Hydro fluid change?

[clueless 3,012]

So I may change the fluid in my new to me '77 C160 auto this weekend weather permitting, it hasn't been above 57 degrees in 3 days . As I said earlier it looks to be ATF, I'll know for sure when I drain it, I plan to use Dex/Merc if it is. This is my first WH hydro, should I still lift the front end to drain or not since there is no hump, how much fluid do I need to refill it with a new filter? Is there a bleed valve, the only hydro I've done a fluid change is my '97 Simplicity Sovereign, it has a bleed valve, any other advice?

[Sarge 3,463]

That year/model should have the piston to piston hydro and use 10w30. Some types of motor oil can have a red hue to it - the best way to check is when draining it with a light from behind the oil stream. Besides that, ATF type fluids feel completely different and have a very distinct odor compared to engine oils - that is the true way to tell what is in it. Make sure to use a proper hydro filter for it as well. Shouldn't have to raise the front end to drain it, but it can help to clear any sludge in the case. I always drain mine after working them fairly hard to get the oil well up to temperature, it helps to clean them out as well. There is no bleeder valve, just starting it, engaging the transmission itself will bleed the system. You can run it a little on jack stands if you like, but not necessary. Make sure to clean the area around the filter very thoroughly before removing it to prevent dirt from getting inside. Once you refill it and run it for a bit, let it sit a few hours to verify the oil level. 

 

Sarge

[oliver2-44 9,872]

@Sarge covered it well.  When I changed oil in my 1974 C-160 there was an unbelievable amount of black sludge.  The old filter was a red Toro one so I suspect it had not been changed for a long long time.  So I picked the front up and let it sit to drain a little more sludge out. Then I set it back down and flushed some diesel through the bottom of the case and picked up the front and let it drip out to drain it well.  I did not run it as I didn't want to get diesel in the hydro pump, motor, valves.  I would only do the diesel case flush if it had a lot of sludge, like mine did.  I got about 3-3/4 qt of Mobil 1 10/30 in it and it showed full on dipstick.  I ran it and it self primed.  Drove it around and added more oil several times.  It took about 4-3/4 qt oil total.  Since it was so dirty, I ran it about 10 hours light duty work and then changed the oil and filter again.  After another 30 hours of hard work, oil still looks clean on dipstick.  Its now a strong worker.

[squonk 41,346]

If motor oil, Mobil 1 10/30 and a Napa 1410 filter. 

[bc.gold 3,403]

Save the old oil, dilute with a solvent to allow particles to settle out, after a day or so decant 90% of the liquid then the last 10% into a plastic or aluminum container. Use a magnet to see just how much metallic material your able to pull out.

 

The magnetic material should be examined for large shiny flakes these will be an alloy with chromium probably from bearings or gears,  the darker oxidized grit will more than likely be from the casting with a thrust plate or shim missing and brassy particles will be from thrust washers or on the case of piston to piston hydro's from slipper heads on the pistons.

 

I always split my filters open to examine the contents.

 

From this you can decide if its time to overhaul.

Edited January 26, 2019 by bcgold

[clueless 3,012]

Next question, is filling this hydro going to be as tedious ( slow) as the 8sp?

[pfrederi 17,885]

19 minutes ago, clueless said:

Next question, is filling this hydro going to be as tedious ( slow) as the 8sp?

Can be worse...more oil to get in

 

Take one of the bolts out of the top of the transaxle that hold the fender bracket to vent.  Just be sure the area is clean

[ztnoo 2,298]

@clueless,

 

On 1/25/2019 at 10:46 AM, clueless said:

it hasn't been above 57 degrees in 3 days

 

That's about the saddest story I've heard in a long, long time. 

You need to come up north of the Ohio River and spend a little time to know what REAL cold weather is like.

Check out this reading we had from a little less than two weeks ago.

I guarantee you won't be wearing a light nylon windbreaker jacket in these conditions.