68' vacuum system problems/questions?
Thread Starter
Drifting
Joined: Oct 2008
Posts: 1,369
Likes: 12
From: wichita kansas
68' vacuum system problems/questions?
restoring a 68' BB coupe, just finished all the wiring, and engine is broke in and running good. i ran ALL new vacuum lines, relays, actuators, check valve, etc, everything is new, and TRIPLE checked on routing and correct hook up. the only thing that is old is the original vac storage tank, which i now suspect leaks. with engine running, i cannot build up any vacuum reserve in system to activate anything. the tank looked solid, i didn't test it, just bead blasted in and painted it. (oh, i did run a bead of JB Weld around the complete seam just in case of a pin hole or something)
question is this, i have read/heard that some people just by-pass the vac storage tank, and everything still works fine, (obviously you wouldn't have any reserve to open headlights or wiper door without engine running) but are there any other pros or cons that i'm missing? how would i go about by-passing it, or is there some way i can test the storage tank now that it is in place? (which is a bear to get in and out btw...LOL)
thanks, and let me know if you have experience with this....Rick
question is this, i have read/heard that some people just by-pass the vac storage tank, and everything still works fine, (obviously you wouldn't have any reserve to open headlights or wiper door without engine running) but are there any other pros or cons that i'm missing? how would i go about by-passing it, or is there some way i can test the storage tank now that it is in place? (which is a bear to get in and out btw...LOL)
thanks, and let me know if you have experience with this....Rick
Burning Brakes
Joined: Feb 2001
Posts: 929
Likes: 5
From: Marietta GA
Yes, I had trouble with my '68 vacuum system and couldn't figure it out myself. It ended being a bad wiper door actuator. Anyway, the shop, to isolate the problem removed the hoses from the vacuum tank under the left fender and merely connected the hoses together using a vacuum hose connector. When I picked up the car everything worked perfectly. A few months later I was poking around the engine compartment and realized they had forgotten to reconnect the hoses to the vacuum tank.
If you bypass the tank, it is as you describe, everything will work fine, except no vacuum reserve when the engine isn't running. You just have to remember to turn off headlights and wipers before shutting off the engine. No big deal.
By the way, I removed my vacuum tank and had it checked at a radiator shop. It had several leaks, which were fixed. Keep in mind that if you have a leak in the vacuum system for the wipers or headlights, it is NOT isolated from the rest of the engine, and can cause your engine to not run properly. The same as any other engine vacuum leak.
If you bypass the tank, it is as you describe, everything will work fine, except no vacuum reserve when the engine isn't running. You just have to remember to turn off headlights and wipers before shutting off the engine. No big deal.
By the way, I removed my vacuum tank and had it checked at a radiator shop. It had several leaks, which were fixed. Keep in mind that if you have a leak in the vacuum system for the wipers or headlights, it is NOT isolated from the rest of the engine, and can cause your engine to not run properly. The same as any other engine vacuum leak.
Thread Starter
Drifting
Joined: Oct 2008
Posts: 1,369
Likes: 12
From: wichita kansas
thanks guys! Ernie, i have no problem whatsoever "digging in" and locating a problem! God knows i have done this with many other areas of the car, most recently evidenced with my wiper motor woes! LOL....i guess the point to my post is this: IF the problem is a storage tank that leaks (which i'm pretty sure is the case) then is there really any reason i couldn't leave the pretty restored tank right where it is for cosmetic reasons and just by-pass the vac lines that go through it to develop the reserve vacuum? these original 68' (and i believe 69" tanks) that are in decent working condition are not easy to come by. thoughts? Rick
Thread Starter
Drifting
Joined: Oct 2008
Posts: 1,369
Likes: 12
From: wichita kansas
ok, more info, and more questions....i by-passed the storage tank for testing purposes...still nothing! i can't get the wiper door to react at all with engine running. i do not have headlight vac lines hooked up yet, but both lines running forward to headlights are blocked off (so shouldn't affect anything right?)
the only other thing i did not replace brand new other than the storage tank is the solenoid valve that mounts to back of tach. if that solenoid was bad, would it possibly affect the entire wiper door actuation? i can't imagine what else it could be, all new hoses in proper place, new wiper cannister, new relay, new check valve and filter, new over-ride switches/valves, etc....thoughts? Rick
the only other thing i did not replace brand new other than the storage tank is the solenoid valve that mounts to back of tach. if that solenoid was bad, would it possibly affect the entire wiper door actuation? i can't imagine what else it could be, all new hoses in proper place, new wiper cannister, new relay, new check valve and filter, new over-ride switches/valves, etc....thoughts? Rick
Team Owner
Joined: Sep 2006
Posts: 31,278
Likes: 4,372
From: Westminster Maryland
Hi Raz,
From what I read here I'd trust NO new headlight and wiper door parts!!!
I think you need to have a Mity-vac with a gauge, and a troubleshooting guide like the one from Willcox or Dr. Rebuild that tells you how to test the function of EACH component INDIVIDUALLY.
Please... I'm not being an *** here...you've GOT to check the PARTS!
Regards,
Alan
From what I read here I'd trust NO new headlight and wiper door parts!!!
I think you need to have a Mity-vac with a gauge, and a troubleshooting guide like the one from Willcox or Dr. Rebuild that tells you how to test the function of EACH component INDIVIDUALLY.
Please... I'm not being an *** here...you've GOT to check the PARTS!
Regards,
Alan
Thread Starter
Drifting
Joined: Oct 2008
Posts: 1,369
Likes: 12
From: wichita kansas
Hi Raz,
From what I read here I'd trust NO new headlight and wiper door parts!!!
I think you need to have a Mity-vac with a gauge, and a troubleshooting guide like the one from Willcox or Dr. Rebuild that tells you how to test the function of EACH component INDIVIDUALLY.
Please... I'm not being an *** here...you've GOT to check the PARTS!
Regards,
Alan
From what I read here I'd trust NO new headlight and wiper door parts!!!
I think you need to have a Mity-vac with a gauge, and a troubleshooting guide like the one from Willcox or Dr. Rebuild that tells you how to test the function of EACH component INDIVIDUALLY.
Please... I'm not being an *** here...you've GOT to check the PARTS!
Regards,
Alan
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Thread Starter
Drifting
Joined: Oct 2008
Posts: 1,369
Likes: 12
From: wichita kansas
no Mike.....with engine running, and everything hooked up, i get nothing from the wiper door when i turn on the wiper motor or try to use the over-ride. the door is stuck in the open position right now, so wiper motor does work, (since limit switch is closed), but i can't get the door to even try to close. the 2 headlight vac lines are not hooked up yet, but are blocked off, i do have vacuum up front on the big line when i check it, and of course have vac at the manifold fitting when i check there. btw, the wiper door worked freely before i hooked it up to the canister, so i don't believe the linkage/transmission for the wiper door is in some kind of bind. i do not know whether the solenoid switch mounted behind tach works properly, and don't know if that would affect anything other than the over-ride circuit. i guess it's possible, like Alan said, that i have a bad canister or relay even though they are brand new! it's just frustrating when you take your time, replace almost all of the parts/components with brand new, and meticulously run new hoses properly, that it DOESNT work! and like i said, it doesn't act any different when i by-pass the vacuum storage tank (which could be good if it turns out that the tank is fine, and the problem is elsewhere, IF i can FIND the problem) Ideas??? Rick
Le Mans Master
Joined: Jun 2005
Posts: 5,447
Likes: 3
From: Syracuse NY
I've got to pick one up myself these are a good thing to have.
http://www.tooltopia.com/mityvac-mv8...n=shopzilla_r1
Repo parts suck and should be tested before installation IMHO
http://www.tooltopia.com/mityvac-mv8...n=shopzilla_r1
Repo parts suck and should be tested before installation IMHO