Jump to content

856 Fuel Pump


schoolman
 Share

Recommended Posts

My 856 with a 407 engine had a leak at the pump. I decided to remove it and get it rebuilt since it had a lot of hours. I removed the front plate and took the nut off the drive shaft. I wired the throttle open. When I removed the pump, the shaft stayed in the drive gear. Do I need to take this shaft out to take to the rebuilder? Is there anything else holding the shaft other than the nut on the end? Thanks for any help.

Link to comment
Share on other sites

Be sure to replace the 2 seals inside pump mounting to drive assembly. Or you will have fuel in crankcase

Slick

Link to comment
Share on other sites

4 minutes ago, Slick1256 said:

Be sure to replace the 2 seals inside pump mounting to drive assembly. Or you will have fuel in crankcase

Slick

The seals are on the pump drive shaft, not inside the pump.  Have to be careful installing the pump over the new seals.  Easy to damage the new seal. 

Link to comment
Share on other sites

5 minutes ago, J-Mech said:

The seals are on the pump drive shaft, not inside the pump.  Have to be careful installing the pump over the new seals.  Easy to damage the new seal. 

Guess i should have worded that differently, the point was theres 2 seals that need to be replaced before reassembling the pump

Slick

Link to comment
Share on other sites

1 hour ago, J-Mech said:

The seals are on the pump drive shaft, not inside the pump.  Have to be careful installing the pump over the new seals.  Easy to damage the new seal. 

The seals on a 361/407 are in the drive housing, so it is not possible to roll them when installing the pump.

But I do agree, they need changed when the pump is off.

Link to comment
Share on other sites

11 minutes ago, pirlbeck said:

The seals on a 361/407 are in the drive housing, so it is not possible to roll them when installing the pump.

But I do agree, they need changed when the pump is off.

Thank you, my point exactly. Was just trying to help a guy out. Been there, made that mistake knot on my head i remember. 

Slick

Link to comment
Share on other sites

14 minutes ago, pirlbeck said:

The seals on a 361/407 are in the drive housing, so it is not possible to roll them when installing the pump.

But I do agree, they need changed when the pump is off.

After you said this, I admit I had to go look.  That's correct.  I was thinking of the two opposing umbrella seals used in other applications that are on the shaft.  But correct, the 361/407 has the seal in the drive housing.  My mistake.

Link to comment
Share on other sites

so being the seal arrangement is different and there were conflicting comments.

Op question should the shaft have went to shop also?

is there a different install tool for this model?

no tools/tips required ......lube and slide it back on as is??

Link to comment
Share on other sites

When I rebuild a 361/407 Roosa pump, I have them send me the drive adapter too, I clean it up, polish the shaft, and replace the seals at no additional charge as long as it comes with the pump. I also provide the mounting O ring and the access cover gasket. Many people mess these seals up in installation. The drive adapter is a Roosa Master component. I've had people loctite the bearing so it wont slide back and forth. Well, that was a bad idea, he got to take it all apart to clean it up, the pump wouldn't slide all the way up. Of course he had to call me and ask what I put together wrong in the pump. The shaft floats, and is set by the thrust bolt on access cover. Don't mess with it, you'll be fine as long as you replace the gasket after removing the old one thoroughly.

Oh, it's very unusual for these seals to just leak on their own without being caused by an internal pump issue. If it hasn't been apart in ages, and the seals are putting fuel in the oil, the pump is likely due for service!

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...