Hunter RL Alignment Lift unbalanced when going up or down

[pelletman]

I am trying to figure out a problem with an older Hunter RL 7000# alignment lift. Going up one side sags. Going down it is the same, the right side appears to be the problem. I have the manual, I have disassembled the 4 way valve and the 2 way valves and they all appear to be in good condition from a visual inspection, cleaned with brake cleaner, blown out with compressed air and reassembled and it didn't seem to make a difference. If I leave the two way valves closed (I think-in the normal position) the lift will try to lower but only go down a bit before the locks reengage and it stops. In order to get it to go down I have to open one of the two way valves AND open the 4 way valve. Anyone have any experience with these lifts? Appreciate whatever info you may have. Thanks!

 

[39CAMC]

How far out of balance is it? When I had one of those, it would get about 1-1.5 out and when I asked my Hunter guy about it, he said "Those RL were always funky " End of conversation....

I got in the habit of running it all the way up first to level it, or setting it on the alignment legs (which since I was mostly doing alignments, was not a big deal.
Mine was just out enough to look funny but never bad enough to dig further into it. I played with the valves like you and couldn't figure anything out. I debated looseing the giant bolts on the cross beam but never did.

DaveW

 

[pelletman]

How far out of balance is it? When I had one of those, it would get about 1-1.5 out and when I asked my Hunter guy about it, he said "Those RL were always funky " End of conversation....

I got in the habit of running it all the way up first to level it, or setting it on the alignment legs (which since I was mostly doing alignments, was not a big deal.
Mine was just out enough to look funny but never bad enough to dig further into it. I played with the valves like you and couldn't figure anything out. I debated looseing the giant bolts on the cross beam but never did.

DaveW

Way too much, it gets scary. There is obviously an issue, I don't think it is binding, seems like uneven pressure going up and down. I have to open a couple of the valves (one two way and the 4 way) to get it to go down presently

 

[39CAMC]

What happens if you switch the hoses left to right? Am I thinking correctly that if it were a hydraulic issue, that would make the other side go up too fast?
Just vomiting ideas....

DaveW

 

[pelletman]

What happens if you switch the hoses left to right? Am I thinking correctly that if it were a hydraulic issue, that would make the other side go up too fast?
Just vomiting ideas....

DaveW

I have thought of this, and I have not done it yet. I am pretty sure it will cause the problem to happen on the other side. Seems like a valve is partially open when it is going up, and partially open when it goes down. I suppose a hose could be collapsed and causing the problem though. I think I will swap the hoses next

 

[pelletman]

OK I am back at this lift issue. I put a gauge on the aluminum distribution block for lack of a better term, and it reads 2500 psi as it should. Coming out of the block they never go over 1000 and then one falls to zero as it is going up. I am changing the fluid and have more coming tomorrow, (5 gal capacity of Dextron II) so testing is done for the day. Anyone ever have this block apart? I am hoping I find something obvious.

 

[pelletman]

The solenoid valve on the right came apart, and I have no idea how. Pretty sure this is the problem. If you look at the pictures of the valves they both should look the same. For some reason the one on the right came out without the bottom half. I lost a couple of the small parts that are in the valve when I took it to my ultrasonic cleaner somehow so I am buying another valve. Valve is SV80-MS and both are exactly the same. You can see part of the valve in the body, it came right out with a dental pick

 

[pelletman]

This is the valve for both

Hydraforce SV08-20MS - Electrical Component - Solenoid

Elevate your heavy machinery's capability with our industrial-grade Solenoids.Specially designed for heavy equipment, these solenoids ensure high reliability in activating hydraulic valves, starters, and other critical components. They are built to withstand the rigors of heavy-duty use.Key...

aztechydraulics.com

 

[pelletman]

OK, that valve is just a bit longer than the original, but it works fine, other than you can't put the sheet metal back on unless you cut a hole in it or pad it out somehow. Leaving all this info here for the next guy with this problem. Had I realized initially that the valve on the right had come apart, I could have saved lots of time and effort.

 

[pelletman]

Here are the manual and parts diagram in case anyone needs them

 

[pelletman]

I had to rebuild the jack unit in the rolling jack. Here is the manual which is pretty close but not exact. I basically had to clean mine out as the rubber bumper had disintegrated and it was full of ****