What would cause a blowers lift to fluctuate???

[jcooper]

Soooo yea, blower lift is fluctuating on a job to job basis.

One day I'll fire it up and my lift(hand over vac inlet) will go up to 14. Next job, it might only go up to 10, my vac relief won't even open at 10!!

I did replace my blower belts about a month ago, it's got to be a belt issue? Right? Somehow slipping? Should I keep tightening?! If I had to guess maybe a 1/4 - 3/8 or so, of play. Is that too much?

Blower already seems like it's higher on the bolts than before belt change. This normal?



I've replace my waste tank seal, no air leaks. Vac relief seems to be working fine, if I can get enough suck to open it!

Thanks fellas...

 

[Nate The Great]

Your gauge could be bad also.. I've put a vac gauge directly on my waste tank and watch it go to 16-17" while operating it...

I got more leaks than the Clinton's scandals...

 

[jcooper]

Yea, it's not the gauge. Definitely having some vac loss.

 

[Desk Jockey]

Engine sounds steady or is it fluctuating also?

 

[SamIam]

Hose leaks?

 

[Nate The Great]

Hose leaks?

Don't bring Bawb Vawter in this....!

 

[jcooper]

Engine sounds steady or is it fluctuating also?

Other than it's a pos Kohler, seems to run normal.

Hose leaks?

Nope.


Today I loosened all my blower bolts super loose, re raised the blower, making belts as tight as I could with in reason.

Full throttle - hand over vac inlet it goes to 11 and no more. Vac relief does not pop.

If I back out the relief it will pop, but my vac is super low.

Any ideas?



Guess I should get some new belts? Is it possible to stretch them?

 

[Jim Martin]

if you are sure that you have the correct belts on it and they are seated down into the grove of the pully correct...
and they are tight..but not over tightened...

and the engine is a steady sound to it and is not fluctuating in any way...


then I would take the vac relief off and clean it really good and reset it...that would be the first place I would start...

 

[SamIam]

Ya it’s probably vac relief problem

 

[Desk Jockey]

We've had that with the older Nissan's as the governor wore out and engine wasn't maintain it normal operating speed.

 

[SamIam]

Did you cover all the holes on the vac relief?

 

[jcooper]

Did you cover all the holes on the vac relief?

Yea, couldn't feel any air racing past it.


If I back off(loosen) the relief it will/does work. But my vac/lift will end up way to low(like 8).
So I've got the relief valve pretty tight just to get up to 11 on the gauge.

It also seems like the issue is intermittent, one day 11 on lift next time 14.


Seems like it has to be belts.

if you are sure that you have the correct belts on it and they are seated down into the grove of the pully correct...
and they are tight..but not over tightened...

Think I have little more than a 1/4 inch of play(push/pull on the belt). Should they be tighter?

 

[SamIam]

Yea, couldn't feel any air racing past it.


If I back off(loosen) the relief it will/does work. But my vac/lift will end up way to low(like 8).
So I've got the relief valve pretty tight just to get up to 11 on the gauge.

It also seems like the issue is intermittent, one day 11 on lift next time 14.


Seems like it has to be belts.




Think I have little more than a 1/4 inch of play(push/pull on the belt). Should they be tighter?

Like Jim said clean it!
I’ve sprayed mine with wd40 on my old 405 when it was acting up and tightened it up to 15 hg and every now and then acted up.

Wd40 helped.

 

[steve_64]

Filters?

 

[Shane T]

Have you cleaned the blower filter? Don't just clean off the outside, soak it in hot water with detergent and then flush.

 

[BIG WOOD]

I keep my belts on 1/8” of play

 

[jcooper]

Yea, filter all seem fine.

I keep my belts on 1/8” of play

Well... maybe that's my issue. I've got at least a 1/4" plus.

Tighten crap up more and lube the poop out of my relief valve.

If that doesn't work, I'm going to have to go see the dreaded disty...

Thanks again, fellas.

 

[Shane T]

Yea, filter all seem fine.

Probably wouldn't cause an intermittent problem but dirty filters can be subtle. I run my unit with a Devastator inline filter and panty hose over the blower filter and replace it when it gets dirty. A couple years ago when I was having a reduced vacuum I found that the blower filter had become laden with caked on fine soils. I think it was a combination of moisture and fine dust that made it through the panty hose. It took a fair bit of soaking, scrubbing and flushing to get it clean. I now take it off and look to see if light gets through it.

 

[SamIam]

Probably wouldn't cause an intermittent problem but dirty filters can be subtle. I run my unit with a Devastator inline filter and panty hose over the blower filter and replace it when it gets dirty. A couple years ago when I was having a reduced vacuum I found that the blower filter had become laden with caked on fine soils. I think it was a combination of moisture and fine dust that made it through the panty hose. It took a fair bit of soaking, scrubbing and flushing to get it clean. I now take it off and look to see if light gets through it.

Dirty filters will cause you to lose lift at the wand, the machine gauge will be running we’re its set. 12-14 hg

Dirty filters are just like blocking the inlets

The more they’re blocked the less airflow and your lift gauge goes up.

 

[Shane T]

Dirty filters will cause you to lose lift at the wand, the machine gauge will be running we’re its set. 12-14 hg

It depends where the relief valve is positioned. My relief valve is on top of the tank so it shows the vac level in the tank not at the blower.

 

[Mikey P]

So what's the verdict Jerry?

 

[Dolly Llama]

it's not the belts
a blower spinning at low RPM still pulls the HG you set .
You lose CFM and it takes longer to evacuate air to HG setting , but it will still come up (or stall your engine) which ever occurs first

you say its intermittent
My Magic 8 Ball suggests a loose tank lid that seals/sucks down sometimes but not others
or some air leak that heat/cold or half full tank effects it


does it go away after TM is hot (second/third job of the day) and or half full waste tank?

..L.T.A.

 

[steve_64]

I smell the belts getting hot when it's running good. Slipping that much I would think you would smell it.

Filters can unplug somewhat between jobs. Gravity and aggitation from the road but it doesn't sound like that. I'd tighten up the relief and see if that makes any difference.

I thought you had this problem not long ago? Maybe it was someone else.

 

[jcooper]

So what's the verdict Jerry?

Still perplexed...

 

[SamIam]

Still perplexed...

Like Larry Larry said could be lid even though you said you just replaced it

 

[Jim Martin]

there really is not too many things in this area that can go wrong....

Belts are not gripping...
something is plugged...
lid gaskets are not sealing...
relief valve needs cleaning...
you may need to add a washer or 2 to the relief spring to tighten it up some...
the engine may not be firing the way it should or a fuel issue and its stumbling...

even though you have...changed...check....replaced...or adjusted... and the problem is still there...then go back and look again..have you taken the belts off and ramped up the engine by its self to see how it sounds and if it is running smooth....does it sound the same at idle and under a load...

 

[Shane T]

Since I don't know what model unit you have this may not apply but mine came with a tube and coil style blower exchanger. The coil began to move around with the air movement and would eventually block the discharge side which really effected the vacuum. Check the heat exchanger and silencer.

 

[Jim Martin]

Since I don't know what model unit you have this may not apply but mine came with a tube and coil style blower exchanger. The coil began to move around with the air movement and would eventually block the discharge side which really effected the vacuum. Check the heat exchanger and silencer.

yep....good point...one I did not think about...the HX could be plugged and it may be back lashing...

 

[Mikey P]

SS370