Need Help! on Gresen control valve

[parluskq]

I have a older 75 terramite and am working on the hydraulics. My front end loader is strong but the backhoe is weak. I decided to check my pressure relief valve and found that the spring is broken(picture below) . I have searched the internet for days trying to find a replacement spring with no luck. The only info i can find on the control valve is that its a gresen 2702 (picture below). I tried calling parker and that couldn't help me without a part number. 2702 means nothing to them. Does anyone know what model this valve is? or where i can find a replacement spring??

 

[parluskq]

The is the only spring that i have found that may be close... HIGH PRESSURE RELIEF VALVE SPRING FOR 9-1790

 

[J_J]

Can you not grind off the defect and screw the nut down to increase the pressure.

Maybe you can use a relief spring from a similar valve.

Do you know what the relief pressure is supposed to be.

 

[Leejohn]

If the wire size and O.D. of the spring are same as yours, I would get it and cut that one down. If you grind the old one flat there would be a chance the relief valve not open all the way, because the travel would be short. If that happens psi could keep building and blow hoses.

 

[b7610hsd]

I found this info on a Sp valve which references spool #2702 on page 9. Maybe help. http://www.parker.com/literature/Hy...ce Literature/Bul HY14-2715-M1 SP SPK SSK.pdf

 

[Leejohn]

That should get him the spring, good info there.

 

[parluskq]

I first tried to weld the spring back together, didn't hold up. Then i tried to grind the bigger part down flat and screw the pressure stem in but there wasn't enough adjustment. I am not sure what the pressure is supposed to be on this backhoe. When i was testing it out yesterday I found something that confused me even more. if i leave the front bucket off the ground the backhoe has enough power to pick the rear end of the machine off the ground, but if i put the front bucket on the ground and lift the front wheels it doesn't. not sure if that has to do with physics or hydraulics

 

[Leejohn]

Did you look at that link?

 

[parluskq]

Leejohn, you are awesome... the relief valve is actually listed on page 15!!!!!

 

[parluskq]

Thanks again for the help, everyone. The part number for the spring is 1212-001 as soon as the people from parker gets back from lunch I am going to see if it is still available. I am hoping that will fix a lot of my problems.