Which Pumps??
 

I have two TRS drives on a 30' Scarab and the trim pumps suck. One has completely stopped working with regards to dropping the drive and oil leaks everywhere. I was told that I could and should use newer style pumps because they move the drive faster.
Is this true? and What am I looking for?

Thanks for any insight.

Bill

I,m not sure which pump you may need but I do know they made them pumps 2 ways.One was low pressure/high volume and the other was high pressure/low volume.I don't know if the trim cylinders work with both designs.Hopefully some one will join in with a answer.I'd like to know myself.Mine work fine and don't leak a bit but their sloooo!I also know different ones have different size fittings on the hydraulic lines inside the boat.

Thanks Jim, I had no idea those two options were out there. I wasn't even thinking of volume vs. pressure. I was simply thinkin speed. Somebody educate us

Here's a little more info.If you have the high pressure/low volume pump you will have an external reverse lock valve which is located on top of the transmission.Two of your hydraulic lines will be running to it.It stops flow of fluid when you are in reverse so you can't operate your trim system which could cause damage to your system.The low pressure/high volume pump doesn't have this external set-up.

After doing some research it appears the same trim cylinders were used through out the TRS years ,#47342A23.However several different pumps were used.Most resent was the Oildyne with plastic reservoir which was also used on Alpha's & Bravo's #865380A13.You still might have issues with the size of the fittings on your hydraulic lines inside th boat.You could probably find fittings to adapt if needed.I bought a new Transom/Gimble/Bellhousing assembly and the hyd. lines were larger.I ended up using my old junction block and lines.

Ok so I can't just go out and buy some Bravo trim pumps. They need to be specific to the TRS drives? I was really hoping in the process of replacing I could upgrade to something that moved a little faster. FWIW I have metal reservoirs

They also made that same Oildyne pump with a round metal reservoir.It looks like an oil filter.They were both used on the TRS at one time.These are the latest type pumps made and used on Alpha's & Bravo's also.Same numbers as the one's used on TRS's.If you have a pump with a square metal reservoir this is a Prestolite pump.Their the old style slow pumps.If you look on ebay under "Mercruiser trim pumps" they have over 40 pumps both the old Prestolite and the newerOildyne.Like I mentioned earlier the only problem you may have is the size of the fittings on the hyd. lines especially if you have a Prestolite pump now.

the replacment pump for your application will have to come from merc it will be the new syle oildyne pump with the internal reverse lock valve it will also say LOW FLOW on the box if you use any thing else you may be subjecting you or some one else to some danger from explosion (lines,cylinders,or pump) if wil also have all the fittings and instructions in the box.....

Thanks guys for the info.

A Bravo trim 0pump will work just fine. I,ve used them, and never had a problem. The drives respone quicker.

What he said !!!!:ernaehrung004:

I replaced a oildyne TRS pump with a "bravo" pump last summer. The only difference I saw was the mounting bracket and plastic reservoir on the bravo. Pump worked good, actually faster and quieter than my other old oildyne pump.

However, you mentioned leaking and spraying oil? If thats happening, something else is wrong, and not the pump.

Do these lines get junk built up in them?? Anybody got pumps forsale??

Has anyone used bravo trim pumps for a Speedmaster? I have old Prestolite pumps, and one is not holding pressure. Anyone have a prestolite valve body that is any good?

I had the same problem recently with my TRS. I swore it was the prestolite pump valvebody and even tried the valve bodies off 2 other pumps. Finally I sent my valve body in for a rebuild (go2marine.com). After that it still would drop. I took apart the cylinders and the pistons on both were loose. There's a bolt that threads into the end of the ram shaft to hold the piston on.The piston has 7 check balls in it and when the bolt comes loose it loosens the tension on the check ball springs. If it gets loose enough the springs will actually fall out. I tightened them down and replaced all the o-rings which I bought at the local hardware store for like $2 per cylinder and now it works fine.

I found the answer, courtesy of Galen at Speedmasters-inc.

Anyway, a Bravo pump will "work"- sort of. The bravo pumps produce only about 2800 psi up/500 psi down, whereas the old Prestolite pumps and the SSM Oildynes produce in excess of 4000 psi up/1900 psi down.

Anyway, thanks for the input. I've already been through my rams and rebuilt them. For some reason, I actually had one of the shock pistons with the check balls you discussed, and the rest were solid. I thought that I might have been having trouble with the check ball setup leaking, so I welded up the passages to make it a solid piston.

In troubleshooting yesterday, I hooked the offending drive up to my trim tab pump. I then did the same ratchet strap test I'd done before. Using a big 5000 lb ratchet strap doubled up to a trailer crossmember, I hauled on it as hard as I could, and instead of pulling the drive in, it held pressure. Furthermore, the straps rang the same note after leaving it that way for over an hour, and the drive indicator didn't even budge. So, I am fairly convinced the problem lies in the pump.

I tore it down, and cleaned everything, and tried to increase the spring preload against the check balls, but I think I did that on that drive once before, and there wasn't any more adjustment left. Long story short, ordered a "new to me" Prestolite pump this morning. I toyed with the idea of just upgrading to SSM VI Oildynes, but I like how the old prestolites sound, the big oil reservoir, and I've spent more than enough money on other issues that I'll take the $200 fix over a $1200+ upgrade.