Has anyone had issues regarding their vacuum system after using seafoam?

It seems like every system on my Blazer that requires vacuum, has some stupid issue. Shortly after I got the Blazer I used seafoam on the vacuum system. (The can says you can put it in your brake booster.)

My 4x4 did not work for quite some time. It recently started working again. I believe it was a vacuum issue, however i'm not sure. It kind of fixed itself? My heater controls, which i'm fairly certain are vacuum actuated have problem, you cannot switch from vent to defrost when you want. It just kind of happens on its own randomly. And I have a problem with the Evap system. (When I think is also a vacuum operated system..)

Could these issues have been caused by seafoam?
Anyone have a similar experience?

I'm not really one to jump to seafoam being the issue, but it's the only thing I could think of that would cause all these things to fail. -_-

 

Sounds like before you purchased the vehicle there was already a problem with the transfer case vacuum switch. The failure of this switch will allow ATF from the transfer case to be sucked up into the system causing the problems you have stated.

Seafoam through the brake booster line goes straight to the intake. There is no way it can get back into the the smaller lines that operate the 4X4 system and the HVAC controls.

The switch is inexpensive, even from the dealer.

 

No sir. The 4x4 worked great when I first got it. I can't remember if the heater controls did though. However, I noticed that (Sometimes) if I disconnect one of the vacuum lines in the engine bay, and reconnect it, my HVAC controls function properly.

Any idea why that might be?

 

ATF in the lines likely - you allow free air to flow thru the line when you disconnect it which likely allows the fluid to back down the lines and out of the way of the pull

or maybe there's something pinching a vac line that you're not seeing, try tracing them to make sure nothings pinched and inspect them for rot while your at it. they are after all rubber - which does have a tendency to break down and wear easily.

 

I wasn't even aware that ATF could get into my vacuum lines. I will definitely have to look into this more.

Thanks though.