Pre-Alpha Hydraulic Fluid. Seloc says ATF. What do you say?

[cheburashka]

I just read a couple of posts where folks were raked over the coals for using ATF in a trim pump. Mine has a serial number ending in an "A" and Seloc says that means it takes Type A ATF. Will I end up regretting this? What makes the Quicksilver fluid different? Water absorption?

Thanks

 

[Bondo]

Re: Pre-Alpha Hydraulic Fluid. Seloc says ATF. What do you say?

I Didn't see those posts,.......
But,.......

Regardless of the serial #,....... ATF will work Just Fine...... Any Type of ATF at That.......

 

[cheburashka]

Re: Pre-Alpha Hydraulic Fluid. Seloc says ATF. What do you say?

Aww, man. I stood there looking at all those bottles on the shelf at Walmart: Type F, Dextron, Type A, thinking "I remember what happened when I put the wrong one in my Corvair." So they all work the same in a trim system?

The posts I was talking about were discussing Alphas and Bravos, which apparently don't use ATF.

 

[Bondo]

Re: Pre-Alpha Hydraulic Fluid. Seloc says ATF. What do you say?

Over the years,.. Merc. has recommended ATF,.. Engine Oil,...And of course, Their Own Oils......

All of the Trimpumps are about the Simplest Hydrualic system going...........
They'll function with Any Oil that's less than,.... Oh, say 50w............

 

[skibug]

Re: Pre-Alpha Hydraulic Fluid. Seloc says ATF. What do you say?

Yep, the pumps are not too particular as to what fluid they will pump as long as it's not sludge. I have used ATF (all kinds and brands) in my boats for years with no ill effects.

 

[Don S]

Re: Pre-Alpha Hydraulic Fluid. Seloc says ATF. What do you say?

First of all, let me agree with the previous posters. They will (and do) work on oil and ATF and it won't hurt to use either. But, what your Seloc manual gave you was only part of the information and not exactly correct.
This is from the Mercruiser service manual #1 for the 63 to 73 models:

1. Low pressure white pumps use SAE 10W30 4-cycle engine oil.
2. High pressure white pumps use type "A" suffix "A" transmission fluid.
3. Large reservoir high and low pressure black pump use 20W MS rated oil.

Then under the heading Identification of Hydraulic pumps you find this statement.

To determine whether a large reservoir (White) pump is low pressure type, examine valve body and gear assembly on hydraulic pump. If pump is lower pressure type, letter "A" is stamped after number 105255. If letter "A" does not appear after the number, pump is higher pressure type and must not be used as a replacement for small reservori white pump.

So, as you see there is no letter A after any serial numbers that indicates you use ATF instead of motor oil.

Also, since I would assume you are asking because of your 71 Glasply with a 140, you would have the black pump that is high and low pressure and would use 20W.

 

[Alumarine]

Re: Pre-Alpha Hydraulic Fluid. Seloc says ATF. What do you say?

Thanks Don.
I was just wondering this morning if I should continue to use 10W30 in my new to me large resevoir black pump.

Your post was most timely.