Vacuum leak on 91 ZR1 - ZR-1 Net Registry Forums

kablamo · 12-31-2013

Hello all! I've been browsing this forum as I just got my first Corvette - a 91 ZR1 with 66k miles on it. I ran through the forum's inspection list and found a secondary port vacuum leak - runs and doesn't stop when key is in the ignition prior to starting.

Upon inspecting the secondary port vacuum I noticed that it was dangling (see photo) by the far right hand bolt (which was also loose). I also noticed that the main line coming off it it has disconnected just before the line that runs under the plenum. It looks like someone attempted to crimp it in the past and failed. Is it safe to re-fasten the secondary vacuum pump and replace the one connection and/or line to see if that fixes it?

Thanks for any tips and Happy New Year!

A26B · 12-31-2013

Picture did not post. If you are referring to a 1/8" black plastic hard line running from the pump to near the top alternator bracket..... there is a rubber hose that connects to a black plastic line that goes under the plenum. Sounds like yours may have disconnected or the line has broken. Both are common, re-connect the line.

We Gone · 12-31-2013

Welcome and congrats on the ZR-1. You can get a hand held vacuum pump to help find where it may be leaking, Also do a search many posts on vacuum issues.

http://www.zr1.net/forum/showthread....t=vacuum+leaks

kablamo · 12-31-2013

Whoops. Here are photos! Thanks for the tips! As soon as I'm back to the heated storage I'll try re connecting it.

gbrtng · 12-31-2013

kablamo - are you any kin to David Hobbs? Enquiring minds, you know. Welcome aboard - that's a good looking 91 - but pretty easy to lose in a snowbank ...

Cheers from a recovering Cheesehead.

Schrade · 12-31-2013

Welcome onto the boards there.

kablamo · 01-01-2014

Quote:

Originally Posted by gbrtng

kablamo - are you any kin to David Hobbs? Enquiring minds, you know. Welcome aboard - that's a good looking 91 - but pretty easy to lose in a snowbank ...

Cheers from a recovering Cheesehead.

I am not related to David Hobbs but us WI folks do stick together. Good luck on your recovery, our culture runs pretty deep !

Thank you all fort he warm welcome! I will try and re connect it once I'm back to heated storage.

12-31-2013	#1
kablamo Join Date: Dec 2013 Location: Wisconsin Posts: 15	Vacuum leak on 91 ZR1 Hello all! I've been browsing this forum as I just got my first Corvette - a 91 ZR1 with 66k miles on it. I ran through the forum's inspection list and found a secondary port vacuum leak - runs and doesn't stop when key is in the ignition prior to starting. Upon inspecting the secondary port vacuum I noticed that it was dangling (see photo) by the far right hand bolt (which was also loose). I also noticed that the main line coming off it it has disconnected just before the line that runs under the plenum. It looks like someone attempted to crimp it in the past and failed. Is it safe to re-fasten the secondary vacuum pump and replace the one connection and/or line to see if that fixes it? Thanks for any tips and Happy New Year!

12-31-2013	#2
A26B Join Date: Dec 2003 Location: Arcadia,OK Posts: 3,394	Re: Vacuum leak on 91 ZR1 Picture did not post. If you are referring to a 1/8" black plastic hard line running from the pump to near the top alternator bracket..... there is a rubber hose that connects to a black plastic line that goes under the plenum. Sounds like yours may have disconnected or the line has broken. Both are common, re-connect the line. __________________ Jerry Downey JERRYS LT5 GASKETS & PARTS http://www.jerrysgaskets.com 1994 *ZR-1*, Black/Black, Lingenfelter Aerobody, 416cu in, 3.91 gears, coil-over susp, Brembo brakes, etc. 2016 Black-Red, 3LT-Z51 Auto 8-speed.

12-31-2013	#3
We Gone Join Date: Apr 2004 Location: ATL. GA. Posts: 2,170	Re: Vacuum leak on 91 ZR1 Welcome and congrats on the ZR-1. You can get a hand held vacuum pump to help find where it may be leaking, Also do a search many posts on vacuum issues. http://www.zr1.net/forum/showthread....t=vacuum+leaks __________________ Steve 1990 Steel Blue/Black #2355 1990 Red/Red #1473 1991 Quasar /Black #118 Sold 1991 Turquoise/Black #766 Parted Out 1993 Yellow/White #179 Sold 1990 Black/Gray #1361 Headers/4:10s Sold Last edited by We Gone; 12-31-2013 at 01:23 PM.

12-31-2013	#5
gbrtng Join Date: Feb 2006 Location: San Antonio area Posts: 1,179	Re: Vacuum leak on 91 ZR1 kablamo - are you any kin to David Hobbs? Enquiring minds, you know. Welcome aboard - that's a good looking 91 - but pretty easy to lose in a snowbank ... Cheers from a recovering Cheesehead. __________________ “Buy the best example of what you want, and pay whatever it takes. That way, you cry only once.” ~ Bruce Meyer Last edited by gbrtng; 12-31-2013 at 05:50 PM.

12-31-2013	#6
Schrade Join Date: Dec 2012 Location: NC Posts: 1,786	Re: Vacuum leak on 91 ZR1 Welcome onto the boards there. __________________ I'm getting my snappics / threads removed blindly as fast as I can, to get in compliance with copyright / license TOS on the boards here (lots of FSM pages and other copyright / license violations on my part; sorry guys). And thanks to all the guys who didn't whine when I posted those FSM copyrighted / licensed stuff in my threads... ( :thumbsup: [b]and to think I complied with a mod's request to delete a pic of him in a Challenge Car in NCM Museum, so he wouldn't get in hot water)[/b] Thanks to several guys here for sending parts FREE; BearlyFlying, WeGone, Geezer, GoldCylon, and more there, TonyD, mike100, fletchusmc... 1990 #2794; 4L60e Stage V by RPM Transmission, TCI Dedicated TCM, OBX Stainless, Power Effects 3" [IMG]https://lh5.googleusercontent.com/-GHpfzty7DVU/UQn-0Ru2xAI/AAAAAAAAA14/08mz1p4QLD4/s445/Screenshot-5.png[/IMG]