Vacuum operated step pushes man over the ledge

[Dean Rawson]

The restoration continues on the 81, 28' diesel, we scrapped the isuzu alternator, installed GM alternator to charge batts, installed interface module to operate tachometer, installed 12v vacuum pump with reservoir to operate step, the OEM solenoid was worn out , procured a napa # 2-2057 solenoid to replace it , I cannot get it to work , have tried switching hoses around, etc etc, abandon it and get an electric step or end this everexpanding project with a free matchbook

[NevadaGeo]

I find that bees can get into the strangest places and make little mud nests that will stop vacuum.

[dljosephson]

The vacuum step is a real puzzle, and the service manual doesn't have anything useful on it. Mine works, but takes a little longer than it should, probably because I have it plumbed wrong. I am still puzzling out two hose components: a length of hose that goes nowhere but is crimped/molded on the end to form a one-way valve, and a length of hose with a carefully cut hole in it. Once I have it figured out I will post a diagram.

Do you get vacuum at the hose from the pump? Can you make the step retract by connecting this to one hose or the other of the actuator?

[DaveFL]

Originally Posted by dljosephson

The vacuum ..., and a length of hose with a carefully cut hole in it.... ?

When mice or squirrels attacked the MH, they selectively chewed on wires and vacuum hoses.
Under the dash I ran my fingers along the hoses as I couldn't see them, came across an indent, worked my way under to visiually inspect and the critter had made a hole in 1/4 rubber tubing as if it had been drilled.

[ck21084]

Ok so I know nothing about your step but when I read the title I could only think that is was a news story about a step extending causing a man to fall over a cliff. LOL

[Dean Rawson]

Dean solved his step problem , since I no longer have the vacuum pump on the alternator, I am using an electric pump with a reservoir , too much vacuum and the electric solenoid can't shift, so I had a slick pneumatic valve that looks and works like a toggle switch, mounted it under the step warning lite on dash, 1 hose to switch from vacuum source, 1 hose to step vacuum diaphram, flip the switch up vacuum retracts step, switch down, cuts off vacuum and bleeds off vacuum allowing step to deploy, anyone need a new solenoid at half cost ?