Howdy guys We have an skytrak 5522 with a perkins 4.236. Machine had a few fuel issues that got addressed today. The fuel issues were that the machine would not run with out the bleeder being opened on the injector pump. WE figured we had a clogged return line and blew every return line out. That fixed the problem the machine runs with the bleeder closed but now it wont keep prime... The injection pump had a small leak from the top cover on the corner Now that the return lines are working can it be that the small leak on the top cover where the linkages are located is making the prime leak off? Machine runs great but prime leaks off after an hour of sitting. Any ideas would be great I was wondering if I can change the top cover gasket with out bringing it to a shop certified to do this work. Is this leak causing my prime to leak off ?? if I bleed the machine it would run again. arrow shows where the leak is located Thanks for your time guys
You can, and on the advice of a well respected pump guy who frequents this forum, you may want to use two gaskets to take care of any warp or imperfections in the top cover. I believe there is a thread with pictures or a youtube video somewhere showing the procedure.
Thanks I did find a video that explained the process I did not want to tackle this with out knowing what was inside. Do you think this leak is screwing my prime? The way I think of it air is getting into the system letting it not start.
I am not familiar with that machine, but if the tank sets lower than the injector pump, it's possible. As I recall there's usually a check ball in the outlet fitting for the return line which I believe is partly there to help maintain fuel in the pump, partly to create a bit of back pressure to insure the pump works correctly. There may be other areas where air can enter the system on the suction side, sometimes they'll run and pass a little bit of air on through, but lose prime when not running. Might try two or three psi of air in the tank, see if anything turns into a sprinkler.
It's been a long time since I did any tampering with this sort of thing but I think I remember there's no check valve on the delivery port, the fuel is prevented from running back by the valve in the lift pump. It wouldn't hurt to remove the lift pump and strip/clean/check it. Also, does it have a thermostart? (Glow plug thing that shoves a gout of burning diesel down the inlet manifold on cold days) I seem to remember these take their fuel from the return line and if faulty, can let air into the system.
Yes it has a thermostart I believe I damaged some sort of check valve when blowing air into the system . I think there is a check valve on the inlet of the injection pump but cant find an exploded view of this pump... Im looking to buy a rebuild kit for this pump any ways to fix the leak on the top cover and possible replace the check valve on the inlet if its really a check valve. all I found for an exploded view is this
So I found these. Monday I will be going to an diesel shop to see if they can order me a rebuild kit. Hopfefully it comes with the check valve parts . Today I opened injector 1 and 2 feed and it started Hopefully after these fixes it will not bleed off.
SO heres an update Yesterday after bleeding injectors 1 and 2 it kept prime after 5 hours . I left it over night and started it again today with no issues. That tells me that the check valve is working and the leak on the top cover is still letting air in but not enough to make it not start again correct me if im wrong. Any ways the leak has to be fixed because I hate leaks Tomorrow I hope to come home with a gasket.
fixed the leak on the injection pump ran great let it sit for 2 days and it would not start unless bleeding 1 and 2.... I guess Ill start replacing rings on the lines....