Power steering???

[JD-thomas]

I got a 450A track loader.. It turns fine to the right, but it only attempts to turn to the left when you pull back it just attempts to jerk then nothing, looking thru the inspection hole clutches appear to be equall in wear. Tried using manual to adjust with no luck... Was wondering if it is possible to have a bad power steering cylinder. If it is not sending the same pressure to the left clutch as the right would that cause this issue.... Just shooting into the dark. I need it fixed, Any thoughts or input would be great. The left cylinder has more play in it than the other....

[tjdub]

I doubt it is anything to do with the power steering. Those cylinders are just "power assist" and don't affect the steering other than making the levers easier to pull. Just watch the linkage on the back of them when you pull both levers. If the linkages appear to move equal amounts for both levers, the issue is internal.

When you say it just jerks a little, do you mean the left track doesn't stop moving at all, but you feel the engine grunt? Was the machine steering fine when parked last? It's pretty common for the clutches to rust up when sitting for a long time.

[JD-thomas]

One cylinder seems looses than the other and is no where as tight as the other. Yes when I pull the lever the track stops driving, but the right one doesnt keep going to turn the machine. It sounds like a whine I stood up on it while driving, with inspection covers off looking down at clutch packs. The right side does fine, but the left when you pull the lever, it's like the brake band doesnt lock tight enough, but if you tighten it up it makes it jerk worse... It acts like there might be a pressure lose in spool valve that operates the clutch pack....

[JD-thomas]

I bought the machine 1 1/2 years ago it had been parked for a couple years. I had to replace the motor in it. The guy I bought it from said it was fine when last ran. And it was okay when I first started using it just has progressively gotten worse.....

[mikeintn]

Sounds like the right clutch is slipping, if adjusted right then proberly something bad inside, pressure plate or maybe clutches just woren out

[Jack-the-Ripper]

On the 450A the connection from the steering lever to the clutch/brake is completely mechanical. The input and output shafts of the steering cylinders are the same piece of metal. When the 450A sits awhile the pivots of the linkages inside the clutch housings can get rusted. When you activate the clutch/brake lever it first pushes against a throwout bearing on the clutch pack to deactivate it, (then activates the brake) through a bunch of linkages. Two things have to happen to turn left - the left brake has to engage and the right track has to drive. The machine will drive forward if only the left track drives but will not turn left when the right track doesn't pull. Most likely at some point when you pulled the right lever the linkages had too much friction to allow the return springs (assuming they are not broken) to reengage the clutch so now the right track is not getting full power. If this is the case, you will have to remove the clutch pack on the right side, disassemble, clean and lubricate the linkages. You can see the top of the throw out rods through the access holes. They have a short arm through which passes the clutch adjusting bolt. When you activate the steering levers you should see both of these travel through the same range of motion.

[tjdub]

when I pull the lever the track stops driving, but the right one doesnt keep going to turn the machine. It sounds like a whine I stood up on it while driving, with inspection covers off looking down at clutch packs. The right side does fine, but the left when you pull the lever, it's like the brake band doesnt lock tight enough, but if you tighten it up it makes it jerk worse... It acts like there might be a pressure lose in spool valve that operates the clutch pack....

Like Jack said, it's all mechanical inside, there's no hydraulics operating the clutch plate. That whine you hear is the right side steering clutch slipping under load. It will do the same thing if you're not pulling any lever and are trying to push on something. Either the clutch is partially engaged due to the clutch linkage being adjusted too tight, or the clutch is broken, worn-out, or oil-soaked.

I would go through the full adjustment procedure again. Loosen brake and clutch on the linkages, tighten brakes from the side, get lever freeplay right, tighten linkages, loosen brakes from the side. If you do all of this and can see the clutch and brake are activating properly through the inspection plates and it still slips, then you'll have to pull the right side steering clutch.

Also, have you taken out the drain plugs out of the bottom of the clutch housings to see if they're full of oil/water?

[JD-thomas]

Well the plugs were out of the housings already so they are dry, the service manual for the machine says they are supposed to be wet clutches, however I contacted the owner of the machine before me. He owned the machine for 22 years so I figured he'd know. He said he never ran fluid in the clutches, and he had some issues with the linkages and periodically he would open up the housing and blow out the fine dust in the housing he said it would let the cluthes slip. Now let me make sure everyone understands that this is one of the foreign French built machines.... Thanks for any help I plan on messing with it this weekend so I would like to get a plan together.