l1501 cam shaft plug replacement

[Daren Todd]

D2cat had asked me in a previous post how I replaced the cam shaft plug. And hopefully this will help out some other folks here as well. I happened to get this little beasty from my father in law. When I got it there was a few issues I noticed off the bat. Wasn't charging right, oil pressure sensor was disconnected, had a push button starter switch added to it. I spent a Saturday tracing out and fixing wiring. In the process I found wires shorted where they run to the horn, clutch safety switch, and the glow plugs. The wires crossed over to the other side of the motor between the engine and fuel tank heat shield. They ended up getting melted down and stuck to the engine block. For those guys who have a l175, l185, l1500, and l1501, plus a few other models. There is enough slack in thew wiring to move it behind the heat shield. Hooked the oil pressure sensor in the process to see if it worked after the wiring was fixed. light came on and stayed on. I brought home my test kit from work, tested the oil pressure off the plug on the oil filter base and only got about 15 psi. So I started searching this forum and found the service notice pertaining to the z750a engine. And then read the post's from the guys that had done this repair. Found the parts manual at www.kubotabooks.com, and got the service manual from www.kubota.servicemanualvault.com.
I started out by removing the radiator and fan shroud. It's not required to remove the front end, but in my case I wanted to flush it also. Jacked the tractor just behind the oil pan, leaving enough room for jack stands, and just enough to take the pressure of the front end. Removed the five bolts for the front end, and disconnected the steering linkage. Then rolled the front end out of the wayhttp://www.orangetractortalks.com/forums/attachment.php?attachmentid=11720&stc=1&d=1401570384
Then on to tackling removing the crank case cover. I removed the nut on the crank shaft using a 2 foot pipe wrench on the front pto shaft and a 1 7/8 wrench on the nut. And with some pressure applied the nut came right off, and no damage to the pto shaft. I know someone will chime in bout proper tool for the job Couple of heavy pry bars and a little wiggling from either side and the drive pulley came off. removed the alternator to get it out of the way, and removed the fan as well. Pulled the outer bolts that held on the crank shaft cover. The larger bolts are the only ones that need to be pulled. the smaller nut and bolts on the water jacket cover only need to be removed if you plan on accessing the water jacket. And then the fun part of talking the gasket into giving up and allowing the gear case cover to be removed. You also have to disconnect the throttle linkage and plate that bolts to the top of the crank case cover. The inspection cover for the injection pump. Carefully remove the spring that attaches to the throttle linkage, and a small spring that attaches to the crank case cover. A curved set of needle nose pliers works best from the springs. Wiggle the cover back and forth and eventually the gasket will give up and allow you to remove the cover. Total time to get to this point was about 3 hours. Plan on another 4 hours scraping gaskets. Here's some pics, gotta go get the grand kiddo. So will finishg the rest later on http://www.orangetractortalks.com/f...ent.php?attachmentid=11722&stc=1&d=1401572618

 

[Daren Todd]

Spent about 4 hours scraping gaskets, and getting everything cleaned back up. And i got lucky with the cam shaft plug. It was the front one, and since the motor started good, no oil leaks, And no signs of a blown head gasket i decided to just replace the plug instead of doing a complete tear down of the motor. I ordered the camshaft plug, crank case gasket, collar, o'ring for the collar, 3 o'rings for the oil ports on the cover, and a new lip seal. Tapped out the bearings for the fan, and went to the local bearing shop and got replacements. The o'ring that goes around the water jacket is a common sized o'ring, so i was able to match it out of an o'ring kit that i had. I went ahead and made the gaskets for the inspection cover, oil filter housing, and throttle linkage cover with a paper gasket kit from the local auto parts store. Got the kit that had the same material as the crank case gasket.
To install the camshaft plug, I cleaned up the end of the camshaft with a shop towel soaked in acetone and got inside the camshaft as far as i could as well. Wiped the camshaft plug as well to make sure any oil was off from it. Coated the plug in high temp/ high strengh loctite and tapped in with a brass punch. Then let it set up while i was waiting for my parts to come in.
To reinstall the crank case cover, i tapped in the bearings for the fan and lip seal using a bearing, race, and seal kit. Made short work of it gave the crank case cover a skim coat of black rtv to hold the gasket in place. Lined the gasket up with the holes. Also put a small dab of rtv where the o'rings go for the oil ports, and placed the o'rings as well. Installed the o'ring for the water jack, and collar. Then mounted the crank case cover. Installed the collar being careful to mess up the lip seal. Installed the pulley, washer and nut. Tightened the nut, bent the washer back over to lock the nut. Attached the spring to the cover, then the spring to throttle linkage. Reinstall the oil filter base, inspection cover, plus the rest of the stuff on the front end. Added radiator hoses, and a new fan belt as well.
I ordered a new hour meterer as well since the old one was stripped out. Now kubota doesn't make one for that motor anymore. Didn't find that out till after the new one got here and the end was machined down smaller then the original. The bolt pattern and shape are the same. The shaft size where it's round is the same as the original though. I took that to the local machine shop and had them make a sleeve for it to get the end back to the proper size. The sleave was a press fit, and installed with some more of the high temp/ strengh loctite. Mounted the new hour meter. Topped up the antifreeze, changed the oil leaving the old filter still on it. Swapped out the oil pressure sensor with one that takes a minimum of 35 psi to activate it. Now to fire the old girl back up and see how everything hold up. Preheated the engine for 15 seconds, hit the key, and fired up on the second crank. Runs quieter, no smoke, no leaks, and the tack works and it has oil pressure now. Ran her for fifteen to twenty minutes, dropped the oil and changed the filter.
As far as we know that little bota has been running for the past 10ish years with low oil pressure. Kubota definitely builds some bullet proof motors

 

[Daren Todd]

here's a pic of the beasty back together

 

[Daren Todd]

Update
Mother Nature finally cooperated and was able to get the old girl out and run her for a couple hours today. No issues, ran like champ

Thanks wolman for helpings locate the parts


Sent from my iPhone using Tapatalk

 

[meanjean]

Thanks very much for the great post.
Looks like I will be doing this job myself and I will refer to this.

 

[Daren Todd]

Your welcome, kubota might give an issue bout the gasket on the crankcase cover. The only difference between the 2 gaskets is an extra hole for an oil port that wasn't used on mine. In my case after laying it out, i just snipped the extra port out so it wasn't flopping around inside the cover.