Buick LeSabre Heating / Cooling

huntswnm

Hey thank you very much! I had heard about the vacuum canister but had all but given up finding that thing. So I tracked the vacuum hose from where it goes into the intake. There was a couple areas where the hose was dry rot so I replaced that. Check valve seems to be working fine. The line seems to get reduced in diameter after the check valve. Once under the car I found the canister and the line was disconnected from it. However, the hose and elbow fitting were so rotten they crumbled in my hand. The line at this point is very small in diameter and must get reduced somewhere in the bundle between the T connector and the canister. I started the motor and the system has good vacuum at the T connector. However once underneath there is no suction on the line at the canister.
I suppose my question is do I have to follow the line back all the way through the bundle from the canister to the T connector, or can I simply run a new line from the T connector down to the canister and bypass all the current hose?? Once I get suction at the end of the hose at the canister I can then hook it up to the canister and check it for cracks. Think I am on the right track!?

Edit: If I indeed can bypass the tubing by just running a new line from the T to the canister, can I get away with running the slightly larger diameter hose all the way down, or does it need to be reduced somewhere in the middle like the original seems to be?

Jeff

imidazol97

As long as the ends fit on the T and the cannister end, run any vacuum line you want.  Use electrical tape or ties to hold line line in place against air buffeting. I'm glad you found the problem area. 

huntswnm

Ok will do! As I sat and pondered this yesterday evening I got to thinking that could there be a possibility that the leak is on the other side of the T? If it is on the side that is running into the cab then that could account for the lack of vacuum on the canister side. Maybe I will try to plug the line going into the firewall and see if I get vacuum at the canister first.

imidazol97

Is the reduced line in the length from the T to the canister smaller than the nylon black line from the
intake manifold? I could see why they might use a reduced to slow increases and drops in pressure
from the canister. But I'd just put a rubber line from the roll they cut for you at O'Reilly/Checkers,
for example.

As to loss of vacuum inside the cabin, I'd fix the outside. If you had crumbling rubber that probably
was where your leak was. I know the rubber on the load-leveling rear struts on my 98 leSabre was
powered and broke when I touched it. After that, see how the inside works when car is accelerated
for a short time up a hill after running normal low throttle opening and high vacuum.

After that is fixed, you should be able to have the inside on heat, turn off the engine and be able, with the key ON to push buttons change to defrost, windshield/heat, and hear the vacuum diaphragms (motors they call them) move the parts as the vacuum is used up over maybe 10-15 seconds.

If the inside unit changes and directs the air flow where it's supposed to go for each setting, I'd
recommend being happy. I would not start digging into the inside parts unless absolutely
necessary. (Been there, done that with my automatic system on 98).

Again, good luck, and if you have any questions I know enough to answer, I'll be happy to help.
I do have a 98 factory service manual if you need pictures. The 98 made 200K miles and I
traded it. I had skipped servicing and replacing things that needed work but it ran great and
transmission was great.