Auxiliary vacuum pump


Chaz60

New Member
We have a '94 Aerbus on a Ford chassis. When using the automotive AC and pulling long grades the vacuum pressure is inadequate to hold the heating/AC bafflle doors in the cooling position. Not a problem in winter, but when it's hot that's a different story. I want to install an auxiliry vacuum pump to assist the manifold vacuum. My problem is I haven't been able to locate a supplier. Does anyone have a suggestion where I might find one :question: :question:
 

Gary B

Senior Member
Auxiliary vacuum pump

Hi Chaz60, how about just installing an aux vacuum acumulator you know a vacuum tank. Just an idea good luck. I know from experience on my F-350 that the vaccum hoses got switch by accident to a smaller accumulator and the A/C did the same, I traced the lines and got them back on the large tank an all was fine again. :) :cool: :bleh: :approve:
 

StaffNav

New Member
Auxiliary vacuum pump


I have exactly the sme problem with my Nissan. There is an auxiliary Vacuum pump but it has been failing and is now shot! I get blasts of hot air regularly and the cruise control cuts in and out. I am looking for any substitute independent adaptable pump and hoped that you might have found an answer. If I do I will get back to you!! Regards! Bill
 

C Nash

Senior Member
Auxiliary vacuum pump

Hi Bill,
Ford still has not fixed this problem :( . I have a 2002 HR and it does the same thing. Planning on a larger vacuum tank like Gary B was suggesting with a check valve installed. Haven't even looked to see what size is there now or checked to see if hose may be kinked. Only time I think of it is when it happens on the road. Guess I could go ck right now :laugh:
 

StaffNav

New Member
Auxiliary vacuum pump

I've since been told that an 'old' Volvo or a 'GM' powered vacuum with the three (3) leads will act as a replacement for my faulty auxiliary Vac. pump/canister. ( the aux. pump cuts in only when the vac. level falls) One line is ground, one power and one a contol line that must be used to keep the vac. pump from working full time. The 'control line'makes sure it works only as required - when the contoller passes the 'signal ( turns 'on'. I'm going to see sbout having the original rebuilt by a German armature tech. If that fails I'll be checking GM & Volvo.
 

Flyboy

New Member
Auxiliary vacuum pump

We had a similar problem with our previous motorhome. The one 5" round accumulator tank just wasn't enough. Did some searching in the junk yard and ended up building my own tank from some left over PVC pipe. I had a 2' section of 3" PVC pipe. Took two end caps and drilled a hole in the center of one cap. Screwed in a threaded hose barb (3/8" pipe thread on one end and a 3/16" hose barb on the other) several times until it cut it's own threads. Then used a sealant on the threads to prevent leaks. Glued the two caps to the pipe and mounted it with plastic wire ties. Then T'ed into the vacuum line going to the existing tank. Worked great... cheap fix. :)
 
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