Can you use the old GM Power Steering pump in place of the Mercs? Is there any difference other than price? This is on a boat with twin ram external assist.

I've been using one for about 5 years on a 575SCi
with WPM external steering.

It's not like electrical/fuel items where things like
flameproofing is an issue. I believe the only difference
between the auto parts store pump and the one
you get from Merc. is that Merc. paints it for
corrosion control.

Pesky Varmint

Yes you can.

I also use a GM pump (actually Summit automotive pump - same style) - the only thing I had to do is cut off the merc fitting from my hose and switch it to an automotive flare fitting.

I had this done in 10 minutes at my local automotive. The steering is perfectly smooth, no orifice changes necessary at the inlet - even with full hydraulic steering at an idle.

If memory serves, I think I saved $350 going the summit route.

The automotive pump limits you to that reservoir size, unless you have an adapter cap, which I was never fond of. The automotive pumps also don't put out the same pressure. I'd talk to your steering manufacturer for suggestions.

The automotive pumps can be made to work but after it's all said & done, you might not be saving anything.

What I did it the past was buy a automotive pump and replace the reservoir with a merc reservoir from a bad merc pump. If you want a really good pump send your pump to Turnone he sets them up for all types of racing. He did the pump on my car.

I would think you could buy the automotive pump and reuse the reservoir and pressure control spring, shims from the marine pump and end up with the merc rated output pressure. What do you think?

BT

The orfice jet I found was diff . On my 89 Scarab I got a pump for a 70 Chevelle and it was close I ended up reusing the old orfice and outer housing off the boat and the new guts.


Here is some om my 500efi pump
http://www.offshoreonly.com/forums/s...power+sterring