ourkid2000

Good day all,

I'm pretty new to the whole vacuum driven headlights system and I'm trying to learn as much as I can. My 66' headlights seem to be working fine after I replaced a leaking T fitting (the one next to the check valve near the brake booster) but it occurred to me that there must be some calibrated leaks in this system? I mean, you can't endlessly pull vacuum as you would probably damage something eventually right?

So how long after you shut the car down do you have before you can't put the headlights up anymore? I'm assuming the check valve allows you to retain some vacuum in the reservoir so that the headlights can come up without the car running?

Are all the T fittings special or is it just a select few? I'm thinking that the T fittings would be where the "calibrated" leaks are placed? I just shoved any old T fitting into the junction by the brake booster because the old one was leaking like crazy. Am I way off in my thinking here?

cfair

It would be a good idea to cite year / model. But this time it’s easy since (I think) only Toro’s had vacuum influenced headlights.

I think it’s a reasonable expectation that vacuum will leak down 10-15 minutes after engine shutdown. If you get more, great!, but if not, I’d still consider the parts fit for purpose.

I’ve been troubleshooting my ‘66’s vacuum systems over past few months. Just a couple of pointers below. I have 1 car that will hold vacuum over night no problem and another that leaks down in 5-10 minutes after engine shutdown. So it goes.

Tool & supply parts wise, get a vacuum hand pump and 6 or 8 feet of 5/32”, 7/32” and maybe 1/4” vacuum hose.

1) You’re well advised to both have and test your accessory vacuum tanks for fitness. 50 years later they can have rust or seal-related problems which keep them from holding vacuum after engine shutdown. If you’re really into it, you may want to add an auxiliary vacuum reservoir on if you can hide it in fender or place it on the firewall conveniently.

2) It’s a good idea to have a check valve on the inbound line to any diaphragm that can leak. If you have a problem, at least then it won’t spread to other still-good components.

3) Back in those days, GM used brass and/or steel T fittings. No one does that anymore, you can only buy plastic new ones (as far as I know). If you have metal and they test good, keep ‘em, otherwise plastic T fittings and Y fittings and junctions will work fine.

4) Test your vacuum powered accessories themselves - in your case the headlight raising apparatus. If those diaphragms are torn, shot, leaky or whatever, no amount of trouble shooting will magically restore them. I have no idea if Toro headlight actuators can be restored, but a good coating of high vacuum grease may extend their life or restore function somewhat.

5) Pay close attention to vacuum line sizes both at the vacuum source and whatever they’re providing vacuum to. Sometimes GM would reduce the line size (as in power door locks) in the middle of the line and unless you’re looking for it, you might not notice.

6) If you have a vacuum trunk release and/or vacuum power door locks, use check valves to isolate these systems so as not to negatively influence your headlights. Same for your heater /ac controls.

7) Usually the vacuum accessory stuff was vacuum working against a spring, with some kind of pivot point, hinge or gizmo. It’ll never hurt to pull the units, clean and grease moving parts so that if the vacuum stuff is working correctly, you make it’s job easier.

Here are some additional vacuum accessory tips which may help you:
https://classicoldsmobile.com/forums...s-leak-164239/

Hope you get it working to your satisfaction!

Chris

ourkid2000

Good info, sorry I should have clarified. Although this is the Toronado forum and I did mention it's a 66 I should have said I have a 66 Toro with the vacuum headlights