Trim pump high volume

frank246

Petty Officer 1st Class
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Jul 18, 2009
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293
I have an older square sump Prestolite trim pump and a later style Oildyne with the plastic tank one.
The Prestolite is rated high pressure-low volume, the Oildyne low pressure-high volume
Do the later trim rams have larger diameter pistons to compensate the lower pressure?
 

Bondo

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Apr 17, 2002
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71,082
Re: Trim pump high volume

Ayuh,... They do, but I've used the pumps interchangeably, without Any issues...

The barge I've run for over 10 years now has the small 1" rams, 'n the late model plastic tanked pump...
 

frank246

Petty Officer 1st Class
Joined
Jul 18, 2009
Messages
293
Re: Trim pump high volume

Great...tnx! Now I only have to adapt to the older 1/8 thread lines...
 

Bondo

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Re: Trim pump high volume

Ayuh,... Automotive brake lines use the same fittings,...
I did mine by brazin' a piece, 'n nut onto the line-end...
 

frank246

Petty Officer 1st Class
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Jul 18, 2009
Messages
293
Re: Trim pump high volume

Automotive...didnt thought `bout that....yet. I might find some "spark protected" ones :)
Why is it they recommend engine oil instead of hydraulic fluid or atf?
Engine oil foams more in a gear pump id say...
 

Bondo

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Staff member
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Apr 17, 2002
Messages
71,082
Re: Trim pump high volume

Ayuh,... It's as simple a Hyd.pump as there is,...
It'll work just fine with about any oil lighter than say 60wt...
Lighter is Better though,...
I use ATF, or Hyd.oil,.. Whichever is handy...

Over the years, Merc has reccommended about All of it at 1 time or another...
My guess motor oil, because it's handy...;)
 
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