Welcome to the Corvette Forums at the Corvette Action Center!

vacuum reservoir tank removal


72 Bluz

I need to inspect the reservoir tank on my 72 for leaks, think that's where my leak is. My problem is removing it. It appears the easiest way to do this is to take it out through the fender louver grill, if it will fit. Has anyone done this? Any suggestions for this are appreciated.

I think it would be easier to remove thru the top, with the hood removed.
That's what I thought too, Ken. Because of it's size, it appears that the master cylinder and fluid tank would have to be removed for clearance. The headers seem to obstruct it from the bottom.

Huh? VAC tank..or coolant tank??

Is it different than a 73? VAC tank is welded into the frame ( I think )

My coolant tank comes out from the top with ease...well with a bit of wrestling... but take the HOOD OFF? I don't get it. We are talking about the white nylon bottle
mounter to the inner fender? right?

How about pressurising(sp) it before removal to check for leakdown....

I thought he was talking about the vacuum tank which is in the front of the car behind the headlights and would require removing the hood.

Now, since he's mentioned the master cylinder I think he's talking about the "windshield washer" bottle. Mine had to come out of the bottom. I suppose you could take the master cylinder out and come up thru the top.

Did the coolent recovery tank switch over to the passenger side by '75? Mine is on the passenger side and really easy to get out.
not the windshield washer bottle

This tank is adjacent to the washer bottle and mounted on the fender well under the hood. It has 3 vacuum lines going into it. It is somewhat rectangular, metal and about the size of 3 cigar boxes on top of each other. Last night, I hooked the vacuum pump to it. After 10 -15 pumps, I could not get a reading/vacuum. I'm assuming this is the vacuum reservoir tank because of the 3 lines/hoses going into it (I read this off a vacuum troubleshooting thread from somewhere). Anyway, my understanding of the tank is that it should hold a vacuum. Because of it's position in the engine compartment, it's impossible to fully inspect it for leaks without removing it.

The holy book

GM shop manual for a 73

Show's the following
That the TANK is part of the entire front end assy
which unbolts and the end of the two foward frame rails. It's part of the whole front end assy and looks like a BEAR to pull out.

I hope the earlier ones are easier.

I would cap all the lines and do a pressure test first ( you know soapy water and all that) THEN decide to yank it out..

Ah...now that I read the last post

I would remove the out going lines... (put on rubber caps or loop a piece of hose ) and re-test to isolate the tank itself.... the rubber lines are the most prone to fail. Try the pressure thing.. you can hear a leak easier, but a mighty vac pump works good too!

Hey, Mike

am I looking at the right thing? I know the tank in other models was up front with the headlight assembly. Xena's a 72, can't imagine what else this could be.

I would think......

That a 72 & 73 are close and the VAC system wouldn't be all that different. Let me dig a little more.. do you have the big tube running under the headlight from frame rail to frame rail ( about 5" in Diameter?)

Can't answer

that until I get home and look. Thanks for your help.

Does the car have AC?

and is it all there?


I do not know why a tank would be down there, what side is it Drivers or Pass?


I don't think there was an evap cansiter that early, and the car dosen't have cruise ( unless somebody bodged it in ) I seem to remember something down there however...still stumped


The 73 does have an evap canister!!!!!

It's located drivers side... between the firewall & backside of front left fender..mounted LOW like an inch above the bottom plate there are 3 screws which hold it on which go thru the inside of the
( front wheel well) back.

There are 2 fuel lines going to it that I can identify and maybe 1 vac line... It's weird, it's round however but yours might be different.. and maybe a late build 72....

It looks like there is a Vapor line running from the back (Drivers side of the tank ) foward to the canister, mounted on the inside of the frame rail

A drain on the bottom of the canister which doesn't show me where it goes, Back to the seperator maybe and a VAC line on the top of the canister.

Are there 2 lines on your fuel pump???

Hmmmmmm food for thought,

You're stumped?

I'm thoroughly confused (and showing my mechanical ignorance). If I understand you correctly, Mike, what I think is the VAC tank has something to do with the fuel system? Then the VAC reservoir tank would be up around the headlight assembly?:confused

I believe the car is a late 72 build. The 3 ports on the tank all face the firewall - 1 at the top and 2 in the bottom half of the tank.

Vac Rez

My 71 has the large black steel vacuum rez rank (bears some resemblance to a refrigerator compressor) near the MC & washer bag, at drivers side. Don't have the car nearby so I can't look to see how to remove ... I've never tried to. I'd take prior advice & plug all lines and do a vac test w/ a mighty vac. I'd be real cautious/hesitant doing a pressure test.
I have my 72 almost completely torn down, so its pretty easy to see. There is a vacuum reservoir behind the driver's side wheel well, its just a square steel tank. Underneath that is what I believe is a fuel vapor cannister, there are 3 lines attached and one goes aft, presumably to the fuel tank.

Looks like they both can be removed through the egg crate opening, and there is a filler panel underneath that can be removed for access from the bottom. I'm taking them both out along with the brake booster this weekend.

I just took a digital picture of it but I can't get to my website yet to upload. Send me an e-mail address and I'll mail it to you if it will help...rkeithjohnson@mindspring.com

Corvette Forums

Not a member of the Corvette Action Center?  Join now!  It's free!

Help support the Corvette Action Center!

Supporting Vendors


MacMulkin Chevrolet - The Second Largest Corvette Dealer in the Country!

Advertise with the Corvette Action Center!

Double Your Chances!

Our Partners

Top Bottom