pto pump on L8000 dump

[monkey]

I think the hydraulic pump is going out on the dump bed, not real strong on the last extension, sometimes won't get all the way up.

95 L8000

had a guy helping me one day, he got out to take a **** or something, had left the bed up, engine running and control level in the up position. I smelled something funny and when I looked saw what appeared to be very hot (smoking) hydraulic fluid leaking out of the pump.

how hard is it to change the pump and where would I possibly look to purchase one??

Thanks

 

[Willis Bushogin]

its not hard at all to change the pump, four bolts, control/air cable and 2 hoses. just a PITB if you dont have a cutoff valve on the tank. Of course if the fluid got that hot, you might want to change all of it anyway. Make sure you install a ball valve on the bottom of the tank, if you dont have one.
do you have a shaft driven pump, or direct mount pump?
Where is it mounted? bottom or side?
You will need to know all this before you can get the correct one.
I would recommend buying a new/rebuilt one about $600, but the last one I bought I put a ad on my local Craigslist and got one for $200. I took a chance on it being a good one and it turned out OK
Lots of the big truck salvage shops has these, off of wrecked trucks
Im in NC and I could give you contacts in my area, but the freight would kill you
Good luck

 

[grandpa]

if its a direct mount to the tranny, your also gonna have to drain the transmission oil....

 

[mitch504]

Before I changed pump, I would get a guage and check the relief valve pressure. The heat could have softened the spring, or age could have. It's not unusual to have to tighten the valve a little a couple times in the life of pump.

 

[monkey]

thanks for quick replies

couple of questions..... I'm new to this whole used dump truck thing. I can work on my dozer or hoe with not to much problem, know where to get the parts also.

Thanks Willis for the possible assistance lol, I actually bought it out of NC

Okay, so where is the best place to go about procuring a new or reman. pump ? I go to Cat or Komatsu for my other equipment. Think my local Ford dealer would look at me funny

Mitch, ummm okay I really have no clue, where and how to check it. I don't pick up a Playboy for the articles....I kinda like pictures so i can see how things work :tong

It's up at the farm, I'll take a few pics

While I and if I get to the point of replacing it or fixing it......might need to look into taking care of this below
There is a ton of slop in the pivot pins on the cylinder...at least the bottom one that I can really see. Unless I'm on level ground and get it loaded pretty evenly, scares the bejesus out of me when the bed starts tilting one way or the other.....might this affect lifting performance also? Is there a normal type of procedure for tightening things up? The pin doesn't really look worn to much, the eye on the cylinder is what seems to be worn Can it be say, machined out and like a sleeve/bushing put in with a new pin. The pivot points at the back of the bed don't look to bad.

I'm just using this at my farm to dig out my pond.....not really looking to spend a lot of time working on it at this point. Just keep it dumping at this point already ran about 90 loads in her

again thanks for the replies guys

 

[mitch504]

If you post a pic of your pump, I should be able to tell you how in detail.

If the hinges on the back of the bed are good, I wouldn't wory about the cylinder pivots, unless they are worn to the point that they could break. All dump beds shift when they go up.

 

[mitch504]

Oh, and if the pump is bad, a local hydraulics shop may be able to repair it, and be the cheapest.

 

[Willis Bushogin]

most PTO's has a seal to prevent tranny oil from leaking out, when you change the pump

 

[mitch504]

most PTO's has a seal to prevent tranny oil from leaking out, when you change the pump

Yeah, Grandpa and I had a long chat about this, he always pulls the PTO and pump together, and puts bearings in the PTO, when he changes a pump.

 

[monkey]

well I'm gonna go up Thurs. I'll snap a few pictures and you guys can better point me in the right direction

My preference would be to have a new or reman. pump, just go up pull the old one off and put the new one on and get back to work....minimal down time

Or haul the truck (the truck nor I (no cdl) is road legal) back to my house (80 miles) and see about getting the pump rebuilt and maybe seeing about getting the pivot areas fixed.....lol, I realize beds tilt some, I think mine tilts to much maybe take care of a few other little things

But I would rather just keep working for awhile till it gets cold out in about 6 months:tong

 

[willie59]

When dumping loads, it's preferable to keep bed horizontal to direction load is being dumped. Dumping on side slopes puts a lot of stress on cylinder rod. Sometimes it's unavoidable to dump on side slope, but one should use caution doing so.

 

[monkey]

here's the pump
there is a ball valve under the tank

 

[monkey]

kinda hard to see, eye balling looks to be about 3/8ths of inch of slop. That's the bottom pivot

 

[monkey]

When dumping loads, it's preferable to keep bed horizontal to direction load is being dumped. Dumping on side slopes puts a lot of stress on cylinder rod. Sometimes it's unavoidable to dump on side slope, but one should use caution doing so.

trust me, it tilts bad enough on flat ground if I don't evenly load it, I avoid slopes all together

 

[jkflatt]

Watching this thread as I may have a similar problem. Cylinder extends properly but don't lower. Checked linkage and seems OK. There is a cable on the back of the pump that goes to the rear of the bed that looks loose if it's suppose to reset or open the valve? Any advise appreciated as I'm new to dumps.

1995 Ford F800 w/ Ledwell dump bed. Allison auto tranny.

 

[Willis Bushogin]

The biggest problem you have when the bed is slow to lower, is the linkage adjustment. Look at the shinny rod/piston that you see coming out of the pump, Is there a little shinny rod showing (like its not going back to down position, it will be slow) I just bought another truck and had to adjust the linkage and replace the bolts in the pump lever. Im referring to a pump with a manual cable, air shift is a little different and they dont, give as much problems as cable controlled units.
The cable that you are referring to, pulls the PTO out of gear, just before it reaches the top.
If this problem just started, its probably the linkage adjustment
If its been like this since you have had the truck, it could be linkage, or the hose on the cylinder is too small. Does it go up slow (do you really have to give it the gas, to go up?) Is the valve closed a little

Very brief thing on the hinges, its really hard to see what you have, but if the shaft is worn real real bad, its kinda simple to replace it, if its the hinge flange itself, weld the shaft to the outer hinge points, this will leave the center/bed hinge points to work. Or you can weld the inside bed hinge and leave the outside to turn. You really dont want to get into replacing that whole thing/bracket. Make sure you have the bed don and flat, so everything is kinda normal position. I have had these items worn so bad I could put a larger pin in, with a little trimming
Good Luck

 

[grandpa]

That cable that runs to the back needs to be adjusted so that just b4 the cylinder reaches the end, the cable tighten's and pull the spool control on the pump to neutral.

As far as the cylinder not going down when the down lever is pushed would be that same spool probably not going forward enough when you move the lever to the down postion.. If in fact the proper adjustment is moving the spool forward all the way then the problem exist's in a hose or a blockage coming back. (I have seen the rubber come lose on the inside of a hose allowing the oil to flow one way but not back) Good luck... Gramps

LOL After i posted this I then saw willis post... carry on.

 

[monkey]

well my problem, lol, I do think the pump is going bad

Getting weak, to big a load and it will only go up about 3/4's of the way, even a half way decent load and it struggles at the top, really have to mash the throttle to keep it going

I would like to just replace it. so my question is....where do i get one and what do I ask for????
looking at the picture, is it just a pretty straight forward swap? Somebody mention draining the tranny?

Thanks guys

 

[mitch504]

It is a straight forward swap. You just remove the hoses and control cable, then the 4 bolts set in about a 6" square vertical flange about a foot forward of the rear of the pump.

Granpa was talking about removing the PTO and rebuilding it at the same time, when he mentioned draining the transmission.

I would still check the relief valve before buying a $600 pump. To do this, disconnect the hose going to the cylinder,get a 5000 psi gauge and dead-end the hose into it. Put the control valve in the raise position,have someone rev the engine, and see if the pressure reaches 2500 psi.

The relief valve is the threaded stud with the screwdriver slot in it below the suction hose with the hose clamps on it. To raise the pressure, you loosen the locknut and turn in the stud with a screwdriver.

Good Luck,
Mitch

 

[monkey]

thanks alot Mitch, I'll give that a shot