Whittaker Two Port: Dump Rebuild

strong>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 Monster Green square you will see that the valve will eventually need new seals. Take extreme care in servicing one of these valves as they are not easily replaced.

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

Remember where you saw it first!

We begin by cutting the lock wires to the solenoid and bottom plate of the dump.

We begin by cutting the lock wires to the solenoid and bottom plate of the dump.

Before we unscrew the solenoid from the body oil is put in the hole on the valve body that is showing the threads of the solenoid. The valve is then put in a vise with a towel to protect the valve.

Before we unscrew the solenoid from the body oil is put in the hole on the valve body that is showing the threads of the solenoid. The valve is then put in a vise with a towel to protect the valve.

 Whittaker Two Port: Dump Rebuild

The solenoid is now coming out of the valve body.

 Whittaker Two Port: Dump Rebuild

With the solenoid off the valve body the plunger and spring is exposed.

A look at the solenoid from the bottom.

A look at the solenoid from the bottom.

Whittaker solenoid.

Here is the solenoid.

 Whittaker Two Port: Dump Rebuild

The valve is just about ready to come apart.

Remove the bottom plate by taking out four screws.

Remove the bottom plate by taking out four screws.

Now time to take the plunger out. Locate the set screw on the side of the plunger.

Now time to take the plunger out. Locate the set screw on the side of the plunger.

After undoing the set screw the plunger will turn right off the shaft.

After undoing the set screw the plunger will turn right off the shaft.

Here is the valve with the plunger removed.

Here is the valve with the plunger removed.

Push your thumb in on the shaft.

Push your thumb in on the shaft.

Watch the bottom of the valves as you push on the shaft.

Watch the bottom of the valves as you push on the shaft.

The shaft and spool will begin to come out of the valve.

The shaft and spool will begin to come out of the valve.

 Whittaker Two Port: Dump Rebuild

Two spring loaded bushings help seal the spool.

 Whittaker Two Port: Dump Rebuild

The valve is just about all apart.

Parts inside the Whittaker valve.

Parts inside the Whittaker valve.

Detail of bottom plate.

Detail of bottom plate.

Whittaker Spool up close.

Spool up close.

Close up of plunger and spring.

Close up of plunger and spring.

The solenoid.

The solenoid.

The side ports are removed from the valve body. THIS IS THE ONLY WAY TO GET THE SPOOL BACK IN THE VALVE BODY! Take the bushings out of the side ports along with the small springs. Clean and oil these parts. Replace the seals on the port threads.

The side ports are removed from the valve body. THIS IS THE ONLY WAY TO GET THE SPOOL BACK IN THE VALVE BODY! Take the bushings out of the side ports along with the small springs. Clean and oil these parts. Replace the seals on the port threads.

The spring is put back in the side port.

The spring is put back in the side port.

The bushing is put back in place.

The bushing is put back in place.

At this point the valve body is cleaned. You will notice several small O-rings in the shaft chamber of the valve body. Use a tooth pick to remove the O-rings and replace them.

At this point the valve body is cleaned. You will notice several small O-rings in the shaft chamber of the valve body. Use a tooth pick to remove the O-rings and replace them.

With the spool in place you can put the side ports back on the valve body. The valve can then be put back together.

With the spool in place you can put the side ports back on the valve body. The valve can then be put back together.

How To Convert Normally Open To Normally Closed Valves

Every now and then you will stumble across a valve that is set up for normally open use. The Whittaker valves can be converted over to the normally closed type used on lowriders. The spool can be turned either way to operate how you wish.

A Whittaker valve you may think is useless as a normally open valve can be converted by just turning the spool the other way inside the valve body.

A Whittaker valve you may think is useless as a normally open valve can be converted by just turning the spool the other way inside the valve body.

This valve is setup as normally open. Notice the hole is closed in the energized position.

This valve is setup as normally open. Notice the hole is closed in the energized position.

This valve is setup as normally closed. Notice the hole is open in the energized position.

This valve is setup as normally closed. Notice the hole is open in the energized position.