Dear Olopezm
I fixed the issue of vent deflection to the defrost position. I made two amendments:
1.) fixed check valve vertically see diagram No. 1.
2.) repositioned the whole check valve and vacuum reservoir assembly inside, under the dashboard
I fixed the valve vertically because the air can travel from the white side to the black side only. In the cylindrical part which is between the two white and one black tubes (marked red), diagram 2 &3there is small thin circular plastic disk like membrane. This plastic membrane closes the way back to white tubes. If the valve is vertical, the sheet will be horizontal, thus closing the white tubes by its weight, all the time.
One of the white tubes is connected to the vacuum canister. From the other white tubr, a black hose goes to the control knob, from which different hoses go to the different actuators. See the connection diagram (NO. 4) of the hoses. Leak can occur at any of the connection points between manifold and the red hose, hoses and check valve, vacuum canister, control knob, and actuators; and the hoses, check valve, vacuum canister and actuators themselves. However, the most probable site of leak is on the engine side, where the changes in the temperature due to engine heat and cold external temperature can damage the plastic parts by making them inflexible.
I removed the hose, the canister and check valve, which I had replaced recently, plugged the open ends, dipped all of them in a bucket of water and applied pressure to one end. I came to know that all the joints and vacuum canister were leaky, even though I had secured all the joints with silicon and wires. There was a small phalange of residual plastic material along the whole length of the tubes of the valve. This phalange was preventing airtight fitting of hoses with the check valve. I repaired the leak of the vacuum canister and filed it to smoothen the tubes of the check valve. I took a long new hose to connect it to the manifold on the one end and firmly connected the other end to the black hose, which is connecting the vacuum canister to the control knob, to pull the new hose inside. I could find much place behind on the glove box just on the passenger side of the central console and fixed the check valve and vacuum canister on the new place; so that any future service is easy. Other advantage was that it gave much space to replace the metallic heater hose. Alternatively, creating 15-inch vacuum in all hoses, check valve, canister control knob and actuators, and a fall in vacuum by 1 inch per min will detect leaky part.
see Link:
http://www.automotiveforums.com/vbul...02#post6921202
http://www.automotiveforums.com/vbul....php?t=1074091
http://www.automotiveforums.com/vbul....php?t=1052185
AzharJ