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.

 

[J_J]

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??

View attachment 418012
View attachment 418013

If your BH is the last valve in the hyd system, it really does not need a relief valve.

One relief valve per system will work.

You could use a no relief valve, which is a special plug.

If your broken relief spring was letting the relief valve dump at say 1000 psi, then you would be losing a lot of BH power.

 

[parluskq]

This relief valve is located on the FEL spool, and as far as i can tell it is the only relief valve in the system. I looked on the BH spool and there are only plugs where the relief valve should go, but this is good knowledge to know. If for some reason i am unable to locate the spring I may be able to delete the FEL relief valve and just install one on the BH spool.

 

[J_J]

The first valve after the pump should have the relief.

You could also add external relief valves inline in front of any valve.

 

[Leejohn]

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

Thank b7610hsd he was the one that posted the link.

 

[parluskq]

thanks b7610hsd you are a lifesaver, I found my exact valve on page 15. I couldn't get a hold of the guy from parker that deals with the gresen line. I will try again tomorrow. I busted a hydraulic hose today so I will have to replace it before I go further!

 

[b7610hsd]

I just did a Google search for a Gresen 2702 spool and it led me to the Sp 2 valve pdf.

 

[parluskq]

Well i finally got a call back on the springs.... Parker has them in stock and the distributor in my state is able to get them. but I have to order at least two and they are $70 each!!!!

 

[J_J]

$70 for a relief spring. What a bunch of crap.

I would just add a BB or small ball bearing to make up the difference.

or

Just do away with the relief valve and plug wiht a no relief valve and the add an external relief valve.

1/2 NPT 16 GPM 1000-2500 PSI RELIEF VALVE

 

[parluskq]

yeah not to mention that i would have to buy two. I did find something on ebay that may work. (picture Below) I called parker and there were unable find the part pictured. they said 2818 didn't come up in their system. the relief valve looks the same and it is marked HP on the side which i assume means high pressure. the only issue is that there are three different types of valves sp spk and ssk. the spk and ssk use the same relief valve but the sp is different. I to me it is a 50-50 shot in the dark.