0ld gradall fuel issue

[Mobilewrench]

Ran into a strange fuel problem on a gradall with a Perkins engine last week.

 

[Mobilewrench]

Not great pictures.

Anyway, standard crank/no start. Looks like someone else was trying to figure it out before me because there was a box for a electric fuel pump and 2 old fuel lines on the seat.
Checked fuel level and that the pump they installed was working and correctly plumbed. Cracked a couple of injector lines and cranked the engine to bleed the air out and it fired up. But died before I got the lines snugged back up. Did the same thing two or three more times with the same result.
I started to think that the injection pump was bad.
I took the feed line off of the injection pump to get an idea of the volume of fuel through the filter. This is where things get weird.

Activated the lift pump and no fuel came out of the filter housing. Instead it came out of the injection pump. I bypassed the filter housing and it fired up.
Why is my fuel flowing backwards? I have never run across a filter so clogged that it pushed fuel into the return side and it didn't look to me like they could have swapped the hoses when they changed them.

Is there something wrong in the filter housing?

 

[skata]

I'd look at or change the fuel hose going to the tank. As they age, I've seen them collapse internally and not allow fuel thru

 

[Mobilewrench]

Thanks, but that was one of the hoses that they already changed. And I have fuel flow all the way to the filter thread.

 

[funwithfuel]

Check for debris in each elbow and banjo. Run alternate fuel source for supply and return. ie, bucket o fuel. Also, check them little rubber compression sleeves Perkins and CAV are so famous for. Make sure they didn't deteriorate. These are a few of my favorite things. Good luck

 

[thepumpguysc]

Does that unit have the 3 pc filter set-up with the long bolt holding it all together.??
Check that top oring.. MAKE SURE it’s UP IN the filter head..
Someone else mentioned the “OLIVES” in the inlet and return.. they’re also in the filter head end.. don’t overlook them..
How about the filter under the inlet nut..
To check it, remove the inlet nut, remove the big spring..
HOLD THE GUTS DOWN WITH A POCKET SCREWDRIVER.. and with a 90* pick, dig out the plastic filter..
Hope this helps.

 

[Mobilewrench]

Does that unit have the 3 pc filter set-up with the long bolt holding it all together.??
Check that top oring.. MAKE SURE it’s UP IN the filter head..
Someone else mentioned the “OLIVES” in the inlet and return.. they’re also in the filter head end.. don’t overlook them..
How about the filter under the inlet nut..
To check it, remove the inlet nut, remove the big spring..
HOLD THE GUTS DOWN WITH A POCKET SCREWDRIVER.. and with a 90* pick, dig out the plastic filter..
Hope this helps.

I believe it is the filter you mention. I was wondering if they changed the filter and neglected to put that in.
I didn't see any joints with umbrella seals. Is that what you are calling olives? Just compression fittings. Believe This is the filter head.

 

[Mobilewrench]

Also checked the inlet filter on the injection pump.

 

[thepumpguysc]

On that filter set up, the top oring MUST GO UP IN the filter head.. a lot of times it’ll either fall ON TO the filter or it’ll be placed on to the top of the filter.. it “looks like”’it goes ON THE FILTER but it doesn’t.. it goes UP IN the groove in the filter head..

 

[Mobilewrench]

Thanks, I will check it out.

 

[Mobilewrench]

You called it.

 

[Mobilewrench]

He actually had one installed in the filter and one in the filter head. And an extra oring in the sediment bowl.
Can't say that I blame him. The access to that filter is pretty poor on that machine. It was all mirrors and Braille.

 

[thepumpguysc]

Kool…
Good find.!!!
Stick with me kid.. I knows me some sh!t.. lol