Generic Square: Dump Rebuild

Attention: Welcome to our new aircraft hydraulics section! We hope you find this section we have put together informative and interesting. You may notice that some part numbers and so forth are blurred out. One reason we didn’t want to post full part numbers because it has taken us months of searches to get the information we have. It wouldn’t be fair to us to just give up our hard work and research. Not too many people know about this stuff and the ones that do don’t want to talk about it. We feel this is just the right amount of info so we don’t upset anyone on either side. The biggest reason for not giving out full part numbers is because we don’t need every lowrider to call up aircraft surplus places looking for things. Most warehouses don’t want to sell to lowriders and the ones that do are raising their prices beyond a reasonable amount because people are willing to pay to much for stuff the warehouse considers junk. Lets keep prices down and think about it before you offer a insane amount for a used pump that needs a rebuild. If you are going to track parts down don’t say that it is for a lowrider. Know what the full part number is, what aircraft it goes in, the proper name for the part and the function of that part. Take the time to research the surplus industry and know the lingo they use. Remember not to use lowrider lingo when talking with them because odds are they have a different term for the part you are looking for. With a little research and some luck you’ll be able to find what you need.

Warning: If you are unsure about doing anything do not attempt the take apart the dump. Internal parts like the spool and sleeve must be flawless and not scratched. Remember the old saying ” if it isn’t broken don’t fix it. ”

When you own a dump like a generic square you will see that the valve will eventually need new seals.

In this section we will tear down a generic square dump valve, inspect / replace seals if necessary and check the spool and sleeve. Lets take a look at how Jay rebuilds these dumps.

Remember where you saw it first!

This job required special tools. A brass sleeve / spool extractor, brass O-ring removal tool, set of punches, toothbrush and O-ring lube all help make the job easy.

This job required special tools. A brass sleeve / spool extractor, brass O-ring removal tool, set of punches, toothbrush and O-ring lube all help make the job easy.

Generic Square Rebuild

These valves are still out there. If you have one we will show you how to service it.

Generic Square Rebuild

Notice the top connector on a generic square has a blue insert.

Adel" valves with the 1996Hor 1994H serial numbers, they are fake.

Notice the serial number on this valve is 1996H. Valves that say Adel on them with this serial number are mass produced fakes.

Remove the four screws at the candle and remove the solenoid.

Remove the four screws at the candle and remove the solenoid.

Generic Square dump Rebuild

Notice the pin that must be removed from the plunger.

Carefully remove the pin from the plunger using a small nail and hammer. Gently tap out the pin.

Carefully remove the pin from the plunger using a small nail and hammer. Gently tap out the pin.

Here is the top of the valve with the plunger removed.

Here is the top of the valve with the plunger removed.

Generic Square dump Rebuild

Remove the four screws for the bottom plate. Twist the bottom plate until one of the corners is near the side to make removal easy by hand. NEVER pry off the bottom plate with any tools.

Remove the bottom plate, retainer and O-ring. Then remove the shaft.

Remove the bottom plate, retainer and O-ring. Then remove the shaft.

Back to the top of the valve body.

Back to the top of the valve body.

 Remove the retainer by hand and remove the O-ring.

Remove the retainer by hand and remove the O-ring.

The spool is carefully removed using a brass rod 1/16" thick by inserting it into the small hole in the top of the valve body. Gently guide the spool out of the bottom of the valve. USE EXTREME CARE IN REMOVING THE SPOOL. NEVER INSERT ANYTHING ELSE OTHER THAN THE BRASS ROD IN THE VALVE BODY.

The spool is carefully removed using a brass rod 1/16″ thick by inserting it into the small hole in the top of the valve body. Gently guide the spool out of the bottom of the valve. USE EXTREME CARE IN REMOVING THE SPOOL. NEVER INSERT ANYTHING ELSE OTHER THAN THE BRASS ROD IN THE VALVE BODY.

The spool is removed from the valve body.

The spool is removed from the valve body.

The 1/16" thick brass rod is inserted again into the top of the valve body. You want to touch to very top of the sleeve and flip the valve body over with the brass rod resting on the bench gently push the the valve body down until the sleeve begins to come out of the body. Once the sleeve is half out you can pull it out by hand. USE EXTREME CARE IN REMOVING THE SLEEVE. NEVER INSERT ANYTHING ELSE OTHER THAN THE BRASS ROD IN THE VALVE BODY.

The 1/16″ thick brass rod is inserted again into the top of the valve body. You want to touch to very top of the sleeve and flip the valve body over with the brass rod resting on the bench gently push the the valve body down until the sleeve begins to come out of the body. Once the sleeve is half out you can pull it out by hand. USE EXTREME CARE IN REMOVING THE SLEEVE. NEVER INSERT ANYTHING ELSE OTHER THAN THE BRASS ROD IN THE VALVE BODY.

The sleeve is removed.

The sleeve is removed.

Use your pinkie finger to remove the O-ring, Teflon back up and aluminum retainer. Also remove the spring.

Use your pinkie finger to remove the O-ring, Teflon back up and aluminum retainer. Also remove the spring.

The valve apart.

The valve apart.

Generic Square Rebuild

The sleeve.

The spool. Generic Square Rebuild

The spool.

The spool soaks in a cup of our special light oil blend for valves.

The spool soaks in a cup of our special light oil blend for valves.

The sleeve soaks in a cup of our special light oil blend for valves. Notice the O-rings have been removed. REMEMBER TO NEVER PRY THE O-RINGS OFF THE SLEEVE WITH ANY METAL TOOLS. BUY A SPECIAL PLASTIC O-RING REMOVAL TOOL.

The sleeve soaks in a cup of our special light oil blend for valves. Notice the O-rings have been removed. REMEMBER TO NEVER PRY THE O-RINGS OFF THE SLEEVE WITH ANY METAL TOOLS. BUY A SPECIAL PLASTIC O-RING REMOVAL TOOL.

 New O-rings are reinstalled on the sleeve. The spool is carefully reinserted into the sleeve using some light oil blend. The valve spring is put on top of the assembly and all the O-rings are coated in a light coat of either Parker Lube, Vaseline, or bearing grease.

New O-rings are reinstalled on the sleeve. The spool is carefully reinserted into the sleeve using some light oil blend. The valve spring is put on top of the assembly and all the O-rings are coated in a light coat of either Parker Lube, Vaseline, or bearing grease.

Inside the the valve body is coated in a light coat of either Parker Lube, Vaseline, or bearing grease. The body is slowly pushed downwards onto the spool / sleeve assembly.

Inside the the valve body is coated in a light coat of either Parker Lube, Vaseline, or bearing grease. The body is slowly pushed downwards onto the spool / sleeve assembly.

The sleeve can then be pushed in further using your two thumbs. Now follow the steps backwards prior to the removing the spool step. Don't forget to replace the bottom plate O-ring and the two shaft O-rings. Make sure you lube those O-rings as you did with the sleeve.

The sleeve can then be pushed in further using your two thumbs. Now follow the steps backwards prior to the removing the spool step. Don’t forget to replace the bottom plate O-ring and the two shaft O-rings. Make sure you lube those O-rings as you did with the sleeve.

This valve was tested in Jay's car to make sure everything was moving freely.

This valve was tested in Jay’s car to make sure everything was moving freely.

The valve is finished and ready to go back to it's owner.

The valve is finished and ready to go back to it’s owner.