I posted a month or two ago about the HVAC in my 06 E250 loosing airflow when under heavy load. I've replaced the 1-way check valve, confirmed the vacuum reservoir isn't leaking, and also that there's no leaks at the vacuum servo which operates the HVAC door.
However, when I try to pull vacuum from the loose end of the hose from the servo going back upstream it doesn't hold vacuum at all. The hose is nice & pliable & I don't hear any leaks, but it's only about a foot long & attaches to this...thing. It's up under the dash far enough that I can't really reach it, but the vacuum line for the HVAC servo runs into a connection on the top & out another on the bottom. There's also another vacuum line running in/out of its own ports top & bottom. Then there's another set of unused ports.
What is this thing & is it a likely source of my vacuum leak?
Not sure what that part is, but every E series vacuum leak I've ever had has been under the hood near the blower motor. There is a line that supplies vacuum to the system there. It cracks due to heat.
In an emergency, you can pop the panel out of the center of the dash and zip tie the vacuum motor into position. It springs to defrost and uses vacuum for all other positions.
They're part of the vacuum harness. Can't tell which ones from your pic... hopefully mine is readable!
This vacuum line is where I've always found the problem.
In reply to Toyman01 (Moderately Supportive Dude) :
The vacuum servo on mine is in the passenger footwell, not too far up. I'd originally used some bailing wire to keep it in position, but was concerned I might need to use the defrost setting at some point.
I can see the vacuum canister & where the line runs to it under the hood/cowl, but can't see where it terminates behind all the other stuff. I'll try to pull that stuff out of the way. I'm thinking if I can find the hose leading out of the reservoir I can just run a new one to the servo inside.
In reply to Saron81 :
I can't really read the tags, but I'm guessing the part in my pic is either the one highlighted in green, or the one directly below it.
In reply to Toyman01 (Moderately Supportive Dude) :
I just watched your vid. At about 1:20 when he removes the cover on the dash, the part between the two actuators is the same part in my pic above - but mine is in the passenger footwell.
I'm going to check again, but I don't think my hose comes in through the bottom of the footwell like his. Regardless, the idea of getting another reservoir to plumb in & running the hose through the fender definitely seems possible.
Edit: I just checked, mine is just like the one in the vid. Time to find a small canister I can stick up in the footwell to use as a vacuum reservoir.
In reply to Pete Gossett (Forum Supporter) :
Edit: Never mind. My last van was a 02. There must have been some changes between then and 06.
Chevrolet Express vans used a round vacuum reservoir that may fit under the dash of your van, has 1 port. I used one to repair a 2009 E350 that had a cracked reservoir. Ran a T fitting and ziptied under the dash on the passenger side above the fuel pump reset switch. Rockauto shows a dorman pn 47083 for less than $10.
In reply to mjrj (Forum Supporter) :
Sweet, thanks!
Thanks to Toyman's vid & mjrj's p/n I think I have it fixed.
I had to install the vacuum reservoir on top of the fuse box in the engine bay & run a vacuum line to the other side where the factory T is located. Then, following the guidance of the vid, I used a coat hanger to snake a new vacuum line through the fender & into the passenger footwell. There I pulled the OE line out of the firewall & attached the new one to it.
I ran the van for a few minutes & made sure the vacuum servo retracted, then turned off the engine. The van remained retracted for at least a minute, so the system once again holds vacuum.
