Replacing the Tilt/Trim pump

[essveedub]

Hi - new to the forum, but I've been browsing it for quite a while...

I have a 1976 Glastron T-179 with a Mercruiser 140 - pre-Alpha (?) leg.

My trim pump has been losing oil, and it looks like it's mainly from the shift plate mounted reverse lock valve. I'm gonna try to dismantle it and replace o-rings to see if that'll cure the leak. If that doesn't do it, I will consider replacing the trim pump with a new high pressure/low volume pump unit. These pumps have the reverse lock valve built in. I'd like to do that anyway, but the price of those units range from $550 - $700+ USD, so I'm giving the original valve another chance...

My question is: If I do decide to go with a new pump, what else is required? Will it use all the existing hydralic line connections, wiring, etc.? For anyone who has done this - do the new pumps come with retrofit instructions? Anyone know where I can find a how-to guide?

Thanks,

essveedub

 

[fishrdan]

Re: Replacing the Tilt/Trim pump

I did what you are looking to do, replaced an old Prestolite pump with the newer Oildyne pump. The hydraulic fittings on the pumps are different sizes (Prestolite bigger) so you will need to address this, I used new style hoses and new style manifold to get around this problem, I had them. You will need to keep the reverse lock valve since it's an anchor point for the shift cables, I removed it, filled it with oil and plugged the ports. It was leaking on me too, but after taking it out of the pressurized hydraulic system it hasn't leaked. The trim ram hoses on the old and new style manifolds use the same size fittings, so the manifolds are interchangeable, as far as the trim ram hoses go.

My 72 Mercruiser uses a hydraulic trim position sender (mounted on the transom plate) that I had to plumb into the system, but if your 76 has the gimble ring mounted electric trim sensors you can go straight from the pump to the manifold.

If all your hydraulic lines are in good condition and you can just swap the pumps, the biggest hurdle would be adapting the small hose fittings of the old lines to the bigger flared fittings of the new pump. From what I remember, the flare fittings on the Oildyne pump are removable, so you should be able to remove them and get smaller flare fittings.

I think this has been discussed here a couple times, so do a search.

 

[essveedub]

Re: Replacing the Tilt/Trim pump

Thanks fishrdan!

I will get new style hose and manifold when I put the new one in (if my reverse lock valve repair attempt doesn't work)

Just to clarify:

- the manifold you refer to is the hose connector mounted to the gimbal housing? The two new style hoses will connect from the pump side and run thru the transom to the manifold - I can use the existing 4 hoses to the rams with the new manifold, correct?

- I can take the old reverse lock valve out of the system, but leave it intact and on the shift plate filled with oil and plugged.

I do have the electric trim sensors. Matter of fact - they've never been hooked up - boat never had a trim gauge. The boat only has had a dash mounted toggle switch for up and down.I think that with a new pump I will get new sensors and trim gauge at the same time!

Thanks again!

 

[zbnutcase]

Re: Replacing the Tilt/Trim pump

Thanks fishrdan!

I will get new style hose and manifold when I put the new one in (if my reverse lock valve repair attempt doesn't work)

Just to clarify:

- the manifold you refer to is the hose connector mounted to the gimbal housing? The two new style hoses will connect from the pump side and run thru the transom to the manifold - I can use the existing 4 hoses to the rams with the new manifold, correct?

- I can take the old reverse lock valve out of the system, but leave it intact and on the shift plate filled with oil and plugged.

I do have the electric trim sensors. Matter of fact - they've never been hooked up - boat never had a trim gauge. The boat only has had a dash mounted toggle switch for up and down.I think that with a new pump I will get new sensors and trim gauge at the same time!

Thanks again!

Yup you got it!

 

[fishrdan]

Re: Replacing the Tilt/Trim pump

I had to file 1 mounting hole of the new style manifold to fit my 72 gimble housing, the mounting bolt holes were a touch too narrow, but easily taken care of with a dremel.

For the pump, check DB electric, I saw they have the Oildyne pumps for a good price. Don't know if it's aftermarket, for the price I would assume so.