Leaking 7308 loader valve

[billfires]

Using my 1920's backhoe when I noticed fluid leaking from the control valve while I was operating the BH. The leak stopped when I wasn't running the BH. I was briefly able to inspect it but can only determine it is not leaking from any of the connections. Before I remove the valve I was wondering if anyone has had any type of a similar problem. Thanks for any help, Bill C

 

[jinman]

Bill, it's been several days since you posted, and your post is a bit confusing to me. Your title to the thread says a leaking 7308 loader valve (dual-port joystick valve?). However, you describe using the backhoe. Am I understanding correctly that your loader's joystick valve leaks when your backhoe valves are operated? If that's true, then your joystick valve is just leaking anytime the system is under pressure. With no work being done with the hydraulics, the open center valves allow a high quantity of fluid to pass at low pressure. As soon as any valve is operated to do work (i.e. the backhoe) then the whole system becomes pressurized. If that's when your FEL joystick valve leaks, it should also leak some when the FEL is used or there's a heavy load on the 3PH. Of course, if you have a subframe BH installed, you probably don't use the 3PH lift arms. Can you clarify if the BH is causing the FEL joystick valve to leak?

 

[billfires]

Jim, you are correct in that it doesn't leak with out pressure being used. It is a dual-port joystick. I took the sheet metal cover off the valve and ran the BH through it's range but can not identify exactly where the leak is coming from. I was hoping someone had a similar problem but with no other responses I'm thinking I will have to disconnect the hoses from the valve body and unbolt it. I could not find the loaser valve on the NH parts diagram. I will probably take it out and cover the lines with plastic bags. Thanks for your help, Bill C

 

[jinman]

Bill, I'm not sure how you've been searching, but the Messick's site shows a Prince 2-spool remote valve for the 7308. It's the last 2-spool valve in a list of several. It's reference number under "Hydraulic Systems" is 05I01b. The exploded diagram is shown below. Oh yes, it's under the 1920, not the 7308 loader.

 

[billfires]

Jim, thanks for the drawing. I was looking under the NH site and could not locate it under either 7308 or 1920. It looks like there might be a rebuild kit in the diagram. I will have to look it up on messicks.com. Thanks again, Bill

 

[billfires]

An update. The valve also leaks when utilizing the loader too. After removing the sheet metal top cover, hyd. fluid was spraying sideways from the valve. I undid the loader quick connects and the realized to remove the valve that all the metal hyd. lines under the valve have to be removed. I was successful in getting 2 of them removed late yesterday afternoon. Will attempt to finish the rest Wed. I will take photos as I go along. Bill C

 

[J_J]

He must be talking about a dual joystick BH valve.

How many spools/levers are on your BH valve

He is also talking about removing hoses from the loader valve.

The BH valve is probably a stacked valve and the seals between the stacks are leaking.

Maybe a fitting also.

Could be a pin hole in one of the hose.

It should be obvious when you load up all the valves when raising the 3pt up to max. The relief will activate, and high pressure will be in all the open center galleries from pump to the 3pt cyl..

Show pictures of both valves and describe where you think it is leaking.

 

[billfires]

JJ and Jim, I reread my post and realized I did not specify that the leak is coming from the 2 spool Prince loader valve. I have removed all the metal lines that go to the loader quick connects. I just sprayed PB Blaster on the other, longer metal lines that go underneath. One thing that I should have done is to remove the loader first, would have made access much easier. I was surprised that the fittings are SAE. Bill

 

[billfires]

An update, took the Prince valve off the tractor and took it to a trusted equipment repair shop that referred me to a hydraulic repair shop. Dropped the valve off and got a call the next day that it was all set. When I picked it up he had replaced the corroded side plug. He said they removed the fitting on top of the valve (to see into the valve) and tried to remove what was left of the plug with an Allen wrench but there wasn't enough material left. It came out with an easy out. He had a little difficulty locating the replacement plug but eventually located one locally. The cost was $45.00 and the turnaround was less than 23 hours. I hope to reinstall it on Sun. I asked if he thought I should replace it on a regular basis and he said it should not happen again. I will post pictures when I figure out how to get them off my phone. Bill C

 

[jinman]

Wow! Great turnaround and a great price. Is that your newest favorite shop?