The Forestry Forum

General Forestry => Forestry and Logging => Topic started by: Rockvalley on March 15, 2019, 01:12:58 AM

Title: Cat 518 HELP SOS
Post by: Rockvalley on March 15, 2019, 01:12:58 AM
1993 cat 518 3304, starts idles runs great only notice the issue when pulling a load or climbing a hill. Not super steep either. It lugs the motor so far that you have to climb hills even empty in 1st and it still lugs when climbing in 1st like the motor won't stay in higher rpms. On flat ground empty its very quick. Changed air and fuel filters, checked vents on fuel cap. Cleaned screen under hand pump. Put new turbo on only a month ago that was no help. I think it has to be turbo or fuel related what else could be the problem. What's my next step? Anyone know how to check boost and also fuel pressure?
Title: Re: Cat 518 Pulling power
Post by: Riwaka on March 15, 2019, 04:07:39 AM
When was the last time the diesel tank on the skidder was checked for how clean the bottom is (is there a water drain in the bottom of the diesel tank?)? No little diesel bug sediments. Is there a screen on the diesel tank exit point. ?

How old is the diesel fuel pump? (or last overhauled) The pump getting fuel from tank to injector pump?

Any place air might be getting sucked into the skidders fuel supply line?


What is the diesel tank like that the skidder is supplied from?

Has there been any issues with the type of diesel that you use?


-----------------
Any leaks in the turbo pipes?


Title: Re: Cat 518 Pulling power
Post by: Rockvalley on March 15, 2019, 04:16:34 AM
Have not spent to much time looking at fuel system or induction. Wanted to be sure this is a fuel issue before I started blowing out line and trouble shooting. Anyway to check my pressure after the transfer pump? 
Title: Re: Cat 518 Pulling power
Post by: tacks Y on March 15, 2019, 07:42:20 AM
Maybe not pressure but check flow, maybe not enough?
Title: Re: Cat 518 Pulling power
Post by: log cutter on March 15, 2019, 10:37:36 AM
Did you check the fitting that the fuel line hook on to the primer pump housing? Needles can get caught that fitting and not make the 90 degree turn  going into the screen. 
Title: Re: Cat 518 Pulling power
Post by: Rockvalley on March 15, 2019, 12:01:19 PM
Am not there today am at another woods with a dozer. Tomorrow or Monday I will check the elbow on hand pump. How do you know if lift pump is shot? What's normal flow whats not enough flow. 
Title: Re: Cat 518 Pulling power
Post by: kiko on March 15, 2019, 08:53:57 PM
Any abnormal engine smoke when it pulls down. If so what color?
Title: Re: Cat 518 Pulling power
Post by: Rockvalley on March 15, 2019, 09:24:49 PM
Not really any smoke at all anytime running it
Title: Re: Cat 518 HELP SOS
Post by: mills on March 16, 2019, 03:57:37 AM
Have you had this skidder very long? Has it's performance dropped off, or is this typical operation for this machine? Reason is that 518's will pull a load, but tend to lug on hills. 
Title: Re: Cat 518 HELP SOS
Post by: starmac on March 16, 2019, 11:18:19 PM
There should either be a quick connect coupling or a port where one can be installed to check fuel pressure, and you connect a gauge to it, kind of like an air line quick connect. I do not have a clue what pressure it should have, on my E model I like to see 100 pounds at idle and 120 at 1500 rpms.

There will be a port some where on the intake side that a boost gauge can be hooked to also. Boost will not build in nuetral, it must be under load to build boost.
Title: Re: Cat 518 HELP SOS
Post by: GAB on March 17, 2019, 11:24:13 AM
What I know about skidders you can safely scribble on the back of a small postage stamp with a large sharpie.
However, I'd be checking the air filters.
GAB
Title: Re: Cat 518 HELP SOS
Post by: tacks Y on March 17, 2019, 02:24:02 PM
As GAB said, look at air filter. If it was in shop I would remove fuel line at pump. Add hose to it to a jug, remove fuel cap. Hold some rags on fuel tank and but air hose in to see flow. Do not blow up tank, with rags and air nozzle you should be fine. Then move closer to engine, bad primary pump?
Title: Re: Cat 518 HELP SOS
Post by: tacks Y on March 18, 2019, 08:05:01 AM
I would also remove fuel cap and blow air line back to tank.
Title: Re: Cat 518 HELP SOS
Post by: Taylortractornut on March 21, 2019, 12:33:59 AM
I used to keep up A 518 cutter and skidder compactor conversion for a landfill.   There's al lower. Primary screen below the fuel pump had a primer on it clean it out you may have to tak the lower side panel off to get to it.  IAlso ours in the ten years we ran them n get got all the last owners needles out of them even took the tanks out and steam cleaned. After you clean the filter screen and put in it replace take the lid off the fuel table and blow with an air hose back through the line that goes into the injector pump.  Then put the lid on the tank and blow back through the same line and take the air hose away it will reprime the system withought a bunch of hand pumping