Dash air/heat vacuum pump ???

[Dick Morse]

Anyone have any info on the pump Freightliner uses for controlling the dash air system ?

Mine won't shut off at higher altitudes but seems to work nearer sea level-- Is the cut-off swith integrated with the pump or separate ?

ReM

[Dick Morse]

Anyone have any info on the pump Freightliner uses for controlling the dash air system ?

Mine won't shut off at higher altitudes but seems to work nearer sea level-- Is the cut-off swith integrated with the pump or separate ?

ReM

[G Wayne]

I had problems with the vaccum control in our 04 Journey. Making all types of buzzing and vibrating. Looks like a fairly easy fix as its located on the drivers side out side "firewall"

Ford part number E3HT2A451BA went to Ford and they said the number is E3HZ2A451A but they have upgraded the part to a BRPV2 003953 02. It was not available for me here yet and so I have put of the repair until spring.

Wayne

[smlranger]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Dick Morse:
Anyone have any info on the pump Freightliner uses for controlling the dash air system ?

Mine won't shut off at higher altitudes but seems to work nearer sea level-- Is the cut-off swith integrated with the pump or separate ?

ReM </div></BLOCKQUOTE>

Well, that explains the problem I had with the pump on my '02 Journey while traveling the Beartooth highway in Montanna/Wyoming. The pump would not shut off. I had previously replaced a split hose which fixed the problem. I checked all my connections and could not find any new leak so I just figured the pump was going bad. I noticed the pump had shut off by the time we got out of those mountains. I did not consider high altitude as the factor at the time.

We did have another high altitude problem that was perplexing....one of the interior door panels on the fridge developed a significant bow and popped all the little storage shelves off whenever we opened the door. As soon as we got to lower altitudes, the panel resumed it's former position and I was able to reinstall the shelves. Interesting how the lower pressure affects things you would not expect.

[autofish]

The reason the pump runs at high alt. is because of the low air presure at alt. this is normal for this kind of vac pump . hope this helps

[Dick Morse]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by autofish:
The reason the pump runs at high alt. is because of the low air presure at alt. this is normal for this kind of vac pump . hope this helps </div></BLOCKQUOTE>


So it is really designed to run continuously as it would do if I moved back to the Colorado mountains ?

ReM

[Randy Chesnutt]

Alot of weird thing will happen when you get in the high altitudes. For me we start out at sea level and as we start going west are east we have a sleep number bed and we have to keep letting air out of so it want blow up. Our chip bags look like they will bop anytime.we have remember to releif preessure on alot of things, like lids on plastic bowels , meat that's rapped and the list goes on.So the higher you go the more weird things will happen and that pump will run.

[autofish]

may not be made to work that way but if they can build it cheep they will. mine does run all day above 10-12k feet alt. also have a hard time starting the cat above 11000ft but it is only rated to start 10000ft and below. Think they figure we only travel and stay below 10k ft.

[NO1RAINH20]

The pump is only supposed to run when there is a need for vacuum,it is installed by Winnebago not FCC,have any of you tried adding a vacuum resivior to help the alt. problems,has been used on passenger cars for years

[Dick Morse]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by NO1RAINH20:
The pump is only supposed to run when there is a need for vacuum,it is installed by Winnebago not FCC,have any of you tried adding a vacuum resivior to help the alt. problems,has been used on passenger cars for years </div></BLOCKQUOTE>

Perhaps it is a Winnebago installed system, I didn't research that-- Don't Freightliner OTR trucks use cab hvac systems ?

At any rate it appears that the vacuum pump is equipped with a reservoir by either FCCC or Winnebago as that is the first element in the system that the vacuum hose connects to--

I believe that the pump runs until a cut-off switch actuates at a specific vacuum and cycles to maintain that vacuum-- In my case , however, it runs continuously at higher altitudes-- I am not sure at what altitude the system fails to shut off, probably around 6000 ft asl--

Tnx,

ReM