2nd Gen Non-Engine/Transmission fass cavitation please help what do i do

[VHolloway]

do we need to have someone drop the tank and put in a bigger pick up tube???

I hope that will fix the noise

 

[WTBurke]

Sir,

With limited information such as this... do you have an air leak? Sucking air at the feed point will cause cavitation?



William

 

[VHolloway]

no it just started raising hell the last day or so we had the muffler removed so we had a hard time hearing it



when we had the fass II pump put in at cummins they did not put a biger pick up tube it's stock

i hope this is whats wrong

how hard is it to put in a bigger pick up tube

we where filling the tank with fuel when we heard it

 

[VHolloway]

just checked fuel psi 13 at idle

15 psi when you bump the starter

I was using a geno's fuel pressure tester hose this was on the filtered side of the

test port

that pump is really making some noise

 

[DEdwards]

Noise does not mean cavitation. Time to do a little diagnosis.

1. How old is the pump?

2. Are there any isolation mounts between the pump and frame?

3. Did something get pushed around under the truck where it can touch and telegraph noise?

4. Are you sure it isn't just normal noise? FASS pumps are not as quiet as stock or walbro pumps.



Just my . 02 worth, it isn't a real good practice to leave the truck running while fueling. And the pump will sound really loud echoing out the fuel filler even though it's not in the tank.

 

[VHolloway]

the truck was not running when i was putting fuel in.

i bumped the key to make the pump run so I could hear if that was the noise

after i added fuel

we need the truck it's our only car we have

I never had time to put in a fuel pressure gauge

I had a geno. s vulcan fuel pressure test kit I ran it thru the fire wall

for a temporary set up

untill i can get a gauge put in

I have had this fass a almost a year and never had a problem

i know what it did sound like and this is not rite

ps. I just put the genos gauge in today to get me by

 

[VHolloway]

we will keep a eye on the fuel psi its at 13-14 at idle on after filter side

this thing sounds bad

I called daves diesel they sold me the pump and cummins did the install

I hope this pump is OK

 

[steved]

we will keep a eye on the fuel psi its at 13-14 at idle on after filter side

this thing sounds bad

I called daves diesel they sold me the pump and cummins did the install

I hope this pump is OK

Does the noise cycle (up and down) or is it steady???



If it is cycling, then I would assume it is cavitating and harmless. Mine has done it since new and it also depends on the fuel... some fuel does it worse than others... I currently have over 50k on my FASS with it making the cycling cavitation noise.



If it is continuous, then I would suspect a possible bearing...



steved

 

[VHolloway]

The Best Way I Know To Tell You Is The Sound Goes Up And Down But

It Sounds Like A Bearing

But It Keeps Good Fuel Pressure

 

[steved]

The Best Way I Know To Tell You Is The Sound Goes Up And Down But

It Sounds Like A Bearing

But It Keeps Good Fuel Pressure

Sounds like it is simply cavitating... I would give it a few days (and a couple tanks of fuel) before I got worried...



As I said, mine will do it continuously, just depending on the fuel I have in the tank at that time... other times it will be completely quiet...



steved

 

[VHolloway]

I HAVE NOT ADDED MMO AND POWER SERVICE i RAN OUT

A TANKS OR SO BACK

THE TRUCK LOVES THAT STUFF IT RUNS REAL SMOOTH

PLUS I WANTED TO SEE HOW IT RUNS WITHOUT IT

I NEED TO PUT SOME IN AND SEE

SOME PEOPLE WOULD THINK I ADD TO MUCH

BUT I BEEN USING IT FROM THE TIME I GOT THE TRUCK

 

[WStephens]

Cavitation will distroy a pump, it is caused by air bubbles exploding and will eventually errode the pump until it is distroyed.

 

[VHolloway]

WE WENT GOT US SOME MARVEL MYSTERY OIL WE ADDED MMO MY WIFE DRIVES IT TO WORK AND CALLED TO SAY IT'S BACK TO THE OLD BUZZ NOISE

MY EYES SIGHT WONT LET ME DRIVE SHE DRIVES THE BIG 2500 4X4

LIKE A OLD LADY NICE AND SOFT MAN i WISH I COULD SEE TO DRIVE

SHE WILL NOT EVEN PUT HER FOOT IN IT EVEN IF I ASK

THE TRUCK STRIGHT PIPE WHAT A SHAME

Oo.

 

[steved]

Cavitation will distroy a pump, it is caused by air bubbles exploding and will eventually errode the pump until it is distroyed.

According to what I have read DPP state, it wouldn't hurt the gear pump design they use... ?



VHolloway: So you figured out it was nothing more than a change in fuel?



steved

 

[VHolloway]

ultra low sulfur diesel fuel also as S 15

my wife told me she filled the tank with this fuel. but the marvel mystery oil in the tank over night did the trick.

she called me when she was doing the cool down at work

and told me it was back to the old buzzing sound

when she gets home I will check it out

I shore hope everythig ok

we love this truck









































0

 

[LowFly]

Tagging this thread... . ill get back to it here in a bit... . busy day at the shop.....

 

[VHolloway]

It's Strange When I Added The Marvel Mystery Oil It Seem To Slowy Go Back To The Oil Buzzing

I Add The Small Bottle Mmo At Fill Up It May Be To Much Oil It Seems To Like It The Injection Pump Stops Ticking