All,
On my Regency I've had nearly a year I just discovered my Vacuum gauge is reading 0, or the needle is pegged to the left indicating it's reading no vacuum.
My problem is I'm not sure on my coach what the vacuum pump functions to do. I can only guess it's for the doors on the dash air/heat. The only thing not working right now is the dash air and Bendix cruise control.
As well I can't see the vacuum pump under the hood; it must not be belt driven and I can't see where it could be gear driven.
Soooooo... Is there a chance I have a vacuum gauge but no vacuum pump.
Otherwise what am I missing here?
THX

Stratosurfer, look in generator compartment for a small electric vacuum pump mounted to the left. At least that is where it is on a Gillig chassis.

Nick

It may look like this.

It does operate the HVAC flappers doors, and the cruise control.

Thanks guys, this is a big help as I was looking for an engine-driven unit. Nonetheless I have crawled around this coach extensively and have yet to see it.
Anyone have a Regency around my year who can tell me where to start looking. In the front grill area there is a pump but I'm fairly certain it's for the air horns.

quote:

Originally posted by Stratosurfer:
In the front grill area there is a pump but I'm fairly certain it's for the air horns.

You should not have a pump for the air horns. They should work off of the main air system that operates the brakes, etc.

Nick

Well OK then, thanks to you guys I believe I found my vacuum pump and will begin probing around to see why it's not breathing in.
Has anyone had to replace their pump: are these a time-failure item?
Next question, where on earth do I get one, I assume it's 12V.
Thanks all

See this thread. I have replaced mine with the smaller unit and it works fine.

Nick

The vaccuum guage on the dash aways reads 20# on ours when the engine is running. Never changes, stop and go, highway cruising, or sitting at idle speed. Everthing works as far as I can tell.
I'm presuming it is measuring engine vacuum but don't know that for sure.
A vacuum guage usually shows different levels of engine performance in a car, thats why it's used to show the best mpg while going down the road.
I don't get why it always shows the same reading on our diesel? Is something not right or is that how diesels work?
Don

Will a 12V PUMP work. I know a few guys that use 110V refrigerator/ small A/C pumps as vacuum pumps for evacuating auto A/C systems.
12V pumps are easy to find and could be adapted to be threaded on the intake side.
Just a thought if the pump turns out to be my problem.

quote:

I don't get why it always shows the same reading on our diesel? Is something not right or is that how diesels work?
Don

Now that I'm figuring all this out, it is an unloader switch that turns the pump on and off based on the vacuum on the vacuum 'rail'. If yours is steady then it should be working perfectly.
This vacuum gauge (I just found out) has no connection to your engine/engine performance, it performs coach functions only (oh and possibly cruise control).

There are a number of issues raised here that I just had to add 2 cents to. First - The diesel regencies use the secondary compressed air system for cruise control, the same one that powers the air suspension, steps, and wipers. A diesel will not produce vacuum for anything - that is why the auxiliary pump is needed for dash air. In some Regencies the original vacuum was created by porting compressed air through a venturi that created the vacuum that ran the dash ports. When it fails you can hear the constant hiss of escaping air, in my case under the front of the coach. The Bendix Cruise Control also operated on compressed ir but it suffered from electronic failure because it was exposed to the wheel and engine debris near the rear wheels. It can be repaired, but is not worth it. Cruise King Controls Inc. makes new direct replacements that are way superior to our originals. They do cost about $600, but why use 15 or 20 year old technology? I have been working to remove as much air dependent operations as possible because the air system is a single point failure that could be dangerous.

quote:

Originally posted by Tom K:
I have been working to remove as much air dependent operations as possible because the air system is a single point failure that could be dangerous.

Tom, have you converted the windshield wipers to electric?

Nick

The windshield wipers are pressurized air from air system, not vacuum correct?

Can they be replaced with electric??