[frank.koetter]

I have a new to me 2000' 4000 Express.  My garage hatch is starting to move slowly.  When I took a look at the hydraulics it looks like the filter hasn't been replaced in a long time.  My question has anyone changed the hydraulic fluid?

What type of hydraulic fluid, where does it drain, how much fluid?  Any other hints that would help me go at this.  Thanks in advance!

[MC1600]

I asked this question when I bought mine a little over a year ago, and here’s the process I got back:

1. To do this, all hydraulics have to be closed, but you have to be under the laz to do it. So, open the laz, prop the door open, unclip the hydraulic cylinders, and close them.
2. Drain the hydraulic fluid from under the white pump in the trunk.
3. Remove and replace the filter.
4. Refill the pump, actuate everything a few times, and refill as necessary.

The manual says it’s a “self-bleeding system,” so that *should* be it. I didn’t end-up doing this as I got distracted with other things last year, but it’s on my list for this spring.

[frank.koetter]

I asked this question when I bought mine a little over a year ago, and here’s the process I got back:

1. To do this, all hydraulics have to be closed, but you have to be under the laz to do it. So, open the laz, prop the door open, unclip the hydraulic cylinders, and close them.
2. Drain the hydraulic fluid from under the white pump in the trunk.
3. Remove and replace the filter.
4. Refill the pump, actuate everything a few times, and refill as necessary.

The manual says it’s a “self-bleeding system,” so that *should* be it. I didn’t end-up doing this as I got distracted with other things last year, but it’s on my list for this spring.

Thanks, so much for the reply.  Much appreciated.

[Faeske1904]

Hello, I have only 1 working table now, rest does not work ( engine hatch, back hatch and 1 table) I think the directional valves need to be changed because of corrosion. Does anyone know if you can do it yourself and where can I buy them? Was looking on the internet with the numbers of a previous post on the forum but do not find it. I am from Spain, Malaga. Thanks

[frank.koetter]

I asked this question when I bought mine a little over a year ago, and here’s the process I got back:

1. To do this, all hydraulics have to be closed, but you have to be under the laz to do it. So, open the laz, prop the door open, unclip the hydraulic cylinders, and close them.
2. Drain the hydraulic fluid from under the white pump in the trunk.
3. Remove and replace the filter.
4. Refill the pump, actuate everything a few times, and refill as necessary.

The manual says it’s a “self-bleeding system,” so that *should* be it. I didn’t end-up doing this as I got distracted with other things last year, but it’s on my list for this spring.

I got distracted as well.  But now I'm at the point I have to do something.  The information regarding all hydraulics having to be closed is very helpful. 

Assuming I can find the pump drain plug, and drain the hydraulic fluid.  Does anyone know the preferred fluid AND how much fluid is needed to re-fill?

[Alan615]

I'm about to service this system in my 4000 express, year 2000. A decal on the DYNA JACK unit indicates " Use Dextron automatic transmission fluid only. The use of other fluids may cause the unit to fail. Fill the tank to within 1/2" from the top with cylinders collapsed".

The reservoir tank is about 490 cubic inches which equities to about 8.5 quarts of ATF. The current filter is a Zinga BE-10-18 (10 micron), I'll be using a Donaldson P550426.