I have an I/R 125kvw that will suck air and has to be bled every couple of days to start. So far I've replaced every fuel line and filter, to no avail. I'm in an isolated site so access to specialized tools is out. I ran it for 15 minutes yesterday morning; tried to start in the afternoon and no-go. All maintenance was completed prior to purchase, and the fuel tank was drained and cleaned.

When running it runs great; the only leaks I can see is comming from the H2O sep, which is more like seepage than a leak, and the return side of injectors 1 and 3.

I've tried RTV on all other fittings but nothing seems to cure it. Could the lift pump be going out?

 

Does it have a block mounted, diaphragm style lift pump? I've changed a lot of those for the same symptoms you are listing.

 

Yep. Has about 2900 hours on it right now; not sure if its ever been changed. Did you still have pressure comming out of the bleeder on the H20 filter even with that issue?

 

Yes, once primed they work but still pull some air. It looks like that pump had been changed before. Generally the original lift pumps are painted the same add the block, and new ones are unpainted. Is there only one filter on that system?

 

I bet there are 2 filters, one particulant filter and one h2o seperator

 

Pre filter before the lift pump.

 

If your sepperator is leaking that your problem I had a Heston 1380DT pulling air thru the sediment bowl, it was leaking and was causing loss of fuel...

 

An inline style, or an actual filter base with replaceable filter? If you do have a replaceable filter style, with a sediment bowl, check for an oring between the filter and sediment bowl. I have seem them missing many times as well. Makes for a very easy service call!

Some Deere equipment and OEM applications don't. I'm not sure why as it doesn't make sense, but they do. SG, SJ series backhoes only have the one, and no inline strainer.

 

Mine has a sedementer and H20 filter; both housings look original. I sealed all ports on the sedimenter with RTV and do not see any leaks comming from it (new filter/oring verified during acceptance inspection). The H20 housing, however, is cracked and will not allow the lock ring to fully seat; crack was sealed with RTV and threads were cleaned on the housing for the ring. Going to order one today and give it a shot.

The lift pump seems to be putting out great pressure when you pump the handle.