prestolite tilt pump rebuild question with pics!

slag

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Jul 17, 2009
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My boat is a 1972 tri hull with a 72 evinrude electric shift. Motor runs great, boat is good also, however, the tilt has always leaked down and doesn't work correctly.

I took the pump apart last winter and have finally cleaned it up and am ready to put it back together, but i cant remember where all the parts go. My hope is that someone can assist me with this. There are only a few, but I know its important to get them in the correct spots.

2hnaujd.jpg


There are 3 check balls and a spring. I think the two smaller check balls go in the holes to the right of the gears in the piece on the right. I think the larger check ball goes in the bottom hole (cant really see it in the pic), on the left and then the spring fits over it (bottom of the spring has what appears to be a brass holder that fits around the check ball.

Here's another pic with the pieces in place.

qs5guo.jpg


Does this look right? Also, in the picture below, there is a long shaft that goes down to the bottom. I don't think there is supposed to be anything in here.

21afrfd.jpg


Thanks for your help! I remade the main gasket and am using new o rings on the bolts to keep the fluid in.
 

slag

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Messages
471
Re: prestolite tilt pump rebuild question with pics!

I can provide more pictures if anyone needs them for clarification. I know this pump was only made a few years, but I need to get it working as I want to sell this boat and it will be more difficult without power tilt. This is a tilt pump only also.
 

boobie

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Nov 5, 2009
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Re: prestolite tilt pump rebuild question with pics!

Sorry, but never had one apart but maybe some on here will chime in who has.
 

EN2

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Nov 19, 2007
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404
Re: prestolite tilt pump rebuild question with pics!

On the bottom of your pic the large steel ball goes in first. On the top of your pic the round cone shaped part with the slots. This a valve which must be removed to replace a very small O ring which has probably turned to mush. Grab it with a small pliers and give it a twist while pulling up, you will then see a needle valve with the O ring on it underneath will be a spring. Replacing the O ring will allow the unit to stay up.I rebuilt two of these last year and had good sucess. I think main gasket thickness is critical as the gears to main body housing has to have close tolerance. BRP still has the gasket and pump seal. the small O ring I got from a bearing supply house. dont forget the steel ball on the end of the armature shaft.
 

slag

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Messages
471
Re: prestolite tilt pump rebuild question with pics!

On the bottom of your pic the large steel ball goes in first. On the top of your pic the round cone shaped part with the slots. This a valve which must be removed to replace a very small O ring which has probably turned to mush. Grab it with a small pliers and give it a twist while pulling up, you will then see a needle valve with the O ring on it underneath will be a spring. Replacing the O ring will allow the unit to stay up.I rebuilt two of these last year and had good sucess. I think main gasket thickness is critical as the gears to main body housing has to have close tolerance. BRP still has the gasket and pump seal. the small O ring I got from a bearing supply house. dont forget the steel ball on the end of the armature shaft.

Great news about the bottom check ball/spring. Thats how i did it. I'll remove that valve tonight and replace the O ring. What steel ball on the end of the armature shaft?? I did have two small steel balls/bearings. Did I put those in the correct spots?
 

EN2

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404
Re: prestolite tilt pump rebuild question with pics!

On the commutator end of the armature shaft, there is a small steel ball pushed into the end of it. Size is .156 dia. If there is no hole for it , I wouldnt worry about it The other check valves are in the right place. Are you replacing the O ring on the operating piston?
 

slag

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Re: prestolite tilt pump rebuild question with pics!

yes, I have already purchased one from last fall.
 

EN2

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Re: prestolite tilt pump rebuild question with pics!

Let us know how it works out.
 

slag

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Re: prestolite tilt pump rebuild question with pics!

I see the bearing you are talking about on the end of the shaft. Mine is still there. My brushes were seized, but I got them out, cleaned up the sockets, and the springs were still in great shape. Cleaned off the commutator with emery cloth and got that part put back together finally. Now I just need to mate the electrical part back to the pump itself and fill it up with ATF or oil and see if it works. Crossing my fingers. I'll get to it tomorrow after work.
 

EN2

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Nov 19, 2007
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404
Re: prestolite tilt pump rebuild question with pics!

Use ATF. Dexron / Mercon .
 

slag

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Jul 17, 2009
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471
Re: prestolite tilt pump rebuild question with pics!

Use ATF. Dexron / Mercon .

Got it all back together and it works great. The electric motor was having some initial issues, but after cycling it a dozen or so times, it appears to be working fine. I lifted the engine up last night and this morning it was still holding. I then cycled it down and back up a few times and appears to not leak at the pump and everything is holding like it should.

Thanks for the help and advice!
 

Jakub

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Jul 13, 2014
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Hi, I had very similar doubts with rebuild of this exact type of pump. But I can see in this post that I put all parts in the right places. The only difference is that I did not change the O ring on the operating piston because I did not disassemby it. The electric motor is brand new and works in both directions when disconnected from the pump. But my problem is when the electric motor is assembled with the pump. The piston goes down fast and without any problem with the load (the engine) or without. But even without load the piston goes in reverse direction (up) in pains: Two inches in 100 cycles within an hour (in cycles because all cables and the motor become warm). I am in doubt now if I did everything correct. Has anybody such a problem and any suggestion or resolution? Maybe the O ring on the working piston is the solution? But how to change it?
 

Jakub

Recruit
Joined
Jul 13, 2014
Messages
2
Hi, I had very similar doubts with rebuild of this exact type of pump. But I can see in this post that I put all parts in the right places. The only difference is that I did not change the O ring on the operating piston because I did not disassemby it. The electric motor is brand new and works in both directions when disconnected from the pump. But my problem is when the electric motor is assembled with the pump. The piston goes down fast and without any problem with the load (the engine) or without. But even without load the piston goes in reverse direction (up) in pains: Two inches in 100 cycles within an hour (in cycles because all cables and the motor become warm). I am in doubt now if I did everything correct. Has anybody such a problem and any suggestion or resolution? Maybe the O ring on the working piston is the solution? But how to change it?
 

slag

Chief Petty Officer
Joined
Jul 17, 2009
Messages
471
Sorry, can't help you. I sold the boat a couple years ago and don't remember
 
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