Bobcat 520 project

[WhathaveIdone]

I was bored so a friend of mine had a 75/76 bobcat 520 sitting in his yard for approx 10 plus years. Original kohler k582 engine was burnt up due to no oil pressure. So. I was bored. It is now in my garage. Lol. Told you I was bored.

I pulled the engine, cleaned all the mice nests out etc


Thinking about repowering with the Honda repower kit. Additional power from the original motor. Anybody have experience with this?
Issues? Tricks?

Needs a couple of hydraulic hoses and tires.

Will probably have more into it than it is worth but I now have a small skid steer.

 

[WhathaveIdone]

Right now I pulled the original engine

 

[groundcover]

Not a bad looking rig ! Have fun and keep us posted.

 

[WhathaveIdone]

Not a bad looking rig ! Have fun and keep us posted.

No not bad as fas as I think. I know nothing about these things. I am mechanically inclined after restoring and rebuilding cars but this is a different animal. Life long learning is my moto. I learn by doing and getting advise from people much more knowledgeable in things. I then pass on what I have learned.

I will send out pics as things progress.

 

[WhathaveIdone]

View attachment 681559

 

[WhathaveIdone]

Looking for advise as to what I should be checking prior to engine install. Just do not want to install something just to rip it out again.
Not much info on the 520 on the site.

 

[6thgpSF]

Looking for advise as to what I should be checking prior to engine install. Just do not want to install something just to rip it out again.
Not much info on the 520 on the site.

Facebook has a group for these older Bobcats russ

 

[lilranch2001]

I would venture a guess that you would want to replace any rubber items in the engine bay that is looking tired, I have worked on a couple bobcat hydraulic systems and they are no fun fighting the engine

 

[WhathaveIdone]

Yes - have replaced two hydraulic lines that lead to the cooler as they were cracked and rotten.
I have decided to pull the overhead cage and take the fuel tank and hydraulic oil tank out and clean them out. looked inside and was not happy with what I saw.
Also looked inside the chain case. All seems ok. One chain is looser than the other. Going to clean this out also.
With cage removed certainly makes things easier to get at.
Well it certainly is morphing into more but what the heck. I told you I was bored.
I haven even ordered the engine yet!

 

[WhathaveIdone]

Been away for a while and finally got back to the machine. Just to update everyone who is watching. Lol
I have ordered the repower Honda 630 engine. Should be here next week. Purchased kit from repower specialists. Will advised how kit is.
Removed hydraulic oil reservoir tank and found several pin holes in the tank. Now I know why all the hardened oil in the bottom of the machine I cleaned out came from. Sealed up the tank and will paint with some rust paint.
Removed the fuel tank and cleaned it out.
Replaced two hydraulic lines that were obviously rotten leading to the cooler in the rear door.
I am going to completely redo the wiring and new controls for lights, gauges etc.
Will get pics as thing progress

 

[Xfaxman]

Good luck

 

[WhathaveIdone]

Hi gang. Just picked up and unpacked my engine repower kit today for my Bobcat 520. Took a while to get it across the border but so far impressed. Here is some pics of the unboxing.

 

[WhathaveIdone]

Comes with just about everything. New throttle control, choke control and cables, bolts, exhaust, wiring diagrams, installation instructions. One thing I can see is possible an extension on the exhaust tip to exit the cab. Will see as I progress.
I have nothing but good things to say about this company so far. I asked all kinds of questions and if the salesman didn’t know he had people call me that did. Definite good customer service.

 

[WhathaveIdone]

Ok everyone the engine is installed. Not a bad job and the instructions for are good. Electrical instructions are also good.
Started up today. Final adjustments needed but running.
When I started it today the bucket immediately began to lifted and had to shut it down before I put the bucket through the garage door. That was close! Lol. Panic mode set in and my wife was filming it. Not my best!
Pump making noise. Whining noise.
Have to hold the peddle down to keep the bucket from raising. Will not lower but leaks down. Bucket will not move either.
Will move forward and backwards

Any advise? Or am I heading into a pump rebuild?
Remember this unit had been sitting for many years.

 

[WhathaveIdone]

I have to modify the rear door fan shroud. Although in the picture it does not look like it but the engine sticks out a bit. Hence the reason for the modification to the rear door shroud.

 

[WhathaveIdone]

One other thing. Feels as if the engine is under increase load when running. I throttle down and the engine will die.
Iam wondering if I should remove the relief valve, inspect clean and reinstall?
I have not touched the hydraulic system other than clean out tank, two new hoses, new filter and new hydraulic oil.

 

[WhathaveIdone]

Ok everyone. Having lots of issues with the hydraulics. Want to rebuilt the control valve but unfortunately the seal kit is not longer available from bobcat. Contacted the dealer and even they will not look at the machine.
I have found the arm and bucket cylinder seals aftermarket on line but not for the control valve. Any assistance would be grateful.

Now that the hydraulic system is full of fluid and air out of lines the engine will not turn over. The direct set up to the pump just wants to pump the fluid but there is no relief. (Relief valve seized??????) The dealer indicates the system is "Dead Heading" in otherwords the fluid is not going where it needs to go when the system reaches pressure.

Any recommendations on parts or what to do please advise.

Thanks in advance.

 

[crashz]

Check the Skidsteer forum, they can help on parts and the hydraulic issues. A lot of guys fixing up old Bobcats on that site.

Can you get the valve body to return to neutral? Seems like the bucket controls are constantly on. Maybe a stuck valve?

 

[6thgpSF]

as I said earlier,Facebook has a group on these older bobcats, and guys have advice and parts and sources for these machines....russ

 

[Spitzair]

Sorry I’m a bit late to the party here but have you checked that your auxiliary hydraulics are not engaged? I haven’t been around a 520 before but usually The right steering lever on these vintage machines is also the aux. hydraulic control. It has a detent all the way to the right to run attachments that need constant flow ie. backhoe or sweeper. Pull it to the left and see if it pops out of detent. When they are in detent with no attachment hooked up the fluid deadheads against the quick couplers and has nowhere to go. Usually this results in the lift arms going up and not coming back down. If your control lever doesn’t move left or right you can also run a short length of hose between the two aux couplers and see if that helps any. There may be a lockout bolt installed in the right lever to prevent the auxiliaries from being accidentally engaged and perhaps the linkage rod could be bent or out of adjustment engaging the spool... just some simple things to check...