ron7000
Banned
- Joined
- Jul 10, 2004
- Messages
- 498
have an old mercruiser 233 that's been repowered, but still running the original transom assembly, shift plate, and trim cylinders. Last year the original trim pump (from 1976) crapped out. It was replaced with a brand new 2004/5 model volvo trim pump. All the reverse lock out hydarulics are now contained on the pump or so I'm told, so the hydraulic lines go directly from the pump down thru the transom to the 4-way splitter thing which then go to the trim cylinders. All that I'm ok with and the pump seems to work fine. The drive currently has no problem coming up... and the trim pump sounds normal when doing this.
However, when going down the pump sounds completely different. I think it's air in the line and the pump is cavitating but I don't know. You know when you would normally trim down any merc drive and it bottoms out and the trim pump then sounds different, well this one has that 'different' sound all the time when going down. Then when it bottoms out you can barely recognize a change in sound, which I think you should expect. I also know when the pump was installed, the guys doing it said it would self bleed air so all the hydraulic lines were simply connected and the job was said to be finished. Since the beginning, it first started out crappy going up but somewhat quickly cleared out and now comes up fast and sounds good the whole way. Going down at first it did not, unless you helped it with decent force (this was on land). The drive has been cycled up and down many times, to the point now where I mf everyone and everything when I do it again hoping for better down performance. After I don't know how many up and downs and with boat in the water,the drive has a better tendency to go down by itself without any help- either by hand or with boat in forward gear.
Also, the trim cylinders are not original, they are "ebay" brand from a couple years ago, and are in good condition. When I first installed them, on the original pump when that was working, everything worked great. So I have no solid reason to believe the trim cylinders are the problem.
So my questions are:
do volvo pumps just sound like this?
do I have air in the lines on the down side, is that a common problem?
I don't know that much about the original Merc #1 trim cylinders, could my problem be in there?
thanks.
However, when going down the pump sounds completely different. I think it's air in the line and the pump is cavitating but I don't know. You know when you would normally trim down any merc drive and it bottoms out and the trim pump then sounds different, well this one has that 'different' sound all the time when going down. Then when it bottoms out you can barely recognize a change in sound, which I think you should expect. I also know when the pump was installed, the guys doing it said it would self bleed air so all the hydraulic lines were simply connected and the job was said to be finished. Since the beginning, it first started out crappy going up but somewhat quickly cleared out and now comes up fast and sounds good the whole way. Going down at first it did not, unless you helped it with decent force (this was on land). The drive has been cycled up and down many times, to the point now where I mf everyone and everything when I do it again hoping for better down performance. After I don't know how many up and downs and with boat in the water,the drive has a better tendency to go down by itself without any help- either by hand or with boat in forward gear.
Also, the trim cylinders are not original, they are "ebay" brand from a couple years ago, and are in good condition. When I first installed them, on the original pump when that was working, everything worked great. So I have no solid reason to believe the trim cylinders are the problem.
So my questions are:
do volvo pumps just sound like this?
do I have air in the lines on the down side, is that a common problem?
I don't know that much about the original Merc #1 trim cylinders, could my problem be in there?
thanks.