm water through the RECIRC door opening until the water level is approximately 3/8 inch deep. If leakage is noted, drain housing and proceed to the next step. Otherwise, remove plug from drain tube, drain housing and proceed to Step 6.
Figure 25:
Figure 26:
3. If leakage was noted from the bottom end of the OUTSIDE-RECIRC door shaft, blow compressed air around the end of the shaft area until thoroughly dry. Apply black silicone sealer, D6AZ-19562-A, liberally to cover completely the end of the shaft and boss to seal the area to the housing (Figure 26). If leakage was not noted from the evaporator core lower mounting screw, blow compressed air around the screw head until dry and apply black silicone sealer, D6AZ-19562-A, to cover the screw head (Figure 26).
4. If leakage was noted from the flange, remove the blower motor resistor connections and the blower scroll cover (Figure 25). Remove eight screws from the bottom and sides of the housing flange (two screws inside blower housing). Leave the top three screws in place, as well as the vacuum actuator shaft clip (Figure 26).
5. Pry the lower flanges of the blower and evaporator housing apart. Thoroughly blow dry the sealing areas with compressed air. Apply a continuous bead of black silicone rubber sealer on the sealing surfaces across the bottom flange and 1-1/2 inches up both sides (Figure 26). Carefully place flanges together and reassemble eight screws. Allow time for the sealer to set up and repeat leak test of Step 2.
6. Remove blower scroll cover and inspect blower housing cover seal for full contact impression with edge of blower housing. If full contact is not evident or seal is damaged, replace seal or repair skip areas with silicone sealer.
7. Reassemble blower scroll cover and electrical connections, and EEC IV system module (if so equipped).
8. Check for proper blower operation as described in the applicable Shop Manual.
Figure 27:
Service Procedure
NOTE: Prior to venturi tube installation, the evaporator housing sealing procedures and installation of the straight condensate drain tube as described in TSB 85-11-16 and TSB 86-9- 14, must be performed (Figure 27). (Do not install screen or drain tube in motor blower housing.)
Figure 28:
1. Remove the blower motor resistor connections from the blower scroll cover (Figure 28).
2. Remove the blower scroll cover (seven screws) and the blower motor (four screws) from the blower housing (push/pull the blower motor wire grommet toward the inside of the evaporator).
3. Set the A/C control to an A/C position.
Figure 29:
Figure 34:
4. Fabricate template A as shown in Figure 34. Align the template in the blower scroll housing by aligning the template small hole with the screw hole and scribe the D shape hole on the plastic blower housing. Remove the template and drill two small holes in the housing (Figure 29) in the scribed area. Then, cut away the remaining plastic with a sharp X-acto knife. Be careful not to damage the blend door frame during drilling and cutting.
Figure 30:
Figure 35:
5. Fabricate template B as shown in Figure 35 to properly locate the drain hole and insert it in the door frame assembly. Align the template notch with the lower rib as shown in Figure 30.
6. CAUTION: Insert a small section of scrap metal through the door opening and into the gap between the right side of the door frame assembly and the evaporator core face to prevent damage to the evaporator core during the following drilling operation.
Figure 30:
7. Drill a small pilot hole at the location indicated by template B and then follow with a 1/4 inch drill being careful to ensure that the edge of the hole is flush with the bottom floor of the frame assembly and also to not damage the evaporator core. Remove the scrap metal piece and template B after drilling. See Figure 30.
8. Clean the evaporator floor with a suitable solvent and dry thoroughly.
Figure 31:
Figure 32:
Figure 33:
9. Install the deflector (E7UZ-19B898-A) in the evaporator housing by applying RTV sealant to the deflector flange, inserting it through the door opening, aligning it with the evaporator face and the door assembly and then firmly pressing the flange against the evaporator case floor until the sealant sets. See Figures 31 and 33.
10. Apply sealant to the flange of the venturi tube (E7UZ-18K368-A) and insert the tube through the hole made in Step 4. See Figure 33. Ensure that the tube end is aligned with the hole made in Step 7. Verify that a 1/8 inch gap exists between the bottom of the tube end and the housing wall for trapped condensate to exit. See Figure 33. If required, slot the screw hole.
11. Inspect the blower scroll cover seal for full contact impression with the edge of the blower housing. If full contact is not evident or the seal is damaged, replace the seal or repair the skipped areas with RTV sealer.
12. Reassemble the blower, blower scroll, electrical connections and check for proper blower operation as described in the applicable Shop Manual. Be sure that the blower motor wire grommet is pulled into the hole in the housing.
PART NUMBER PART NAME CLASS
E5UZ-19858-B Check Valve Assembly A
Production Aspirator Drain
Tube Built March, 1984
thru September, 1984
D6UZ-19858-B Check Valve Assembly B
"Duck Bill" Drain Tube
Built Prior to March, 1984
E7UZ-19B898-A Deflector C
E7UZ-18K368-A Venturi C
382443-S Rubber Cap BS
D6AZ-19562-A Silicone Sealer A
OTHER APPLICABLE ARTICLES: 86-9-14, 85-11-16
WARRANTY STATUS: Reimbursable within the provisions of the Warranty and Policy Manual.
OPERATION: SP19858A85
TIME: 1.2 Hrs. - Vehicles produced from 1975-84 (produced prior to March, 1984).
1.5 Hrs. - Vehicles produced from March, 1984.
OPERATION: SP18424A86 - To be performed only after one of the above operations has been completed.
TIME: 0.9 Hr. DLR. CODING: Basic Part No. 19858 - Code: 48
(Figures 22 through 35 on following pages)