Why will my bucket not curl, Cat 416c?

[rutwad]

Cat 416C TLB bought used. The FEL originally seemed weak when I tried curling the bucket with almost anything in it. Now I think it's more of a control problem. Sometimes it won't even attempt to curl. Any common issue with these Cats? Any ideas on fixing it?

Thanks, to all my Heavy Equipment Heroes!!!!

 

[grandpa]

take one of the lines off the cylinder and put it in a bucket and try it, if you got good flow, maybe its in the cylinder seals. if no flow maybe control issues.

 

[oldseabee]

Could also be a circuit relief, put the bucket flat on the ground, then activate the bucket dump, it should lift the front of the machine. If it is weak in only one direction, probably not the cylinder, but the valve cracked, or circuit relief bad.
Bottom out the curl cylinders and check the pressure to see if it is in spec.

 

[Lee-online]

Resolver has a cut or blown o-ring. very common problem.

 

[rutwad]

Resolver has a cut or blown o-ring. very common problem.

I hope very common problem equals easy fix. BTW, what is a resolver?

THANKS!!

 

[jimg984]

in North Carolina its pistol lmao

 

[Lee-online]

I hope very common problem equals easy fix. BTW, what is a resolver?

THANKS!!

The resolver sends signal oil to the pump to upstroke it. The primary resolver resolves the work port pressure from either the head or rod end. The secondary resolves between the different sections of the valves and don't cause too many problems. When a primary resolver seal blows it actually connects the head and rod so you loose power or have no power. Drift is also a problem.

It is easy to get to. On every valve section on the bottom there is an Allen head plug. this is the resolver. unscrew it and pull it out. it is about 3" long with a seal on the threaded part and two seals and a backup ring on either side of the ball. the plug is small, about the size of a dime and i think takes a 5mm allen wrench.

when they go bad i replace the whole resolver (about $50) but the seals can be replaced also.

Hopefully this helps.

 

[rutwad]

The resolver sends signal oil to the pump to upstroke it. The primary resolver resolves the work port pressure from either the head or rod end. The secondary resolves between the different sections of the valves and don't cause too many problems. When a primary resolver seal blows it actually connects the head and rod so you loose power or have no power. Drift is also a problem.

It is easy to get to. On every valve section on the bottom there is an Allen head plug. this is the resolver. unscrew it and pull it out. it is about 3" long with a seal on the threaded part and two seals and a backup ring on either side of the ball. the plug is small, about the size of a dime and i think takes a 5mm allen wrench.

when they go bad i replace the whole resolver (about $50) but the seals can be replaced also.


Hopefully this helps.

Lee, I want to make sure I have the right thing. The allen head had a lock nut on it. Took them off. Alen head thingy was about 1" long, came to a point, and was topped with a spring. This was under the valve near the front. Toward the rear I noticed a similiar item, but a little larger. It had a screw-slot instead of allen head. Took it out, it was about 3" long, spring set in end followed by a small metal ***.

I was looking in a parts book and did not see the items that I pulled. Just wondering what you thought, and many many thanks. We have been dealing with this bucket for 1 year, so hopefully this will get 'er fixed!!!

 

[Lee-online]

The plug is flush or recessed, maybe partially covered by the end cap. It is directly on the bottom pointing down.

#33 is the resolver. (circled)

 

[rutwad]

Thanks!!!!!!!!!!!!!!

 

[rutwad]

FOUND IT!!!!!

From where I was, the resolver was hidden just under the edge of one of the caps, behind it, and under lots of crud!

NOW, swapped for new resolver and reassembled. The bucket will not curl at all now. As a matter of fact, as soon as I lift the loader arms the bucket will dump just like I am dumping it. The only way I can roll it back to level is by placing it on the ground and backing up while letting down the arms and placing the lever to curl.

Just found out that somebody has completely adjusted the front return to flat position sensor all the way to one end. Could it be this now, or something else?

 

[cuyamatow]

thanks!

Lee-online Nailed It!
I Have A 98 Cat 416C With The Same Bucket Curl Issue. Started With The Bucket Lift Function.. so I reversed The Up And Down Hyd. Hoses At The Lift Cylinders To Narrow The Problem..It Worked ,So I Left It Like That ..For 3 Years..(Everyone Who Jumped In My Backhoe Hated Me)..Then The Bucket Curl Started To Get Weak. And Soon The Bucket Lift(Formerly The Bucket Down Function) Got Weak So I Decided To Fix It.. The Repair Went Just As You Guys Described..Right Down ToAll Of The Detent Balls Falling Out..I Put Them Back And Packed Them W Grease , But They Must Have Fallen Out Cause I Lost Detent For The Float Option..I Never Used It But Im Worried About The Balls Floating Around In There..Any Tips On Getting The Balls To Stay In When I Put It Back Together?

 

[caterpillarmech]

Lots of cuss words seem to do the trick for me for getting the detent back on. I would pull all the resolvers and flush the valve bank. Just moving all the functions will clear the passages. Reseal and reinstall them. Should do the trick.

The detent is just a pita. You just have to fight it till you get it on. I always pack the sleeve with grease and install the balls. Keep a pan under it to catch them when they fall out.

 

[Demomann]

cat0420echls05092 I have a similar issue, it started intermittently then it sat for six months and now the front loader bucket won t curl at all. moving the stick to dump tugs at the engine try to curl and there is no change, backing up w/ the bucket down doesn't move it from full dump at all. could a seal on one of the resolvers cause this?