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Vcuum canister under passinger fender


kens96

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Was looking under the car after the tranny repair and noticed a small vacuum canister under the front passenger fender. The 1/8" line to it is broken and when I follow the path it looks like it goes into a "T" connector with one part going into the firewall where a wire harness goes. (looks climate control related) and the other goes on the engine somewhere. I have no codes and everything works. Looks like the line is plugged with trash.

Can anyone tell me what is the purpose of the canister and what is its function?

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Ken that vacuum canister that looks like a black bomb, holds vacuum originating from manifold vacuum for the HVAC and vacuum brake release systems. When I was having problems with the air flow from my AC vents stopping when the engine was labored up a hill, I replaced all hoses, check valves, T's, black nylon tubing and the connection at that tank. I have a diagram of the system and I will post it. By the way, that did not fix my AC air loss problem it was under the dash, I think the part is called the programmer, the vacuum hose block needed to be reset

I spied you looking at HVAC air flow delivery before, if that tubing is cut from the removal of the tranny, that is the problem. I was able to order a new tubing (it has lots of bends in it) from the dealer, I cant recall how much. I might have the old one but I am not sure if you have a problem getting one, Ill check. A local scrap yard would be a good place to get one also. It is easy to damage that tubing R&Ring the carriage

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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Ken, I heavily edited my post above, please re-read it. I scanned your initial post but didnt read it, I edited my response to your post more accurately now.

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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I want to stomp on my laptop it is SO SLOW... add to that my slow wireless connection...

I finally found this

96_Engine_Vacuum_System_2.jpg

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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That is the system I am talking about. It is cut right at the bend in the pipe before the connection to the canister. I'm going to cut it back to where it is not clogged and splice it . Bought some tubing and connectors at Advance Auto. Looks like its been that way for some time. Funny thing is I have no issues with the HVAC or the brake release. Everything work fine.

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Used some Dorman 5/32 Vacuum tubing and 2 5/32 rubber splices. Blew the line out backwards from the T. Line is clear. Pulled a vacuum on the line to the canister with the Mighty Vac and it pulls and holds. Spliced it together and all appears to be working. Will get her on the road Tuesday after the alignment and see how it runs.

Busy tomorrow with the 98 Corvette. Oil sending unit crapped out reading 130PSI. Chevy in its wisdom placed this sending unit under the intake manifold! Has to come off to get to it. Happy President's Day.

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Used some Dorman 5/32 Vacuum tubing and 2 5/32 rubber splices. Blew the line out backwards from the T. Line is clear. Pulled a vacuum on the line to the canister with the Mighty Vac and it pulls and holds. Spliced it together and all appears to be working. Will get her on the road Tuesday after the alignment and see how it runs.

Busy tomorrow with the 98 Corvette. Oil sending unit crapped out reading 130PSI. Chevy in its wisdom placed this sending unit under the intake manifold! Has to come off to get to it. Happy President's Day.

Ken,

Your statement about the placement of the oil sending unit brought back an old memory. I know that this is :offtopic:

When Chevrolet designed the Corvair engine, they put the oil pressure idiot light switch in the engine cooling air plenum next to the exhaust manifold. The original switch had a metal base & looked somewhat like an over sized golf tee with a black plastic cap. There was a single tab to hook the sender wire to. This was the same part that they had used on V-8s and in-line sixes for several years.

The problem was, being in close proximity to the heat generated by the exhaust and the engine it's self, the black plastic would crack and spray engine oil onto the exhaust manifold!

In addition, most Corvairs used the engine heated air to supply heat to the car.

One winter, I was driving our 1962 Corvair when that sending unit let go. The car's interior instantly filled with white oil smoke! Why it didn't catch fire, I'll never know.

Let me say this, I did have enough piece of mind to set the emergency brake and turn off the ignition as I bailed out! I remember a long walk to someone's house so I could call home. My dad thought that I had been thrashing the car until he found out what actually had happened.

We had it towed to a nearby Chevy dealer. They said that there had been a recall and installed a heat resistant sending unit. It looked similar to the old one, except the black plastic had been replaced by what looked like porcelain.

I have always wondered how many Corvairs burnt up because of that poorly thought out switch.

I guess that this could be filed under either ancient history or useless information! :P

Britt

Britt
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I had a 1986 Corvette with the LT1 that did the same thing! Just as I was pulling into the garage the oil sending unit blew and we had better than a quart of oil in the engine bay and on the floor . Grabbed the fire extinguisher looking for flame up. What a mess !

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Off topic but I had to share.

Replaced the oil pressure sending unit on the Vette. Took 4 hours to remove and replace the intake manifold and all the "stuff associated with it. Used a digital torgue wrench to make certain I didn't over tighten anything. Start the car and everything is perfect. Clean up . Go out to get gas and after 10 minutes the gauge drops to zero and I get a Low Oil Pressure on the DTC along with Check Tire Monitoring System and Service Vehicle Soon. Check codes and all are history. Get home start the car a few times still getting zero oil pressure. Come home tonight and start the car after it sat a day and get 53 PSI on my oil pressure gauge and the DTC items mentionded above. Let it arm up and the gauge drops to zero. Darn thing looks like it has a heat related short in it. I'm going back in next week to replace the sending unit after I get an oil pressure sender relocation kit to move it from under the manifold. Another 4 hours, What a pain.

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