HST Oil Change: Fact or Fiction?

[rswyan]

Mine were never changed religiously.

But, they did get the pan dropped, or drained, and 4 quarts of fresh fluid put in on occasion.

My new van, doesn't have a transmission dipstick, and insists no service before 100,000 miles!?

My van didn't come with a dipstick either - it's considered a service tool, available from Dodge/Freightliner/Mercedes.

The transmission has two Hall Effect sensors (magnets) on a plastic circuit plate to calculate the speed of the input shaft. The magnets on these sensors are prone to picking up ferrous wear metal that can cause the transmission to malfunction, throw codes, and go into "limp-home mode".

In order to clean them off you have to drop the pan and the valve body.

Before this issue was identified, dealers were replacing quite transmissions as "failed" when they probably weren't.

 

[ovrszd]

Does anyone worry about cross over contamination with the implements that share the same fluid, grapples, backhoes, etc . . . ., anything with a hydraulic cylinder, - that fluid will be going through your transmission with HST.

Yes. I mentioned that earlier as a contamination issue. As well as dirty quick couplers.

Countrybumpkin mentioned using starting fluid for a cleaner which I thought was a great idea!!!

 

[ray66v]

Before this issue was identified, dealers were replacing quite transmissions as "failed" when they probably weren't.

Reminds me of my $350 furnace blower motor, that failed early.

The first one was warranty.

When it happened the second time, on my dime, I looked at the circuit board attached to the motor, and found a burnt part.

After doing some research, I discovered this part, a thermister, fails on these all the time, and is not serviced.

They just sell you a new motor, for $350 plus labor.

I found the thermister online, at an electronic supply store, for $3.50.

I keep them in stock now.

 

[Ivan49]

Yes. I mentioned that earlier as a contamination issue. As well as dirty quick couplers.

Countrybumpkin mentioned using starting fluid for a cleaner which I thought was a great idea!!!

When my new tractor was delivered the guy that delivered it was the service manager I asked about my othe things that the hyd hooked up to and he said just hook up and go. I stll have not done this because I am afraid of mixing new fluid with old. I have a couple of thing with 4 inch dia cylinders 24 inch stroke and they hold a lot of oil. I think I am going to take the lines off and drain them and lines also then hook up to the tractor. Anyone have any other ideas? I like the idea about using starting fluid also

 

[IslandTractor]

When my new tractor was delivered the guy that delivered it was the service manager I asked about my othe things that the hyd hooked up to and he said just hook up and go. I stll have not done this because I am afraid of mixing new fluid with old. I have a couple of thing with 4 inch dia cylinders 24 inch stroke and they hold a lot of oil. I think I am going to take the lines off and drain them and lines also then hook up to the tractor. Anyone have any other ideas? I like the idea about using starting fluid also

Virtually nobody does that. No harm but certainly will take some time and create a bit of a mess.

Do you also steam clean the interior of your car engine each time you change the oil? There will always be a little "cross contamination" but that is what filters are for.

 

[ovrszd]

When my new tractor was delivered the guy that delivered it was the service manager I asked about my othe things that the hyd hooked up to and he said just hook up and go. I stll have not done this because I am afraid of mixing new fluid with old. I have a couple of thing with 4 inch dia cylinders 24 inch stroke and they hold a lot of oil. I think I am going to take the lines off and drain them and lines also then hook up to the tractor. Anyone have any other ideas? I like the idea about using starting fluid also

To get a good dump you'll have to remove the quick couplers on both hoses and cycle the cylinder in to complete collapse and out to complete extension a couple time. If you can do that without squirting oil all over yourself or your equipment you are better than I......

 

[ray66v]

You can use a rubber tipped blow gun with, low pressure compressed air, to actuate the cylinders, after taking the hoses loose.

It will empty them, and blow oil all over the place. If you're careful, you can catch most of it. That's what we do before disassembling them, to get the oil out.

How about, if you wait until you are ready to do your 50 hour, (assuming you will be doing one), hook all them up, and cycle them, right before you drain the transmission?

 

[gwdixon]

How about, if you wait until you are ready to do your 50 hour, (assuming you will be doing one), hook all them up, and cycle them, right before you drain the transmission?

This idea has a great deal of merit.

Just cycle the cylinders several times on with each piece of equipment attached. Then change the hydraulic oil immediately and realize that you have done a great job that likely no body else would have done.

If you are OCD, then do the whole process again in 100 hours and you'll have everything 99% flushed. The hydraulic fluid in the implements will never need to be serviced again.

As an example, my '14 Honda Odyssey has dumb transmission that can only be drained about 30%. The required service is to drain and top off, drive for a couple of days, drain again, drive again, and finally do a third drain and fill. Supposed to be good for 90K miles, I believe.

 

[IslandTractor]

This idea has a great deal of merit.

Just cycle the cylinders several times on with each piece of equipment attached. Then change the hydraulic oil immediately and realize that you have done a great job that likely no body else would have done.

If you are OCD, then do the whole process again in 100 hours and you'll have everything 99% flushed. The hydraulic fluid in the implements will never need to be serviced again.

As an example, my '14 Honda Odyssey has dumb transmission that can only be drained about 30%. The required service is to drain and top off, drive for a couple of days, drain again, drive again, and finally do a third drain and fill. Supposed to be good for 90K miles, I believe.

That would only mean that the dirtiest fluid (that which is still in the transmission) would be cycled into the implements, some of which would actually contain cleaner than average fluid if they haven't been used in a while.

Keep it simple.

 

[ray66v]

That would only mean that the dirtiest fluid (that which is still in the transmission) would be cycled into the implements, some of which would actually contain cleaner than average fluid if they haven't been used in a while.

Keep it simple.

If he does it right at 50 hours, how "dirty" can the fluid be, it's still new???"

Mine was as clean as what I put back in.


There is far too much obsessing over oil.

Change it, don't change it, it's going to be alright, either way.