Can someone explain the purpose of vacuum hoses?

Question

You know how there are vacuum hoses which attach to the map sensor, fuel pressure regulator, etc. What exactly do they do, and how do they work?

What would be the effect of a small vacuum leak in one of the hoses, and could this leak impact the vacuum pressure in other hoses?

Thx for the info. This is on a motorcycle by the way...

Let's say I have a crack in the fuel pressure regulator vacuum hose, which is also causing the map sensor to thow a code for bad vacuum attachment. Would it do any long term damage to the bike to ride around on it for another week? Including some fairly hard riding tomorrow /w triple digit speeds.

Other than the map sensor code and a rough idle the bike seems to be running perfectly

Answer 1

engine ( intake manifold ) vacuum is an indicator of engine load under various throttle opening settings . this data is used in the various sensors to determine spark advance , cruise control settings etc. the engine management computer uses this signal in relation to other signals to determine proper fuel amount etc. if these hoses become cracked they will leak and mess up the whole works , even on non computerized cars.

Answer 2

Vacuum hoses are a source of energy for some components. Some fuel pumps work off of vacuum. Some sensors read vacuum pull & adjust the timing. If the engine is not running bad then it should not hurt it. Sometimes a broken vacuum line will cause the engine to run so bad you would have a hard time getting to double digits.

Answer 3

Yes, I use to teach diesel engines in the Navy and have been a mechanic for years. PCV means Positive Crankcase Vacume but some call it a Pollution Control Valve which removes explosive gases from your engine's crankcase. What would happen without it would be a build up of pressure and when your cylinders are at their exhaust stage, could possibly push sediment into your cylinders from beneath and even through the valve assemblies if pressure built up high enough.

I have never seen an engine explode but have heard of them catching fire because of the heat, pressure and churning oil in the crankcase.

Always check your oil level and replace the oil at or at least near the factory recommended mileages. Especially with synthetic oil because if synthetic oil breaks down, it is definitely explosive and could do a whole lot of harm. (No, I am not talking bomb but damage just the same.)

Many components work on a vacume. Navy air compressors will shut down if vacume is lost and utilizes that vacume to activate certain regulating switches, valves and other components. Sometimes fuel is shut off at a loss of vacume because you definitely don't want to add fuel to a possible fire.... If you know what I mean. I remember this old Ford Thunderbird that had power windows, brakes and everything else that worked on a vacume. It is actually far safer than using pressurized lines and lasts a whole lot longer.....

I hope that answers your question

Answer 4

they suck

yes a leak in one hose means lower pressure in the manifold which would affect all the hoses

if it is a small leak you might not notice it on the things controlled by other hoses though

Answer 5

Give horse back riding lessons. Talk about proper care of the horse, how to mount and go fast, slow etc.